Introduction

The following are the events for OpenJDK 12 (jdk-12.0.2+10, permalink, 12-September-2025). The events are collected from the event configuration and the source code. Visit the jfreventcollector repository for more information. This is also the place you can contribute additional event descriptions, if you don't want to contribute them directly to the OpenJDK. The site generator lives on GitHub, too.

This page is maintained by Johannes Bechberger of the SapMachine team at SAP and contributors.

Some events have fake end times/durations; these are hidden in the event description here.

Flight Recorder

DumpReason

default profiling startTime 11 17 21 25 26

Category: Flight Recorder

Who requested the recording and why

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/jfr/recorder/repository/jfrEmergencyDump.cpp:

  if (exception_handler) {
    // we are crashing
    if (thread->is_Watcher_thread()) {
      // The Watcher thread runs the periodic thread sampling task.
      // If it has crashed, it is likely that another thread is
      // left in a suspended state. This would mean the system
      // will not be able to ever move to a safepoint. We try
      // to avoid issuing safepoint operations when attempting
      // an emergency dump, but a safepoint might be already pending.
      return;
    }
    prepare_for_emergency_dump(thread);
  }
  EventDumpReason event;
  if (event.should_commit()) {
    event.set_reason(exception_handler ? "Crash" : "Out of Memory");
    event.set_recordingId(-1);
    event.commit();
  }
  if (!exception_handler) {
    // OOM
    LeakProfiler::emit_events(max_jlong, false);
  }
  const int messages = MSGBIT(MSG_VM_ERROR);
  ResourceMark rm(thread);

Configuration enabled
default true
profiling true

Field Type Description
reason string Reason Reason for writing recording data to disk
recordingId int Recording Id Id of the recording that triggered the dump, or -1 if it was not related to a recording

DataLoss

default profiling startTime 11 17 21 25 26

Category: Flight Recorder

Data could not be copied out from a buffer, typically because of contention

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/jfr/recorder/storage/jfrStorage.cpp:

      assert(!buffer->transient(), "invariant");
      assert(buffer->lease(), "invariant");
      storage_instance.control().increment_leased();
      return buffer;
    }
  }
  return acquire_transient(size, thread);
}

static void write_data_loss_event(JfrBuffer* buffer, u8 unflushed_size, Thread* thread) {
  assert(buffer != NULL, "invariant");
  assert(buffer->empty(), "invariant");
  const u8 total_data_loss = thread->jfr_thread_local()->add_data_lost(unflushed_size);
  if (EventDataLoss::is_enabled()) {
    JfrNativeEventWriter writer(buffer, thread);
    writer.write<u8>(EventDataLoss::eventId);
    writer.write(JfrTicks::now());
    writer.write(unflushed_size);
    writer.write(total_data_loss);
  }
}

static void write_data_loss(BufferPtr buffer, Thread* thread) {
  assert(buffer != NULL, "invariant");
  const size_t unflushed_size = buffer->unflushed_size();
  buffer->concurrent_reinitialization();
  if (unflushed_size == 0) {

Configuration enabled
default true
profiling true

Field Type Description
amount ulong: bytes Amount Amount lost data
total ulong: bytes Total Total lost amount for thread

ActiveRecording

default profiling startTime duration stackTrace 11 17 21 25 26

Source src/jdk.jfr/share/classes/jdk/jfr/events/ActiveRecordingEvent.java

Category: Flight Recorder

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/jdk.jfr/share/classes/jdk/jfr/events/ActiveRecordingEvent.java:

@Name(Type.EVENT_NAME_PREFIX + "ActiveRecording")
@Label("Flight Recording")
@Category("Flight Recorder")
@StackTrace(false)
public final class ActiveRecordingEvent extends AbstractJDKEvent {

    @Label("Id")
    public long id;

    @Label("Name")
    public String name;

    @Label("Destination")
    public String destination;

    @Label("Max Age")

src/jdk.jfr/share/classes/jdk/jfr/internal/PlatformRecorder.java:

    private long recordingCounter = 0;
    private RepositoryChunk currentChunk;

    public PlatformRecorder() throws Exception {
        repository = Repository.getRepository();
        Logger.log(JFR_SYSTEM, INFO, "Initialized disk repository");
        repository.ensureRepository();
        jvm.createNativeJFR();
        Logger.log(JFR_SYSTEM, INFO, "Created native");
        JDKEvents.initialize();
        Logger.log(JFR_SYSTEM, INFO, "Registered JDK events");
        JDKEvents.addInstrumentation();
        startDiskMonitor();
        activeRecordingEvent = EventType.getEventType(ActiveRecordingEvent.class);
        activeSettingEvent = EventType.getEventType(ActiveSettingEvent.class);
        shutdownHook = SecuritySupport.createThreadWitNoPermissions("JFR: Shutdown Hook", new ShutdownHook(this));
        SecuritySupport.setUncaughtExceptionHandler(shutdownHook, new ShutdownHook.ExceptionHandler());
        SecuritySupport.registerShutdownHook(shutdownHook);
        timer = createTimer();
    }


    private static Timer createTimer() {
        try {
            List<Timer> result = new CopyOnWriteArrayList<>();

src/jdk.jfr/share/classes/jdk/jfr/internal/PlatformRecorder.java:

        chunk.finish(time);
        for (PlatformRecording r : getRecordings()) {
            if (r != ignoreMe && r.getState() == RecordingState.RUNNING) {
                r.appendChunk(chunk);
            }
        }
    }

    private void writeMetaEvents() {

        if (activeRecordingEvent.isEnabled()) {
            for (PlatformRecording r : getRecordings()) {
                if (r.getState() == RecordingState.RUNNING && r.shouldWriteMetadataEvent()) {
                    ActiveRecordingEvent event = new ActiveRecordingEvent();
                    event.id = r.getId();
                    event.name = r.getName();
                    WriteableUserPath p = r.getDestination();
                    event.destination = p == null ? null : p.getText();
                    Duration d = r.getDuration();
                    event.recordingDuration = d == null ? Long.MAX_VALUE : d.toMillis();
                    Duration age = r.getMaxAge();
                    event.maxAge = age == null ? Long.MAX_VALUE : age.toMillis();
                    Long size = r.getMaxSize();
                    event.maxSize = size == null ? Long.MAX_VALUE : size;
                    Instant start = r.getStartTime();

src/jdk.jfr/share/classes/jdk/jfr/internal/instrument/JDKEvents.java:

        X509ValidationEvent.class
    };

    private static final Class<?>[] eventClasses = {
        FileForceEvent.class,
        FileReadEvent.class,
        FileWriteEvent.class,
        SocketReadEvent.class,
        SocketWriteEvent.class,
        ExceptionThrownEvent.class,
        ExceptionStatisticsEvent.class,
        ErrorThrownEvent.class,
        ActiveSettingEvent.class,
        ActiveRecordingEvent.class,
        jdk.internal.event.SecurityPropertyModificationEvent.class,
        jdk.internal.event.TLSHandshakeEvent.class,
        jdk.internal.event.X509CertificateEvent.class,
        jdk.internal.event.X509ValidationEvent.class
    };

    // This is a list of the classes with instrumentation code that should be applied.
    private static final Class<?>[] instrumentationClasses = new Class<?>[] {
        FileInputStreamInstrumentor.class,
        FileOutputStreamInstrumentor.class,
        RandomAccessFileInstrumentor.class,

Configuration enabled
default true
profiling true

Field Type Description
id long Id
name string Name Consider contributing a description to jfreventcollector.
destination string Destination Consider contributing a description to jfreventcollector.
maxAge long: millis Max Age
maxSize long: bytes Max Size
recordingStart long: epochmillis Start Time
recordingDuration long: millis Recording Duration

Examples 3
destination string
[...]_1/code/experiments/jfreventcollector/jfr/sample_UseG1GC.jfr
id long
1
maxAge long: millis
9223372036854775807
maxSize long: bytes
262144000
name string
1
recordingDuration long: millis
9223372036854775807
recordingStart long: epochmillis
1754910293748
stackTrace StackTrace
null
startTime long: millis
201458419375
destination string
[...]_1/code/experiments/jfreventcollector/jfr/sample_UseParallelGC.jfr
id long
1
maxAge long: millis
9223372036854775807
maxSize long: bytes
262144000
name string
1
recordingDuration long: millis
9223372036854775807
recordingStart long: epochmillis
1754910547922
stackTrace StackTrace
null
startTime long: millis
254486400542
destination string
[...]_1/code/experiments/jfreventcollector/jfr/sample_UseSerialGC.jfr
id long
1
maxAge long: millis
9223372036854775807
maxSize long: bytes
262144000
name string
1
recordingDuration long: millis
9223372036854775807
recordingStart long: epochmillis
1754910820635
stackTrace StackTrace
null
startTime long: millis
292497507417

ActiveSetting

default profiling startTime duration stackTrace 11 17 21 25 26

Source src/jdk.jfr/share/classes/jdk/jfr/events/ActiveSettingEvent.java

Category: Flight Recorder

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/jdk.jfr/share/classes/jdk/jfr/events/ActiveSettingEvent.java:

package jdk.jfr.events;

import jdk.jfr.Category;
import jdk.jfr.Label;
import jdk.jfr.Name;
import jdk.jfr.StackTrace;
import jdk.jfr.internal.Type;

@Name(Type.EVENT_NAME_PREFIX + "ActiveSetting")
@Label("Recording Setting")
@Category("Flight Recorder")
@StackTrace(false)
public final class ActiveSettingEvent extends AbstractJDKEvent {

    @Label("Event Id")
    public long id;

    @Label("Setting Name")
    public String name;

    @Label("Setting Value")
    public String value;
}

src/jdk.jfr/share/classes/jdk/jfr/internal/PlatformRecorder.java:

    private RepositoryChunk currentChunk;

    public PlatformRecorder() throws Exception {
        repository = Repository.getRepository();
        Logger.log(JFR_SYSTEM, INFO, "Initialized disk repository");
        repository.ensureRepository();
        jvm.createNativeJFR();
        Logger.log(JFR_SYSTEM, INFO, "Created native");
        JDKEvents.initialize();
        Logger.log(JFR_SYSTEM, INFO, "Registered JDK events");
        JDKEvents.addInstrumentation();
        startDiskMonitor();
        activeRecordingEvent = EventType.getEventType(ActiveRecordingEvent.class);
        activeSettingEvent = EventType.getEventType(ActiveSettingEvent.class);
        shutdownHook = SecuritySupport.createThreadWitNoPermissions("JFR: Shutdown Hook", new ShutdownHook(this));
        SecuritySupport.setUncaughtExceptionHandler(shutdownHook, new ShutdownHook.ExceptionHandler());
        SecuritySupport.registerShutdownHook(shutdownHook);
        timer = createTimer();
    }


    private static Timer createTimer() {
        try {
            List<Timer> result = new CopyOnWriteArrayList<>();
            Thread t = SecuritySupport.createThreadWitNoPermissions("Permissionless thread", ()-> {

src/jdk.jfr/share/classes/jdk/jfr/internal/instrument/JDKEvents.java:

        X509CertificateEvent.class,
        X509ValidationEvent.class
    };

    private static final Class<?>[] eventClasses = {
        FileForceEvent.class,
        FileReadEvent.class,
        FileWriteEvent.class,
        SocketReadEvent.class,
        SocketWriteEvent.class,
        ExceptionThrownEvent.class,
        ExceptionStatisticsEvent.class,
        ErrorThrownEvent.class,
        ActiveSettingEvent.class,
        ActiveRecordingEvent.class,
        jdk.internal.event.SecurityPropertyModificationEvent.class,
        jdk.internal.event.TLSHandshakeEvent.class,
        jdk.internal.event.X509CertificateEvent.class,
        jdk.internal.event.X509ValidationEvent.class
    };

    // This is a list of the classes with instrumentation code that should be applied.
    private static final Class<?>[] instrumentationClasses = new Class<?>[] {
        FileInputStreamInstrumentor.class,
        FileOutputStreamInstrumentor.class,

src/jdk.jfr/share/classes/jdk/jfr/internal/EventControl.java:

    void writeActiveSettingEvent() {
        if (!type.isRegistered()) {
            return;
        }
        for (Map.Entry<String, Control> entry : eventControls.entrySet()) {
            Control c = entry.getValue();
            if (Utils.isSettingVisible(c, type.hasEventHook())) {
                String value = c.getLastValue();
                if (value == null) {
                    value = c.getDefaultValue();
                }
                ActiveSettingEvent ase = new ActiveSettingEvent();
                ase.id = type.getId();
                ase.name = entry.getKey();
                ase.value = value;
                ase.commit();
            }
        }
    }

    public Set<Entry<String, Control>> getEntries() {
        return eventControls.entrySet();
    }

Configuration enabled
default true
profiling true

Field Type Description
id long Event Id
name string Setting Name
value string Setting Value

Examples 3
id long
11
name string
enabled
stackTrace StackTrace
null
startTime long: millis
230196648958
value string
true
id long
24
name string
enabled
stackTrace StackTrace
null
startTime long: millis
199115347333
value string
true
id long
85
name string
threshold
stackTrace StackTrace
null
startTime long: millis
242182403167
value string
0 ms

JVM

JVMInformation

default profiling startTime duration end of every chunk 11 17 21 25 26

Category: Java Virtual Machine

Description of JVM and the Java application

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/jfr/periodic/jfrPeriodic.cpp:

/**
 *  JfrPeriodic class
 *  Implementation of declarations in
 *  xsl generated traceRequestables.hpp
 */
#define TRACE_REQUEST_FUNC(id)    void JfrPeriodicEventSet::request##id(void)

TRACE_REQUEST_FUNC(JVMInformation) {
  ResourceMark rm;
  EventJVMInformation event;
  event.set_jvmName(VM_Version::vm_name());
  event.set_jvmVersion(VM_Version::internal_vm_info_string());
  event.set_javaArguments(Arguments::java_command());
  event.set_jvmArguments(Arguments::jvm_args());
  event.set_jvmFlags(Arguments::jvm_flags());
  event.set_jvmStartTime(Management::vm_init_done_time());
  event.set_pid(os::current_process_id());
  event.commit();
 }

TRACE_REQUEST_FUNC(OSInformation) {

Configuration enabled period
default true beginChunk
profiling true beginChunk

Field Type Description
jvmName string JVM Name
jvmVersion string JVM Version
jvmArguments string JVM Command Line Arguments
jvmFlags string JVM Settings File Arguments
javaArguments string Java Application Arguments
jvmStartTime long: epochmillis JVM Start Time
pid long Process Identifier

Examples 3
javaArguments string
[...]_1/code/experiments/jfreventcollector/.cache/renaissance.jar -t 5 -r 1 all
jvmArguments string
-XX:StartFlightRecording=filename=[...]_1/code/experiments/jfreventcollector/jfr/sample_UseSerialGC.jfr,settings=[...]_1/code/experiments/jfreventcollector/.cache/jfc.jfc -XX:+UseSerialGC
jvmFlags string
null
jvmName string
OpenJDK 64-Bit Server VM
jvmStartTime long: epochmillis
1754910820470
jvmVersion string
OpenJDK 64-Bit Server VM (21.0.7+6-LTS) for bsd-aarch64 JRE (21.0.7+6-LTS), built on 2025-04-15T00:00:00Z by "admin" with clang Apple LLVM 15.0.0 (clang-1500.1.0.2.5)
pid long
97133
startTime long: millis
273456970083
javaArguments string
[...]_1/code/experiments/jfreventcollector/.cache/renaissance.jar -t 5 -r 1 all
jvmArguments string
-XX:StartFlightRecording=filename=[...]_1/code/experiments/jfreventcollector/jfr/sample_UseG1GC.jfr,settings=[...]_1/code/experiments/jfreventcollector/.cache/jfc.jfc -XX:+UseG1GC
jvmFlags string
null
jvmName string
OpenJDK 64-Bit Server VM
jvmStartTime long: epochmillis
1754910293523
jvmVersion string
OpenJDK 64-Bit Server VM (21.0.7+6-LTS) for bsd-aarch64 JRE (21.0.7+6-LTS), built on 2025-04-15T00:00:00Z by "admin" with clang Apple LLVM 15.0.0 (clang-1500.1.0.2.5)
pid long
96009
startTime long: millis
217937005250
javaArguments string
[...]_1/code/experiments/jfreventcollector/.cache/renaissance.jar -t 5 -r 1 all
jvmArguments string
-XX:StartFlightRecording=filename=[...]_1/code/experiments/jfreventcollector/jfr/sample_UseParallelGC.jfr,settings=[...]_1/code/experiments/jfreventcollector/.cache/jfc.jfc -XX:+UseParallelGC
jvmFlags string
null
jvmName string
OpenJDK 64-Bit Server VM
jvmStartTime long: epochmillis
1754910547780
jvmVersion string
OpenJDK 64-Bit Server VM (21.0.7+6-LTS) for bsd-aarch64 JRE (21.0.7+6-LTS), built on 2025-04-15T00:00:00Z by "admin" with clang Apple LLVM 15.0.0 (clang-1500.1.0.2.5)
pid long
96543
startTime long: millis
265731386833

InitialSystemProperty

default profiling startTime end of every chunk 11 17 21 25 26

Category: Java Virtual Machine

System Property at JVM start

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/jfr/periodic/jfrPeriodic.cpp:

  jlong max_size = conf.has_max_size_default_value() ? jmc_undefined_long : conf.max_size();
  EventYoungGenerationConfiguration event;
  event.set_maxSize((u8)max_size);
  event.set_minSize(conf.min_size());
  event.set_newRatio(conf.new_ratio());
  event.commit();
}

TRACE_REQUEST_FUNC(InitialSystemProperty) {
  SystemProperty* p = Arguments::system_properties();
  JfrTicks time_stamp = JfrTicks::now();
  while (p !=  NULL) {
    if (!p->internal()) {
      EventInitialSystemProperty event(UNTIMED);
      event.set_key(p->key());
      event.set_value(p->value());
      event.set_endtime(time_stamp);
      event.commit();
    }
    p = p->next();
  }
}

TRACE_REQUEST_FUNC(ThreadAllocationStatistics) {
  ResourceMark rm;

Configuration enabled period
default true beginChunk
profiling true beginChunk

Field Type Description
key string Key
value string Value

Examples 3
key string
java.vm.name
startTime long: millis
247315611708
value string
OpenJDK 64-Bit Server VM
key string
sun.java.launcher
startTime long: millis
237257250750
value string
SUN_STANDARD
key string
java.vm.specification.vendor
startTime long: millis
212447908916
value string
Oracle Corporation

JVM: Class Loading

ClassLoad

startTime duration eventThread stackTrace 11 17 21 25 26

Category: Java Virtual Machine / Class Loading

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/classfile/systemDictionary.cpp:

          SystemDictionary_lock->wait();
        } else {
          double_lock_wait(lockObject, THREAD);
        }
      } else {
        // If not in SD and not in PH, other thread's load must have failed
        super_load_in_progress = false;
      }
    }
  }
  return NULL;
}

static void post_class_load_event(EventClassLoad* event, const InstanceKlass* k, const ClassLoaderData* init_cld) {
  assert(event != NULL, "invariant");
  assert(k != NULL, "invariant");
  assert(event->should_commit(), "invariant");
  event->set_loadedClass(k);
  event->set_definingClassLoader(k->class_loader_data());
  event->set_initiatingClassLoader(init_cld);
  event->commit();
}


// Be careful when modifying this code: once you have run
// placeholders()->find_and_add(PlaceholderTable::LOAD_INSTANCE),
// you need to find_and_remove it before returning.
// So be careful to not exit with a CHECK_ macro betweeen these calls.
//
// name must be in the form of "java/lang/Object" -- cannot be "Ljava/lang/Object;"
InstanceKlass* SystemDictionary::resolve_instance_class_or_null(Symbol* name,
                                                                Handle class_loader,
                                                                Handle protection_domain,
                                                                TRAPS) {
  assert(name != NULL && !FieldType::is_array(name) &&
         !FieldType::is_obj(name), "invalid class name");

  EventClassLoad class_load_start_event;

  HandleMark hm(THREAD);

  // Fix for 4474172; see evaluation for more details
  class_loader = Handle(THREAD, java_lang_ClassLoader::non_reflection_class_loader(class_loader()));
  ClassLoaderData* loader_data = register_loader(class_loader);
  Dictionary* dictionary = loader_data->dictionary();
  unsigned int d_hash = dictionary->compute_hash(name);

  // Do lookup to see if class already exist and the protection domain
  // has the right access

src/hotspot/share/classfile/systemDictionary.cpp:

// Note: this method is much like resolve_from_stream, but
// does not publish the classes via the SystemDictionary.
// Handles unsafe_DefineAnonymousClass and redefineclasses
// RedefinedClasses do not add to the class hierarchy
InstanceKlass* SystemDictionary::parse_stream(Symbol* class_name,
                                              Handle class_loader,
                                              Handle protection_domain,
                                              ClassFileStream* st,
                                              const InstanceKlass* unsafe_anonymous_host,
                                              GrowableArray<Handle>* cp_patches,
                                              TRAPS) {

  EventClassLoad class_load_start_event;

  ClassLoaderData* loader_data;
  if (unsafe_anonymous_host != NULL) {
    // Create a new CLD for an unsafe anonymous class, that uses the same class loader
    // as the unsafe_anonymous_host
    guarantee(oopDesc::equals(unsafe_anonymous_host->class_loader(), class_loader()), "should be the same");
    loader_data = ClassLoaderData::unsafe_anonymous_class_loader_data(class_loader);
  } else {
    loader_data = ClassLoaderData::class_loader_data(class_loader());
  }

Configuration enabled stackTrace threshold
default false true 0 ms
profiling false true 0 ms

Field Type Description
loadedClass Class Loaded Class Consider contributing a description to jfreventcollector.
definingClassLoader ClassLoader Defining Class Loader Consider contributing a description to jfreventcollector.
initiatingClassLoader ClassLoader Initiating Class Loader Consider contributing a description to jfreventcollector.

Examples 3
definingClassLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/net
initiatingClassLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/net
loadedClass Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/net
hidden boolean
false
modifiers int
17
name string
org/apache/spark/sql/SQLImplicits$$typecreator1$8
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/net
location string
null
name string
null
version string
null
name string
org/apache/spark/sql
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
12
lineNumber int
825
method Method
descriptor string
()V
hidden boolean
false
modifiers int
18
name string
implicits$lzycompute$1
type Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/net
hidden boolean
false
modifiers int
1
name string
org/apache/spark/sql/SparkSession
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/net
location string
null
name string
null
version string
null
name string
org/apache/spark/sql
type FrameType
Interpreted
truncated boolean
false
startTime long: millis
223761224875
definingClassLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/net
initiatingClassLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/net
loadedClass Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/net
hidden boolean
false
modifiers int
17
name string
org/apache/spark/sql/SQLImplicits$$typecreator1$16
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/net
location string
null
name string
null
version string
null
name string
org/apache/spark/sql
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
12
lineNumber int
825
method Method
descriptor string
()V
hidden boolean
false
modifiers int
18
name string
implicits$lzycompute$1
type Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/net
hidden boolean
false
modifiers int
1
name string
org/apache/spark/sql/SparkSession
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/net
location string
null
name string
null
version string
null
name string
org/apache/spark/sql
type FrameType
Interpreted
truncated boolean
false
startTime long: millis
244508432292
definingClassLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/net
initiatingClassLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/net
loadedClass Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/net
hidden boolean
false
modifiers int
1537
name string
scala/reflect/api/Mirrors
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/net
location string
null
name string
null
version string
null
name string
scala/reflect/api
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
0
lineNumber int
-1
method Method
descriptor string
(Ljava/lang/ClassLoader;Ljava/lang/String;[BIILjava/security/ProtectionDomain;Ljava/lang/String;)Ljava/lang/Class;
hidden boolean
false
modifiers int
264
name string
defineClass1
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1025
name string
java/lang/ClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/lang
type FrameType
Native
truncated boolean
false
startTime long: millis
260418131500

ClassDefine

startTime eventThread stackTrace 11 17 21 25 26

Category: Java Virtual Machine / Class Loading

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/classfile/systemDictionary.cpp:

      // For user defined Java class loaders, check that the name returned is
      // the same as that requested.  This check is done for the bootstrap
      // loader when parsing the class file.
      if (class_name == k->name()) {
        return k;
      }
    }
    // Class is not found or has the wrong name, return NULL
    return NULL;
  }
}

static void post_class_define_event(InstanceKlass* k, const ClassLoaderData* def_cld) {
  EventClassDefine event;
  if (event.should_commit()) {
    event.set_definedClass(k);
    event.set_definingClassLoader(def_cld);
    event.commit();
  }
}

void SystemDictionary::define_instance_class(InstanceKlass* k, TRAPS) {

  HandleMark hm(THREAD);
  ClassLoaderData* loader_data = k->class_loader_data();

Configuration enabled stackTrace
default false true
profiling false true

Field Type Description
definedClass Class Defined Class Consider contributing a description to jfreventcollector.
definingClassLoader ClassLoader Defining Class Loader Consider contributing a description to jfreventcollector.

Examples 3
definedClass Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/net
hidden boolean
false
modifiers int
1537
name string
scala/reflect/api/Quasiquotes
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/net
location string
null
name string
null
version string
null
name string
scala/reflect/api
definingClassLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/net
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
0
lineNumber int
-1
method Method
descriptor string
(Ljava/lang/ClassLoader;Ljava/lang/String;[BIILjava/security/ProtectionDomain;Ljava/lang/String;)Ljava/lang/Class;
hidden boolean
false
modifiers int
264
name string
defineClass1
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1025
name string
java/lang/ClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/lang
type FrameType
Native
truncated boolean
true
startTime long: millis
244526148542
definedClass Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/net
hidden boolean
false
modifiers int
1
name string
org/apache/spark/sql/SparkSession$implicits$
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/net
location string
null
name string
null
version string
null
name string
org/apache/spark/sql
definingClassLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/net
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
0
lineNumber int
-1
method Method
descriptor string
(Ljava/lang/ClassLoader;Ljava/lang/String;[BIILjava/security/ProtectionDomain;Ljava/lang/String;)Ljava/lang/Class;
hidden boolean
false
modifiers int
264
name string
defineClass1
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1025
name string
java/lang/ClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/lang
type FrameType
Native
truncated boolean
false
startTime long: millis
260405783125
definedClass Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/net
hidden boolean
false
modifiers int
1537
name string
scala/reflect/internal/transform/Transforms
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/net
location string
null
name string
null
version string
null
name string
scala/reflect/internal/transform
definingClassLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/net
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
0
lineNumber int
-1
method Method
descriptor string
(Ljava/lang/ClassLoader;Ljava/lang/String;[BIILjava/security/ProtectionDomain;Ljava/lang/String;)Ljava/lang/Class;
hidden boolean
false
modifiers int
264
name string
defineClass1
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1025
name string
java/lang/ClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/lang
type FrameType
Native
truncated boolean
false
startTime long: millis
223773870541

ClassUnload

startTime eventThread 11 17 21 25 26

Category: Java Virtual Machine / Class Loading

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/oops/instanceKlass.cpp:

  // Release dependencies.
  ik->dependencies().remove_all_dependents();

  // notify the debugger
  if (JvmtiExport::should_post_class_unload()) {
    JvmtiExport::post_class_unload(ik);
  }

  // notify ClassLoadingService of class unload
  ClassLoadingService::notify_class_unloaded(ik);

#if INCLUDE_JFR
  assert(ik != NULL, "invariant");
  EventClassUnload event;
  event.set_unloadedClass(ik);
  event.set_definingClassLoader(ik->class_loader_data());
  event.commit();
#endif
}

void InstanceKlass::release_C_heap_structures(InstanceKlass* ik) {
  // Clean up C heap
  ik->release_C_heap_structures();
  ik->constants()->release_C_heap_structures();
}

Configuration enabled
default false
profiling false

Field Type Description
unloadedClass Class Unloaded Class Consider contributing a description to jfreventcollector.
definingClassLoader ClassLoader Defining Class Loader Consider contributing a description to jfreventcollector.

Examples 3
definingClassLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/net
startTime long: millis
246689218292
unloadedClass Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/net
hidden boolean
true
modifiers int
4112
name string
org.renaissance.jdk.streams.MnemonicsCoderWithStream$$Lambda+0x00000070067df9c0/1599801234
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/net
location string
null
name string
null
version string
null
name string
org/renaissance/jdk/streams
definingClassLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/net
startTime long: millis
226116270416
unloadedClass Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/net
hidden boolean
true
modifiers int
4112
name string
org.renaissance.jdk.streams.MnemonicsCoderWithStream$$Lambda+0x000000700688c8d0/417685665
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/net
location string
null
name string
null
version string
null
name string
org/renaissance/jdk/streams
definingClassLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/net
startTime long: millis
267243164958
unloadedClass Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/net
hidden boolean
false
modifiers int
17
name string
scala/collection/immutable/Vector6
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/net
location string
null
name string
null
version string
null
name string
scala/collection/immutable

JVM: Code Cache

CodeCacheFull

default profiling startTime eventThread 11 17 21 25 26

Category: Java Virtual Machine / Code Cache

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/code/codeCache.cpp:

      ttyLocker ttyl;
      tty->print("%s", s.as_string());
    }

    if (heap->full_count() == 0) {
      if (PrintCodeHeapAnalytics) {
        CompileBroker::print_heapinfo(tty, "all", "4096"); // details, may be a lot!
      }
    }
  }

  heap->report_full();

  EventCodeCacheFull event;
  if (event.should_commit()) {
    event.set_codeBlobType((u1)code_blob_type);
    event.set_startAddress((u8)heap->low_boundary());
    event.set_commitedTopAddress((u8)heap->high());
    event.set_reservedTopAddress((u8)heap->high_boundary());
    event.set_entryCount(heap->blob_count());
    event.set_methodCount(heap->nmethod_count());
    event.set_adaptorCount(heap->adapter_count());
    event.set_unallocatedCapacity(heap->unallocated_capacity());
    event.set_fullCount(heap->full_count());
    event.commit();

Configuration enabled
default true
profiling true

Field Type Description
codeBlobType CodeBlobType Code Heap Consider contributing a description to jfreventcollector.
startAddress ulong: address Start Address
commitedTopAddress ulong: address Commited Top
reservedTopAddress ulong: address Reserved Top
entryCount int Entries
methodCount int Methods
adaptorCount int Adaptors
unallocatedCapacity ulong: bytes Unallocated
fullCount int Full Count

CodeCacheStatistics

default profiling startTime every chunk 11 17 21 25 26

Category: Java Virtual Machine / Code Cache

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/jfr/periodic/jfrPeriodic.cpp:

TRACE_REQUEST_FUNC(CompilerConfiguration) {
  EventCompilerConfiguration event;
  event.set_threadCount(CICompilerCount);
  event.set_tieredCompilation(TieredCompilation);
  event.commit();
}

TRACE_REQUEST_FUNC(CodeCacheStatistics) {
  // Emit stats for all available code heaps
  for (int bt = 0; bt < CodeBlobType::NumTypes; ++bt) {
    if (CodeCache::heap_available(bt)) {
      EventCodeCacheStatistics event;
      event.set_codeBlobType((u1)bt);
      event.set_startAddress((u8)CodeCache::low_bound(bt));
      event.set_reservedTopAddress((u8)CodeCache::high_bound(bt));
      event.set_entryCount(CodeCache::blob_count(bt));
      event.set_methodCount(CodeCache::nmethod_count(bt));
      event.set_adaptorCount(CodeCache::adapter_count(bt));
      event.set_unallocatedCapacity(CodeCache::unallocated_capacity(bt));
      event.set_fullCount(CodeCache::get_codemem_full_count(bt));
      event.commit();
    }
  }

Configuration enabled period
default true everyChunk
profiling true everyChunk

Field Type Description
codeBlobType CodeBlobType Code Heap Consider contributing a description to jfreventcollector.
startAddress ulong: address Start Address
reservedTopAddress ulong: address Reserved Top
entryCount int Entries
methodCount int Methods
adaptorCount int Adaptors
unallocatedCapacity ulong: bytes Unallocated
fullCount int Full Count

Examples 3
adaptorCount int
0
codeBlobType CodeBlobType
CodeHeap 'non-profiled nmethods'
entryCount int
5046
fullCount int
0
methodCount int
5046
reservedTopAddress ulong: address
4806557696
startAddress ulong: address
4683644928
startTime long: millis
248852726458
unallocatedCapacity ulong: bytes
113191680
adaptorCount int
0
codeBlobType CodeBlobType
CodeHeap 'profiled nmethods'
entryCount int
6745
fullCount int
0
methodCount int
6745
reservedTopAddress ulong: address
5365776384
startAddress ulong: address
5242880000
startTime long: millis
233951617250
unallocatedCapacity ulong: bytes
100141312
adaptorCount int
0
codeBlobType CodeBlobType
CodeHeap 'profiled nmethods'
entryCount int
3547
fullCount int
0
methodCount int
3547
reservedTopAddress ulong: address
4678795264
startAddress ulong: address
4555898880
startTime long: millis
242749606083
unallocatedCapacity ulong: bytes
110910720

CodeCacheConfiguration

default profiling startTime end of every chunk 11 17 21 25 26

Category: Java Virtual Machine / Code Cache

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/jfr/periodic/jfrPeriodic.cpp:

      event.set_startAddress((u8)CodeCache::low_bound(bt));
      event.set_reservedTopAddress((u8)CodeCache::high_bound(bt));
      event.set_entryCount(CodeCache::blob_count(bt));
      event.set_methodCount(CodeCache::nmethod_count(bt));
      event.set_adaptorCount(CodeCache::adapter_count(bt));
      event.set_unallocatedCapacity(CodeCache::unallocated_capacity(bt));
      event.set_fullCount(CodeCache::get_codemem_full_count(bt));
      event.commit();
    }
  }
}

TRACE_REQUEST_FUNC(CodeCacheConfiguration) {
  EventCodeCacheConfiguration event;
  event.set_initialSize(InitialCodeCacheSize);
  event.set_reservedSize(ReservedCodeCacheSize);
  event.set_nonNMethodSize(NonNMethodCodeHeapSize);
  event.set_profiledSize(ProfiledCodeHeapSize);
  event.set_nonProfiledSize(NonProfiledCodeHeapSize);
  event.set_expansionSize(CodeCacheExpansionSize);
  event.set_minBlockLength(CodeCacheMinBlockLength);
  event.set_startAddress((u8)CodeCache::low_bound());
  event.set_reservedTopAddress((u8)CodeCache::high_bound());
  event.commit();
}

Configuration enabled period
default true beginChunk
profiling true beginChunk

Field Type Description
initialSize ulong: bytes Initial Size
reservedSize ulong: bytes Reserved Size
nonNMethodSize ulong: bytes Non-nmethod Size
profiledSize ulong: bytes Profiled Size
nonProfiledSize ulong: bytes Non-profiled Size
expansionSize ulong: bytes Expansion size
minBlockLength ulong: bytes Minimum Block Length
startAddress ulong: address Start Address
reservedTopAddress ulong: address Reserved Top

Examples 3
expansionSize ulong: bytes
65536
initialSize ulong: bytes
2555904
minBlockLength ulong: bytes
6
nonNMethodSize ulong: bytes
5839564
nonProfiledSize ulong: bytes
122909338
profiledSize ulong: bytes
122909338
reservedSize ulong: bytes
251658240
reservedTopAddress ulong: address
4806557696
startAddress ulong: address
4554899456
startTime long: millis
285801014750
expansionSize ulong: bytes
65536
initialSize ulong: bytes
2555904
minBlockLength ulong: bytes
6
nonNMethodSize ulong: bytes
5839564
nonProfiledSize ulong: bytes
122909338
profiledSize ulong: bytes
122909338
reservedSize ulong: bytes
251658240
reservedTopAddress ulong: address
4807557120
startAddress ulong: address
4555898880
startTime long: millis
251340778667
expansionSize ulong: bytes
65536
initialSize ulong: bytes
2555904
minBlockLength ulong: bytes
6
nonNMethodSize ulong: bytes
5839564
nonProfiledSize ulong: bytes
122909338
profiledSize ulong: bytes
122909338
reservedSize ulong: bytes
251658240
reservedTopAddress ulong: address
5494538240
startAddress ulong: address
5242880000
startTime long: millis
229552564666

JVM: Code Sweeper

SweepCodeCache

default profiling startTime duration eventThread 11 17 until JDK 20

Category: Java Virtual Machine / Code Sweeper

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/runtime/sweeper.cpp:

  if (_should_sweep) {
    _bytes_changed = 0;
  }

  if (forced) {
    // Notify requester that forced sweep finished
    assert(_force_sweep, "Should be a forced sweep");
    MutexLockerEx mu(CodeCache_lock, Mutex::_no_safepoint_check_flag);
    _force_sweep = false;
    CodeCache_lock->notify();
  }
}

static void post_sweep_event(EventSweepCodeCache* event,
                             const Ticks& start,
                             const Ticks& end,
                             s4 traversals,
                             int swept,
                             int flushed,
                             int zombified) {
  assert(event != NULL, "invariant");
  assert(event->should_commit(), "invariant");
  event->set_starttime(start);
  event->set_endtime(end);
  event->set_sweepId(traversals);

src/hotspot/share/runtime/sweeper.cpp:

  const Ticks sweep_end_counter = Ticks::now();
  const Tickspan sweep_time = sweep_end_counter - sweep_start_counter;
  {
    MutexLockerEx mu(NMethodSweeperStats_lock, Mutex::_no_safepoint_check_flag);
    _total_time_sweeping  += sweep_time;
    _total_time_this_sweep += sweep_time;
    _peak_sweep_fraction_time = MAX2(sweep_time, _peak_sweep_fraction_time);
    _total_flushed_size += freed_memory;
    _total_nof_methods_reclaimed += flushed_count;
    _total_nof_c2_methods_reclaimed += flushed_c2_count;
    _peak_sweep_time = MAX2(_peak_sweep_time, _total_time_this_sweep);
  }

  EventSweepCodeCache event(UNTIMED);
  if (event.should_commit()) {
    post_sweep_event(&event, sweep_start_counter, sweep_end_counter, (s4)_traversals, swept_count, flushed_count, zombified_count);
  }

#ifdef ASSERT
  if(PrintMethodFlushing) {
    tty->print_cr("### sweeper:      sweep time(" JLONG_FORMAT "): ", sweep_time.value());
  }
#endif

  Log(codecache, sweep) log;

Configuration enabled threshold
default true 100 ms
profiling true 100 ms

Field Type Description
sweepId int Sweep Identifier
sweptCount uint Methods Swept
flushedCount uint Methods Flushed
zombifiedCount uint Methods Zombified

CodeSweeperStatistics

default profiling startTime every chunk 11 17 until JDK 20

Category: Java Virtual Machine / Code Sweeper

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/jfr/periodic/jfrPeriodic.cpp:

  event.set_initialSize(InitialCodeCacheSize);
  event.set_reservedSize(ReservedCodeCacheSize);
  event.set_nonNMethodSize(NonNMethodCodeHeapSize);
  event.set_profiledSize(ProfiledCodeHeapSize);
  event.set_nonProfiledSize(NonProfiledCodeHeapSize);
  event.set_expansionSize(CodeCacheExpansionSize);
  event.set_minBlockLength(CodeCacheMinBlockLength);
  event.set_startAddress((u8)CodeCache::low_bound());
  event.set_reservedTopAddress((u8)CodeCache::high_bound());
  event.commit();
}

TRACE_REQUEST_FUNC(CodeSweeperStatistics) {
  EventCodeSweeperStatistics event;
  event.set_sweepCount(NMethodSweeper::traversal_count());
  event.set_methodReclaimedCount(NMethodSweeper::total_nof_methods_reclaimed());
  event.set_totalSweepTime(NMethodSweeper::total_time_sweeping());
  event.set_peakFractionTime(NMethodSweeper::peak_sweep_fraction_time());
  event.set_peakSweepTime(NMethodSweeper::peak_sweep_time());
  event.commit();
}

TRACE_REQUEST_FUNC(CodeSweeperConfiguration) {
  EventCodeSweeperConfiguration event;
  event.set_sweeperEnabled(MethodFlushing);

Configuration enabled period
default true everyChunk
profiling true everyChunk

Field Type Description
sweepCount int Sweeps
methodReclaimedCount int Methods Reclaimed
totalSweepTime Tickspan Time Spent Sweeping
peakFractionTime Tickspan Peak Time Fraction Sweep
peakSweepTime Tickspan Peak Time Full Sweep

CodeSweeperConfiguration

default profiling startTime end of every chunk 11 17 until JDK 20

Category: Java Virtual Machine / Code Sweeper

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/jfr/periodic/jfrPeriodic.cpp:

  event.set_nonProfiledSize(NonProfiledCodeHeapSize);
  event.set_expansionSize(CodeCacheExpansionSize);
  event.set_minBlockLength(CodeCacheMinBlockLength);
  event.set_startAddress((u8)CodeCache::low_bound());
  event.set_reservedTopAddress((u8)CodeCache::high_bound());
  event.commit();
}

TRACE_REQUEST_FUNC(CodeSweeperStatistics) {
  EventCodeSweeperStatistics event;
  event.set_sweepCount(NMethodSweeper::traversal_count());
  event.set_methodReclaimedCount(NMethodSweeper::total_nof_methods_reclaimed());
  event.set_totalSweepTime(NMethodSweeper::total_time_sweeping());
  event.set_peakFractionTime(NMethodSweeper::peak_sweep_fraction_time());
  event.set_peakSweepTime(NMethodSweeper::peak_sweep_time());
  event.commit();
}

TRACE_REQUEST_FUNC(CodeSweeperConfiguration) {
  EventCodeSweeperConfiguration event;
  event.set_sweeperEnabled(MethodFlushing);
  event.set_flushingEnabled(UseCodeCacheFlushing);
  event.commit();
}

Configuration enabled period
default true beginChunk
profiling true beginChunk

Field Type Description
sweeperEnabled boolean Code Sweeper Enabled
flushingEnabled boolean Code Cache Flushing Enabled

JVM: Compiler

Compilation

default profiling startTime duration eventThread 11 17 21 25 26

Category: Java Virtual Machine / Compiler

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/compiler/compileBroker.cpp:

  } else if (AbortVMOnCompilationFailure) {
    if (compilable == ciEnv::MethodCompilable_not_at_tier) {
      fatal("Not compilable at tier %d: %s", task->comp_level(), failure_reason);
    }
    if (compilable == ciEnv::MethodCompilable_never) {
      fatal("Never compilable: %s", failure_reason);
    }
  }
  // simulate crash during compilation
  assert(task->compile_id() != CICrashAt, "just as planned");
}

static void post_compilation_event(EventCompilation* event, CompileTask* task) {
  assert(event != NULL, "invariant");
  assert(event->should_commit(), "invariant");
  event->set_method(task->method());
  event->set_compileId(task->compile_id());
  event->set_compileLevel(task->comp_level());
  event->set_succeded(task->is_success());
  event->set_isOsr(task->osr_bci() != CompileBroker::standard_entry_bci);
  event->set_codeSize((task->code() == NULL) ? 0 : task->code()->total_size());
  event->set_inlinedBytes(task->num_inlined_bytecodes());
  event->commit();
}

src/hotspot/share/compiler/compileBroker.cpp:

  const char* retry_message = NULL;

  int system_dictionary_modification_counter;
  {
    MutexLocker locker(Compile_lock, thread);
    system_dictionary_modification_counter = SystemDictionary::number_of_modifications();
  }

#if INCLUDE_JVMCI
  if (UseJVMCICompiler && comp != NULL && comp->is_jvmci()) {
    JVMCICompiler* jvmci = (JVMCICompiler*) comp;

    TraceTime t1("compilation", &time);
    EventCompilation event;

    // Skip redefined methods
    if (target_handle->is_old()) {
        failure_reason = "redefined method";
        retry_message = "not retryable";
        compilable = ciEnv::MethodCompilable_never;
    } else {
        JVMCIEnv env(task, system_dictionary_modification_counter);
        methodHandle method(thread, target_handle);
        jvmci->compile_method(method, osr_bci, &env);

src/hotspot/share/compiler/compileBroker.cpp:

    assert(thread->env() == &ci_env, "set by ci_env");
    // The thread-env() field is cleared in ~CompileTaskWrapper.

    // Cache Jvmti state
    ci_env.cache_jvmti_state();

    // Cache DTrace flags
    ci_env.cache_dtrace_flags();

    ciMethod* target = ci_env.get_method_from_handle(target_handle);

    TraceTime t1("compilation", &time);
    EventCompilation event;

    if (comp == NULL) {
      ci_env.record_method_not_compilable("no compiler", !TieredCompilation);
    } else {
      if (WhiteBoxAPI && WhiteBox::compilation_locked) {
        MonitorLockerEx locker(Compilation_lock, Mutex::_no_safepoint_check_flag);
        while (WhiteBox::compilation_locked) {
          locker.wait(Mutex::_no_safepoint_check_flag);
        }
      }
      comp->compile_method(&ci_env, target, osr_bci, directive);

src/jdk.internal.vm.ci/share/classes/jdk.vm.ci.hotspot/src/jdk/vm/ci/hotspot/EmptyEventProvider.java:

package jdk.vm.ci.hotspot;

/**
 * An empty implementation for {@link EventProvider}. This implementation is used when no logging is
 * requested.
 */
final class EmptyEventProvider implements EventProvider {

    static InternalError shouldNotReachHere() {
        throw new InternalError("should not reach here");
    }

    @Override
    public CompilationEvent newCompilationEvent() {
        return new EmptyCompilationEvent();
    }

    static class EmptyCompilationEvent implements CompilationEvent {
        @Override
        public void commit() {
            throw shouldNotReachHere();
        }

        @Override
        public boolean shouldWrite() {
            // Events of this class should never been written.
            return false;
        }

src/jdk.internal.vm.ci/share/classes/jdk.vm.ci.hotspot/src/jdk/vm/ci/hotspot/EventProvider.java:

 * Service-provider class for logging compiler related events.
 */
public interface EventProvider {

    /**
     * Creates and returns an empty implementation for {@link EventProvider}. This implementation
     * can be used when no logging is requested.
     */
    static EventProvider createEmptyEventProvider() {
        return new EmptyEventProvider();
    }

    /**
     * Creates and returns an empty implementation for {@link CompilationEvent}.
     */
    static CompilationEvent createEmptyCompilationEvent() {
        return new EmptyCompilationEvent();
    }

    /**
     * Creates and returns an empty implementation for {@link CompilationEvent}.
     */
    static CompilerFailureEvent createEmptyCompilerFailureEvent() {
        return new EmptyCompilerFailureEvent();
    }

    /**
     * An instant event is an event that is not considered to have taken any time.
     */
    public interface InstantEvent {
        /**
         * Commits the event.

src/jdk.internal.vm.ci/share/classes/jdk.vm.ci.hotspot/src/jdk/vm/ci/hotspot/EventProvider.java:

    public interface TimedEvent extends InstantEvent {
        /**
         * Starts the timing for this event.
         */
        void begin();

        /**
         * Ends the timing period for this event.
         */
        void end();
    }

    /**
     * Creates a new {@link CompilationEvent}.
     *
     * @return a compilation event
     */
    CompilationEvent newCompilationEvent();

    /**
     * A compilation event.
     */
    public interface CompilationEvent extends TimedEvent {
        void setMethod(String method);

        void setCompileId(int compileId);

        void setCompileLevel(int compileLevel);

        void setSucceeded(boolean succeeded);

        void setIsOsr(boolean isOsr);

        void setCodeSize(int codeSize);

Configuration enabled threshold
default true 1000 ms
profiling true 100 ms

Field Type Description
method Method Java Method
compileId uint Compilation Identifier
compileLevel ushort Compilation Level
succeded boolean Succeeded
isOsr boolean On Stack Replacement
codeSize ulong: bytes Compiled Code Size
inlinedBytes ulong: bytes Inlined Code Size

Examples 3
codeSize ulong: bytes
6080
compileId uint
98253
compileLevel ushort
4
inlinedBytes ulong: bytes
2170
isOsr boolean
false
method Method
descriptor string
(Ljava/lang/Object;Lorg/apache/spark/util/SizeEstimator$SearchState;)V
hidden boolean
false
modifiers int
2
name string
visitSingleObject
type Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/net
hidden boolean
false
modifiers int
17
name string
org/apache/spark/util/SizeEstimator$
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/net
location string
null
name string
null
version string
null
name string
org/apache/spark/util
startTime long: millis
279104421292
succeded boolean
true
codeSize ulong: bytes
1776
compileId uint
77718
compileLevel ushort
3
inlinedBytes ulong: bytes
40
isOsr boolean
false
method Method
descriptor string
(Ljava/lang/String;Lorg/apache/spark/rpc/netty/InboxMessage;)V
hidden boolean
false
modifiers int
1
name string
post
type Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/net
hidden boolean
false
modifiers int
1
name string
org/apache/spark/rpc/netty/DedicatedMessageLoop
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/net
location string
null
name string
null
version string
null
name string
org/apache/spark/rpc/netty
startTime long: millis
235086116750
succeded boolean
true
codeSize ulong: bytes
28544
compileId uint
115989
compileLevel ushort
4
inlinedBytes ulong: bytes
3106
isOsr boolean
false
method Method
descriptor string
(Lio/netty/util/concurrent/EventExecutorGroup;[Lio/netty/channel/ChannelHandler;)Lio/netty/channel/ChannelPipeline;
hidden boolean
false
modifiers int
145
name string
addLast
type Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/net
hidden boolean
false
modifiers int
1
name string
io/netty/channel/DefaultChannelPipeline
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/net
location string
null
name string
null
version string
null
name string
io/netty/channel
startTime long: millis
249451228250
succeded boolean
true

CompilerPhase

default profiling startTime duration eventThread 11 17 21 25 26

Category: Java Virtual Machine / Compiler

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/opto/compile.hpp:

  Ticks _latest_stage_start_counter;

  void begin_method() {
#ifndef PRODUCT
    if (_printer && _printer->should_print(1)) {
      _printer->begin_method();
    }
#endif
    C->_latest_stage_start_counter.stamp();
  }

  void print_method(CompilerPhaseType cpt, int level = 1) {
    EventCompilerPhase event;
    if (event.should_commit()) {
      event.set_starttime(C->_latest_stage_start_counter);
      event.set_phase((u1) cpt);
      event.set_compileId(C->_compile_id);
      event.set_phaseLevel(level);
      event.commit();
    }


#ifndef PRODUCT
    if (_printer && _printer->should_print(level)) {
      _printer->print_method(CompilerPhaseTypeHelper::to_string(cpt), level);
    }
#endif
    C->_latest_stage_start_counter.stamp();
  }

  void end_method(int level = 1) {
    EventCompilerPhase event;
    if (event.should_commit()) {
      event.set_starttime(C->_latest_stage_start_counter);
      event.set_phase((u1) PHASE_END);
      event.set_compileId(C->_compile_id);
      event.set_phaseLevel(level);
      event.commit();
    }
#ifndef PRODUCT
    if (_printer && _printer->should_print(level)) {
      _printer->end_method();
    }

Configuration enabled threshold
default true 60 s
profiling true 10 s

Field Type Description
phase CompilerPhaseType Compile Phase
compileId uint Compilation Identifier
phaseLevel ushort Phase Level

CompilationFailure

profiling startTime eventThread 11 17 21 25 26

Category: Java Virtual Machine / Compiler

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/ci/ciEnv.cpp:

// ------------------------------------------------------------------
// ciEnv::record_failure()
void ciEnv::record_failure(const char* reason) {
  if (_failure_reason == NULL) {
    // Record the first failure reason.
    _failure_reason = reason;
  }
}

void ciEnv::report_failure(const char* reason) {
  EventCompilationFailure event;
  if (event.should_commit()) {
    event.set_compileId(compile_id());
    event.set_failureMessage(reason);
    event.commit();
  }
}

// ------------------------------------------------------------------
// ciEnv::record_method_not_compilable()
void ciEnv::record_method_not_compilable(const char* reason, bool all_tiers) {
  int new_compilable =

Configuration enabled
default false
profiling true

Field Type Description
failureMessage string Failure Message
compileId uint Compilation Identifier

Examples 3
compileId uint
100561
failureMessage string
concurrent class loading
startTime long: millis
244771713041
compileId uint
102566
failureMessage string
concurrent class loading
startTime long: millis
283875343500
compileId uint
95074
failureMessage string
concurrent class loading
startTime long: millis
263943742792

CompilerInlining

startTime eventThread 11 17 21 25 26

Category: Java Virtual Machine / Compiler / Optimization

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/opto/bytecodeInfo.cpp:

const char* InlineTree::check_can_parse(ciMethod* callee) {
  // Certain methods cannot be parsed at all:
  if ( callee->is_native())                     return "native method";
  if ( callee->is_abstract())                   return "abstract method";
  if (!callee->has_balanced_monitors())         return "not compilable (unbalanced monitors)";
  if ( callee->get_flow_analysis()->failing())  return "not compilable (flow analysis failed)";
  if (!callee->can_be_parsed())                 return "cannot be parsed";
  return NULL;
}

static void post_inlining_event(int compile_id,const char* msg, bool success, int bci, ciMethod* caller, ciMethod* callee) {
  assert(caller != NULL, "invariant");
  assert(callee != NULL, "invariant");
  EventCompilerInlining event;
  if (event.should_commit()) {
    JfrStructCalleeMethod callee_struct;
    callee_struct.set_type(callee->holder()->name()->as_utf8());
    callee_struct.set_name(callee->name()->as_utf8());
    callee_struct.set_descriptor(callee->signature()->as_symbol()->as_utf8());
    event.set_compileId(compile_id);
    event.set_message(msg);
    event.set_succeeded(success);
    event.set_bci(bci);
    event.set_caller(caller->get_Method());
    event.set_callee(callee_struct);

src/hotspot/share/c1/c1_GraphBuilder.cpp:

  Value index = args->at(1);
  if (is_store) {
    Value value = args->at(2);
    Instruction* store = append(new StoreIndexed(array, index, NULL, T_CHAR, value, state_before, false, true));
    store->set_flag(Instruction::NeedsRangeCheckFlag, false);
    _memory->store_value(value);
  } else {
    Instruction* load = append(new LoadIndexed(array, index, NULL, T_CHAR, state_before, true));
    load->set_flag(Instruction::NeedsRangeCheckFlag, false);
    push(load->type(), load);
  }
}

static void post_inlining_event(EventCompilerInlining* event,
                                int compile_id,
                                const char* msg,
                                bool success,
                                int bci,
                                ciMethod* caller,
                                ciMethod* callee) {
  assert(caller != NULL, "invariant");
  assert(callee != NULL, "invariant");
  assert(event != NULL, "invariant");
  assert(event->should_commit(), "invariant");
  JfrStructCalleeMethod callee_struct;

src/hotspot/share/c1/c1_GraphBuilder.cpp:

  if (log != NULL) {
    if (success) {
      if (msg != NULL)
        log->inline_success(msg);
      else
        log->inline_success("receiver is statically known");
    } else {
      if (msg != NULL)
        log->inline_fail(msg);
      else
        log->inline_fail("reason unknown");
    }
  }
  EventCompilerInlining event;
  if (event.should_commit()) {
    post_inlining_event(&event, compilation()->env()->task()->compile_id(), msg, success, bci(), method(), callee);
  }

  CompileTask::print_inlining_ul(callee, scope()->level(), bci(), msg);

  if (!compilation()->directive()->PrintInliningOption) {
    return;
  }
  CompileTask::print_inlining_tty(callee, scope()->level(), bci(), msg);
  if (success && CIPrintMethodCodes) {

Configuration enabled
default false
profiling false

Field Type Description
compileId uint Compilation Identifier
caller Method Caller Method
callee CalleeMethod struct Callee Method
succeeded boolean Succeeded
message string Message
bci int Byte Code Index

Examples 3
bci int
8
callee CalleeMethod
descriptor string
(Ljava/lang/invoke/MethodHandle;Ljava/lang/invoke/MethodType;)Ljava/lang/invoke/MethodHandle;
name string
checkGenericType
type string
java/lang/invoke/Invokers
caller Method
descriptor string
(Ljava/lang/Object;Ljava/lang/Object;)V
hidden boolean
true
modifiers int
8
name string
invoke_MT
type Class
classLoader ClassLoader
null
hidden boolean
true
modifiers int
16
name string
java.lang.invoke.LambdaForm$MH+0x00000070010fc000/1432569632
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/lang/invoke
compileId uint
77457
message string
force inline by annotation
startTime long: millis
230193457708
succeeded boolean
true
bci int
16
callee CalleeMethod
descriptor string
(Lorg/apache/spark/storage/DiskBlockObjectWriter;)V
name string
<init>
type string
org/apache/spark/storage/DiskBlockObjectWriter$$Lambda+0x0000007006616000
caller Method
descriptor string
(Ljava/lang/Object;Ljava/lang/Object;)Ljava/lang/Object;
hidden boolean
true
modifiers int
8
name string
newInvokeSpecial
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
16
name string
java/lang/invoke/DirectMethodHandle$Holder
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/lang/invoke
compileId uint
82514
message string
inline
startTime long: millis
199115266000
succeeded boolean
true
bci int
16
callee CalleeMethod
descriptor string
(Lscala/collection/mutable/HashSet;)V
name string
<init>
type string
org/apache/spark/rdd/RDD$$Lambda+0x0000007006390ee8
caller Method
descriptor string
(Ljava/lang/Object;Ljava/lang/Object;)Ljava/lang/Object;
hidden boolean
true
modifiers int
8
name string
newInvokeSpecial
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
16
name string
java/lang/invoke/DirectMethodHandle$Holder
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/lang/invoke
compileId uint
84079
message string
inline
startTime long: millis
242180618292
succeeded boolean
true

CompilerStatistics

default profiling startTime every chunk 11 17 21 25 26

Category: Java Virtual Machine / Compiler

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/jfr/periodic/jfrPeriodic.cpp:

  void doit() {
    JfrClassLoaderStatsClosure clsc;
    ClassLoaderDataGraph::loaded_cld_do(&clsc);
    clsc.createEvents();
  }
};

TRACE_REQUEST_FUNC(ClassLoaderStatistics) {
  JfrClassLoaderStatsVMOperation op;
  VMThread::execute(&op);
}

TRACE_REQUEST_FUNC(CompilerStatistics) {
  EventCompilerStatistics event;
  event.set_compileCount(CompileBroker::get_total_compile_count());
  event.set_bailoutCount(CompileBroker::get_total_bailout_count());
  event.set_invalidatedCount(CompileBroker::get_total_invalidated_count());
  event.set_osrCompileCount(CompileBroker::get_total_osr_compile_count());
  event.set_standardCompileCount(CompileBroker::get_total_standard_compile_count());
  event.set_osrBytesCompiled(CompileBroker::get_sum_osr_bytes_compiled());
  event.set_standardBytesCompiled(CompileBroker::get_sum_standard_bytes_compiled());
  event.set_nmetodsSize(CompileBroker::get_sum_nmethod_size());
  event.set_nmetodCodeSize(CompileBroker::get_sum_nmethod_code_size());
  event.set_peakTimeSpent(CompileBroker::get_peak_compilation_time());
  event.set_totalTimeSpent(CompileBroker::get_total_compilation_time());

Configuration enabled period
default true 1000 ms
profiling true 1000 ms

Field Type Description
compileCount int Compiled Methods
bailoutCount int Bailouts
invalidatedCount int Invalidated Compilations
osrCompileCount int OSR Compilations
standardCompileCount int Standard Compilations
osrBytesCompiled ulong: bytes OSR Bytes Compiled
standardBytesCompiled ulong: bytes Standard Bytes Compiled
nmetodsSize ulong: bytes until JDK 13 Compilation Resulting Size
nmetodCodeSize ulong: bytes until JDK 13 Compilation Resulting Code Size
peakTimeSpent long: millis Peak Time
totalTimeSpent long: millis Total time

Examples 3
bailoutCount int
15
compileCount int
72656
invalidatedCount int
0
osrBytesCompiled ulong: bytes
0
osrCompileCount int
780
peakTimeSpent long: millis
7513
standardBytesCompiled ulong: bytes
0
standardCompileCount int
71876
startTime long: millis
234019179708
totalTimeSpent long: millis
434061
bailoutCount int
15
compileCount int
92660
invalidatedCount int
0
osrBytesCompiled ulong: bytes
0
osrCompileCount int
1010
peakTimeSpent long: millis
5569
standardBytesCompiled ulong: bytes
0
standardCompileCount int
91650
startTime long: millis
279483659000
totalTimeSpent long: millis
384430
bailoutCount int
12
compileCount int
77630
invalidatedCount int
0
osrBytesCompiled ulong: bytes
0
osrCompileCount int
912
peakTimeSpent long: millis
6943
standardBytesCompiled ulong: bytes
0
standardCompileCount int
76718
startTime long: millis
201508998875
totalTimeSpent long: millis
179624

CompilerConfiguration

default profiling startTime end of every chunk 11 17 21 25 26

Category: Java Virtual Machine / Compiler

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/jfr/periodic/jfrPeriodic.cpp:

  event.set_invalidatedCount(CompileBroker::get_total_invalidated_count());
  event.set_osrCompileCount(CompileBroker::get_total_osr_compile_count());
  event.set_standardCompileCount(CompileBroker::get_total_standard_compile_count());
  event.set_osrBytesCompiled(CompileBroker::get_sum_osr_bytes_compiled());
  event.set_standardBytesCompiled(CompileBroker::get_sum_standard_bytes_compiled());
  event.set_nmetodsSize(CompileBroker::get_sum_nmethod_size());
  event.set_nmetodCodeSize(CompileBroker::get_sum_nmethod_code_size());
  event.set_peakTimeSpent(CompileBroker::get_peak_compilation_time());
  event.set_totalTimeSpent(CompileBroker::get_total_compilation_time());
  event.commit();
}

TRACE_REQUEST_FUNC(CompilerConfiguration) {
  EventCompilerConfiguration event;
  event.set_threadCount(CICompilerCount);
  event.set_tieredCompilation(TieredCompilation);
  event.commit();
}

TRACE_REQUEST_FUNC(CodeCacheStatistics) {
  // Emit stats for all available code heaps
  for (int bt = 0; bt < CodeBlobType::NumTypes; ++bt) {
    if (CodeCache::heap_available(bt)) {
      EventCodeCacheStatistics event;
      event.set_codeBlobType((u1)bt);

Configuration enabled period
default true beginChunk
profiling true beginChunk

Field Type Description
threadCount int Thread Count
tieredCompilation boolean Tiered Compilation

Examples 3
startTime long: millis
266869580708
threadCount int
4
tieredCompilation boolean
true
startTime long: millis
264792425167
threadCount int
4
tieredCompilation boolean
true
startTime long: millis
236110204125
threadCount int
4
tieredCompilation boolean
true

JVM: Flag

IntFlagChanged

default profiling startTime 11 17 21 25 26

Category: Java Virtual Machine / Flag

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/runtime/flags/jvmFlag.cpp:

  if (!result->is_int()) return JVMFlag::WRONG_FORMAT;
  *value = result->get_int();
  return JVMFlag::SUCCESS;
}

JVMFlag::Error JVMFlag::intAtPut(JVMFlag* flag, int* value, JVMFlag::Flags origin) {
  const char* name;
  if (flag == NULL) return JVMFlag::INVALID_FLAG;
  if (!flag->is_int()) return JVMFlag::WRONG_FORMAT;
  name = flag->_name;
  JVMFlag::Error check = apply_constraint_and_check_range_int(name, *value, !JVMFlagConstraintList::validated_after_ergo());
  if (check != JVMFlag::SUCCESS) return check;
  int old_value = flag->get_int();
  trace_flag_changed<EventIntFlagChanged, s4>(name, old_value, *value, origin);
  check = flag->set_int(*value);
  *value = old_value;
  flag->set_origin(origin);
  return check;
}

JVMFlag::Error JVMFlag::intAtPut(const char* name, size_t len, int* value, JVMFlag::Flags origin) {
  JVMFlag* result = JVMFlag::find_flag(name, len);
  return intAtPut(result, value, origin);
}

Configuration enabled
default true
profiling true

Field Type Description
name string Name
oldValue int Old Value
newValue int New Value
origin FlagValueOrigin Origin Consider contributing a description to jfreventcollector.

UnsignedIntFlagChanged

default profiling startTime 11 17 21 25 26

Category: Java Virtual Machine / Flag

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/runtime/flags/jvmFlag.cpp:

  if (!result->is_uint()) return JVMFlag::WRONG_FORMAT;
  *value = result->get_uint();
  return JVMFlag::SUCCESS;
}

JVMFlag::Error JVMFlag::uintAtPut(JVMFlag* flag, uint* value, JVMFlag::Flags origin) {
  const char* name;
  if (flag == NULL) return JVMFlag::INVALID_FLAG;
  if (!flag->is_uint()) return JVMFlag::WRONG_FORMAT;
  name = flag->_name;
  JVMFlag::Error check = apply_constraint_and_check_range_uint(name, *value, !JVMFlagConstraintList::validated_after_ergo());
  if (check != JVMFlag::SUCCESS) return check;
  uint old_value = flag->get_uint();
  trace_flag_changed<EventUnsignedIntFlagChanged, u4>(name, old_value, *value, origin);
  check = flag->set_uint(*value);
  *value = old_value;
  flag->set_origin(origin);
  return check;
}

JVMFlag::Error JVMFlag::uintAtPut(const char* name, size_t len, uint* value, JVMFlag::Flags origin) {
  JVMFlag* result = JVMFlag::find_flag(name, len);
  return uintAtPut(result, value, origin);
}

Configuration enabled
default true
profiling true

Field Type Description
name string Name
oldValue uint Old Value
newValue uint New Value
origin FlagValueOrigin Origin Consider contributing a description to jfreventcollector.

LongFlagChanged

default profiling startTime 11 17 21 25 26

Category: Java Virtual Machine / Flag

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/runtime/flags/jvmFlag.cpp:

JVMFlag::Error JVMFlag::intxAtPut(JVMFlag* flag, intx* value, JVMFlag::Flags origin) {
  const char* name;
  if (flag == NULL) return JVMFlag::INVALID_FLAG;
  if (!flag->is_intx()) return JVMFlag::WRONG_FORMAT;
  name = flag->_name;
  JVMFlag::Error check = apply_constraint_and_check_range_intx(name, *value, !JVMFlagConstraintList::validated_after_ergo());
  if (check != JVMFlag::SUCCESS) return check;
  intx old_value = flag->get_intx();
  trace_flag_changed<EventLongFlagChanged, intx>(name, old_value, *value, origin);
  check = flag->set_intx(*value);
  *value = old_value;
  flag->set_origin(origin);
  return check;
}

JVMFlag::Error JVMFlag::intxAtPut(const char* name, size_t len, intx* value, JVMFlag::Flags origin) {
  JVMFlag* result = JVMFlag::find_flag(name, len);
  return intxAtPut(result, value, origin);
}

Configuration enabled
default true
profiling true

Field Type Description
name string Name
oldValue long Old Value
newValue long New Value
origin FlagValueOrigin Origin Consider contributing a description to jfreventcollector.

UnsignedLongFlagChanged

default profiling startTime 11 17 21 25 26

Category: Java Virtual Machine / Flag

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/runtime/flags/jvmFlag.cpp:

JVMFlag::Error JVMFlag::uintxAtPut(JVMFlag* flag, uintx* value, JVMFlag::Flags origin) {
  const char* name;
  if (flag == NULL) return JVMFlag::INVALID_FLAG;
  if (!flag->is_uintx()) return JVMFlag::WRONG_FORMAT;
  name = flag->_name;
  JVMFlag::Error check = apply_constraint_and_check_range_uintx(name, *value, !JVMFlagConstraintList::validated_after_ergo());
  if (check != JVMFlag::SUCCESS) return check;
  uintx old_value = flag->get_uintx();
  trace_flag_changed<EventUnsignedLongFlagChanged, u8>(name, old_value, *value, origin);
  check = flag->set_uintx(*value);
  *value = old_value;
  flag->set_origin(origin);
  return check;
}

JVMFlag::Error JVMFlag::uintxAtPut(const char* name, size_t len, uintx* value, JVMFlag::Flags origin) {
  JVMFlag* result = JVMFlag::find_flag(name, len);
  return uintxAtPut(result, value, origin);
}

src/hotspot/share/runtime/flags/jvmFlag.cpp:

JVMFlag::Error JVMFlag::uint64_tAtPut(JVMFlag* flag, uint64_t* value, JVMFlag::Flags origin) {
  const char* name;
  if (flag == NULL) return JVMFlag::INVALID_FLAG;
  if (!flag->is_uint64_t()) return JVMFlag::WRONG_FORMAT;
  name = flag->_name;
  JVMFlag::Error check = apply_constraint_and_check_range_uint64_t(name, *value, !JVMFlagConstraintList::validated_after_ergo());
  if (check != JVMFlag::SUCCESS) return check;
  uint64_t old_value = flag->get_uint64_t();
  trace_flag_changed<EventUnsignedLongFlagChanged, u8>(name, old_value, *value, origin);
  check = flag->set_uint64_t(*value);
  *value = old_value;
  flag->set_origin(origin);
  return check;
}

JVMFlag::Error JVMFlag::uint64_tAtPut(const char* name, size_t len, uint64_t* value, JVMFlag::Flags origin) {
  JVMFlag* result = JVMFlag::find_flag(name, len);
  return uint64_tAtPut(result, value, origin);
}

src/hotspot/share/runtime/flags/jvmFlag.cpp:

JVMFlag::Error JVMFlag::size_tAtPut(JVMFlag* flag, size_t* value, JVMFlag::Flags origin) {
  const char* name;
  if (flag == NULL) return JVMFlag::INVALID_FLAG;
  if (!flag->is_size_t()) return JVMFlag::WRONG_FORMAT;
  name = flag->_name;
  JVMFlag::Error check = apply_constraint_and_check_range_size_t(name, *value, !JVMFlagConstraintList::validated_after_ergo());
  if (check != JVMFlag::SUCCESS) return check;
  size_t old_value = flag->get_size_t();
  trace_flag_changed<EventUnsignedLongFlagChanged, u8>(name, old_value, *value, origin);
  check = flag->set_size_t(*value);
  *value = old_value;
  flag->set_origin(origin);
  return check;
}

JVMFlag::Error JVMFlag::size_tAtPut(const char* name, size_t len, size_t* value, JVMFlag::Flags origin) {
  JVMFlag* result = JVMFlag::find_flag(name, len);
  return size_tAtPut(result, value, origin);
}

Configuration enabled
default true
profiling true

Field Type Description
name string Name
oldValue ulong Old Value
newValue ulong New Value
origin FlagValueOrigin Origin Consider contributing a description to jfreventcollector.

DoubleFlagChanged

default profiling startTime 11 17 21 25 26

Category: Java Virtual Machine / Flag

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/runtime/flags/jvmFlag.cpp:

JVMFlag::Error JVMFlag::doubleAtPut(JVMFlag* flag, double* value, JVMFlag::Flags origin) {
  const char* name;
  if (flag == NULL) return JVMFlag::INVALID_FLAG;
  if (!flag->is_double()) return JVMFlag::WRONG_FORMAT;
  name = flag->_name;
  JVMFlag::Error check = apply_constraint_and_check_range_double(name, *value, !JVMFlagConstraintList::validated_after_ergo());
  if (check != JVMFlag::SUCCESS) return check;
  double old_value = flag->get_double();
  trace_flag_changed<EventDoubleFlagChanged, double>(name, old_value, *value, origin);
  check = flag->set_double(*value);
  *value = old_value;
  flag->set_origin(origin);
  return check;
}

JVMFlag::Error JVMFlag::doubleAtPut(const char* name, size_t len, double* value, JVMFlag::Flags origin) {
  JVMFlag* result = JVMFlag::find_flag(name, len);
  return doubleAtPut(result, value, origin);
}

Configuration enabled
default true
profiling true

Field Type Description
name string Name
oldValue double Old Value
newValue double New Value
origin FlagValueOrigin Origin Consider contributing a description to jfreventcollector.

BooleanFlagChanged

default profiling startTime 11 17 21 25 26

Category: Java Virtual Machine / Flag

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/runtime/flags/jvmFlag.cpp:

  if (!result->is_bool()) return JVMFlag::WRONG_FORMAT;
  *value = result->get_bool();
  return JVMFlag::SUCCESS;
}

JVMFlag::Error JVMFlag::boolAtPut(JVMFlag* flag, bool* value, JVMFlag::Flags origin) {
  const char* name;
  if (flag == NULL) return JVMFlag::INVALID_FLAG;
  if (!flag->is_bool()) return JVMFlag::WRONG_FORMAT;
  name = flag->_name;
  JVMFlag::Error check = apply_constraint_and_check_range_bool(name, *value, !JVMFlagConstraintList::validated_after_ergo());
  if (check != JVMFlag::SUCCESS) return check;
  bool old_value = flag->get_bool();
  trace_flag_changed<EventBooleanFlagChanged, bool>(name, old_value, *value, origin);
  check = flag->set_bool(*value);
  *value = old_value;
  flag->set_origin(origin);
  return check;
}

JVMFlag::Error JVMFlag::boolAtPut(const char* name, size_t len, bool* value, JVMFlag::Flags origin) {
  JVMFlag* result = JVMFlag::find_flag(name, len);
  return boolAtPut(result, value, origin);
}

Configuration enabled
default true
profiling true

Field Type Description
name string Name
oldValue boolean Old Value
newValue boolean New Value
origin FlagValueOrigin Origin Consider contributing a description to jfreventcollector.

StringFlagChanged

default profiling startTime 11 17 21 25 26

Category: Java Virtual Machine / Flag

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/runtime/flags/jvmFlag.cpp:

JVMFlag::Error JVMFlag::ccstrAt(const char* name, size_t len, ccstr* value, bool allow_locked, bool return_flag) {
  JVMFlag* result = JVMFlag::find_flag(name, len, allow_locked, return_flag);
  if (result == NULL) return JVMFlag::INVALID_FLAG;
  if (!result->is_ccstr()) return JVMFlag::WRONG_FORMAT;
  *value = result->get_ccstr();
  return JVMFlag::SUCCESS;
}

JVMFlag::Error JVMFlag::ccstrAtPut(const char* name, size_t len, ccstr* value, JVMFlag::Flags origin) {
  JVMFlag* result = JVMFlag::find_flag(name, len);
  if (result == NULL) return JVMFlag::INVALID_FLAG;
  if (!result->is_ccstr()) return JVMFlag::WRONG_FORMAT;
  ccstr old_value = result->get_ccstr();
  trace_flag_changed<EventStringFlagChanged, const char*>(name, old_value, *value, origin);
  char* new_value = NULL;
  if (*value != NULL) {
    new_value = os::strdup_check_oom(*value);
  }
  JVMFlag::Error check = result->set_ccstr(new_value);
  if (result->is_default() && old_value != NULL) {
    // Prior value is NOT heap allocated, but was a literal constant.
    old_value = os::strdup_check_oom(old_value);
  }
  *value = old_value;
  result->set_origin(origin);
  return check;
}

JVMFlag::Error JVMFlagEx::ccstrAtPut(JVMFlagsWithType flag, ccstr value, JVMFlag::Flags origin) {
  JVMFlag* faddr = address_of_flag(flag);
  guarantee(faddr != NULL && faddr->is_ccstr(), "wrong flag type");
  ccstr old_value = faddr->get_ccstr();
  trace_flag_changed<EventStringFlagChanged, const char*>(faddr->_name, old_value, value, origin);
  char* new_value = os::strdup_check_oom(value);
  JVMFlag::Error check = faddr->set_ccstr(new_value);
  if (!faddr->is_default() && old_value != NULL) {
    // Prior value is heap allocated so free it.
    FREE_C_HEAP_ARRAY(char, old_value);
  }
  faddr->set_origin(origin);
  return check;
}

extern "C" {

Configuration enabled
default true
profiling true

Field Type Description
name string Name
oldValue string Old Value
newValue string New Value
origin FlagValueOrigin Origin Consider contributing a description to jfreventcollector.

IntFlag

default profiling startTime duration end of every chunk 11 17 21 25 26

Category: Java Virtual Machine / Flag

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Configuration enabled period
default true beginChunk
profiling true beginChunk

Field Type Description
name string Name
value int Value
origin FlagValueOrigin Origin Consider contributing a description to jfreventcollector.

Examples 3
name string
JavaPriority9_To_OSPriority
origin FlagValueOrigin
Default
startTime long: millis
233971205458
value int
-1
name string
SoftwarePrefetchHintDistance
origin FlagValueOrigin
Default
startTime long: millis
201472541458
value int
384
name string
PerfMaxStringConstLength
origin FlagValueOrigin
Default
startTime long: millis
247327046958
value int
1024

UnsignedIntFlag

default profiling startTime duration end of every chunk 11 17 21 25 26

Category: Java Virtual Machine / Flag

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Configuration enabled period
default true beginChunk
profiling true beginChunk

Field Type Description
name string Name
value uint Value
origin FlagValueOrigin Origin Consider contributing a description to jfreventcollector.

Examples 3
name string
ConcGCThreads
origin FlagValueOrigin
Ergonomic
startTime long: millis
218782430833
value uint
3
name string
GCCardSizeInBytes
origin FlagValueOrigin
Default
startTime long: millis
243545631042
value uint
512
name string
TestCrashInErrorHandler
origin FlagValueOrigin
Default
startTime long: millis
242226847208
value uint
0

LongFlag

default profiling startTime duration end of every chunk 11 17 21 25 26

Category: Java Virtual Machine / Flag

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Configuration enabled period
default true beginChunk
profiling true beginChunk

Field Type Description
name string Name
value long Value
origin FlagValueOrigin Origin Consider contributing a description to jfreventcollector.

Examples 3
name string
Tier3InvocationThreshold
origin FlagValueOrigin
Default
startTime long: millis
242226861000
value long
200
name string
NMethodSizeLimit
origin FlagValueOrigin
Default
startTime long: millis
199126999666
value long
524288
name string
Tier4InvocationThreshold
origin FlagValueOrigin
Default
startTime long: millis
230210328500
value long
5000

UnsignedLongFlag

default profiling startTime duration end of every chunk 11 17 21 25 26

Category: Java Virtual Machine / Flag

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Configuration enabled period
default true beginChunk
profiling true beginChunk

Field Type Description
name string Name
value ulong Value
origin FlagValueOrigin Origin Consider contributing a description to jfreventcollector.

Examples 3
name string
MaxGCMinorPauseMillis
origin FlagValueOrigin
Default
startTime long: millis
230210338208
value ulong
-1
name string
MaxMetaspaceFreeRatio
origin FlagValueOrigin
Default
startTime long: millis
199127010875
value ulong
70
name string
YoungGenerationSizeIncrement
origin FlagValueOrigin
Default
startTime long: millis
242226879625
value ulong
20

DoubleFlag

default profiling startTime duration end of every chunk 11 17 21 25 26

Category: Java Virtual Machine / Flag

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Configuration enabled period
default true beginChunk
profiling true beginChunk

Field Type Description
name string Name
value double Value
origin FlagValueOrigin Origin Consider contributing a description to jfreventcollector.

Examples 3
name string
ZAllocationSpikeTolerance
origin FlagValueOrigin
Default
startTime long: millis
243545654875
value double
2.0
name string
CompileThresholdScaling
origin FlagValueOrigin
Default
startTime long: millis
252333721542
value double
1.0
name string
MinRAMPercentage
origin FlagValueOrigin
Default
startTime long: millis
201472570708
value double
50.0

BooleanFlag

default profiling startTime duration end of every chunk 11 17 21 25 26

Category: Java Virtual Machine / Flag

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Configuration enabled period
default true beginChunk
profiling true beginChunk

Field Type Description
name string Name
value boolean Value
origin FlagValueOrigin Origin Consider contributing a description to jfreventcollector.

Examples 3
name string
VerifyCodeCache
origin FlagValueOrigin
Default
startTime long: millis
242226920333
value boolean
false
name string
C1UpdateMethodData
origin FlagValueOrigin
Default
startTime long: millis
199127027083
value boolean
true
name string
AutoCreateSharedArchive
origin FlagValueOrigin
Default
startTime long: millis
230210346417
value boolean
false

StringFlag

default profiling startTime duration end of every chunk 11 17 21 25 26

Category: Java Virtual Machine / Flag

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Configuration enabled period
default true beginChunk
profiling true beginChunk

Field Type Description
name string Name
value string Value
origin FlagValueOrigin Origin Consider contributing a description to jfreventcollector.

Examples 3
name string
PrintIdealGraphFile
origin FlagValueOrigin
Default
startTime long: millis
212458737250
value string
null
name string
InlineDataFile
origin FlagValueOrigin
Default
startTime long: millis
233971259167
value string
null
name string
OnError
origin FlagValueOrigin
Default
startTime long: millis
252333779500
value string

JVM: GC: Collector

GarbageCollection

default profiling startTime duration 11 17 21 25 26

Category: Java Virtual Machine / GC / Collector

Garbage collection performed by the JVM

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/gc/shared/gcTraceSend.cpp:

#if INCLUDE_G1GC
#include "gc/g1/evacuationInfo.hpp"
#include "gc/g1/g1YCTypes.hpp"
#endif

// All GC dependencies against the trace framework is contained within this file.

typedef uintptr_t TraceAddress;

void GCTracer::send_garbage_collection_event() const {
  EventGarbageCollection event(UNTIMED);
  if (event.should_commit()) {
    event.set_gcId(GCId::current());
    event.set_name(_shared_gc_info.name());
    event.set_cause((u2) _shared_gc_info.cause());
    event.set_sumOfPauses(_shared_gc_info.sum_of_pauses());
    event.set_longestPause(_shared_gc_info.longest_pause());
    event.set_starttime(_shared_gc_info.start_timestamp());
    event.set_endtime(_shared_gc_info.end_timestamp());
    event.commit();
  }
}

Configuration enabled threshold
default true 0 ms
profiling true 0 ms

Field Type Description
gcId uint GC Identifier
name GCName Name The name of the Garbage Collector
cause GCCause Cause The reason for triggering this Garbage Collection
sumOfPauses Tickspan Sum of Pauses Sum of all the times in which Java execution was paused during the garbage collection
longestPause Tickspan Longest Pause Longest individual pause during the garbage collection

Examples 3
cause GCCause
System.gc()
gcId uint
332
longestPause Tickspan
56905792
name GCName
ParallelOld
startTime long: millis
252957973833
sumOfPauses Tickspan
56905792
cause GCCause
Allocation Failure
gcId uint
765
longestPause Tickspan
2839458
name GCName
DefNew
startTime long: millis
273837134292
sumOfPauses Tickspan
2839458
cause GCCause
Heap Inspection Initiated GC
gcId uint
783
longestPause Tickspan
34701875
name GCName
G1Full
startTime long: millis
200101714166
sumOfPauses Tickspan
34701875

ParallelOldGarbageCollection

default profiling startTime duration 11 17 21 25 26

Category: Java Virtual Machine / GC / Collector

Appearing in: ParallelGC

Missing in: G1GC, SerialGC, ShenandoahGC, ZGC

Extra information specific to Parallel Old Garbage Collections

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/gc/shared/gcTraceSend.cpp:

    e.set_smallChunksTotalSize(summary.small_chunks_size_in_bytes());

    e.set_mediumChunks(summary.num_medium_chunks());
    e.set_mediumChunksTotalSize(summary.medium_chunks_size_in_bytes());

    e.set_humongousChunks(summary.num_humongous_chunks());
    e.set_humongousChunksTotalSize(summary.humongous_chunks_size_in_bytes());

    e.commit();
  }
}

void ParallelOldTracer::send_parallel_old_event() const {
  EventParallelOldGarbageCollection e(UNTIMED);
  if (e.should_commit()) {
    e.set_gcId(GCId::current());
    e.set_densePrefix((TraceAddress)_parallel_old_gc_info.dense_prefix());
    e.set_starttime(_shared_gc_info.start_timestamp());
    e.set_endtime(_shared_gc_info.end_timestamp());
    e.commit();
  }
}

void YoungGCTracer::send_young_gc_event() const {
  EventYoungGarbageCollection e(UNTIMED);

Configuration enabled threshold
default true 0 ms
profiling true 0 ms

Field Type Description
gcId uint GC Identifier
densePrefix ulong: address Dense Prefix The address of the dense prefix, used when compacting

Examples 1
densePrefix ulong: address
21722300416
gcId uint
363
startTime long: millis
265637685292

YoungGarbageCollection

default profiling startTime duration 11 17 21 25 26

Category: Java Virtual Machine / GC / Collector

Appearing in: G1GC, ParallelGC, SerialGC

Missing in: ShenandoahGC, ZGC

Extra information specific to Young Garbage Collections

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/gc/shared/gcTraceSend.cpp:

void ParallelOldTracer::send_parallel_old_event() const {
  EventParallelOldGarbageCollection e(UNTIMED);
  if (e.should_commit()) {
    e.set_gcId(GCId::current());
    e.set_densePrefix((TraceAddress)_parallel_old_gc_info.dense_prefix());
    e.set_starttime(_shared_gc_info.start_timestamp());
    e.set_endtime(_shared_gc_info.end_timestamp());
    e.commit();
  }
}

void YoungGCTracer::send_young_gc_event() const {
  EventYoungGarbageCollection e(UNTIMED);
  if (e.should_commit()) {
    e.set_gcId(GCId::current());
    e.set_tenuringThreshold(_tenuring_threshold);
    e.set_starttime(_shared_gc_info.start_timestamp());
    e.set_endtime(_shared_gc_info.end_timestamp());
    e.commit();
  }
}

bool YoungGCTracer::should_send_promotion_in_new_plab_event() const {
  return EventPromoteObjectInNewPLAB::is_enabled();

Configuration enabled threshold
default true 0 ms
profiling true 0 ms

Field Type Description
gcId uint GC Identifier
tenuringThreshold uint Tenuring Threshold

Examples 3
gcId uint
753
startTime long: millis
270545344792
tenuringThreshold uint
15
gcId uint
322
startTime long: millis
246390892500
tenuringThreshold uint
1
gcId uint
810
startTime long: millis
224323825833
tenuringThreshold uint
15

OldGarbageCollection

default profiling startTime duration 11 17 21 25 26

Category: Java Virtual Machine / GC / Collector

Appearing in: G1GC, ParallelGC, SerialGC

Missing in: ShenandoahGC, ZGC

Extra information specific to Old Garbage Collections

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/gc/shared/gcTraceSend.cpp:

  EventPromoteObjectOutsidePLAB event;
  if (event.should_commit()) {
    event.set_gcId(GCId::current());
    event.set_objectClass(klass);
    event.set_objectSize(obj_size);
    event.set_tenured(tenured);
    event.set_tenuringAge(age);
    event.commit();
  }
}

void OldGCTracer::send_old_gc_event() const {
  EventOldGarbageCollection e(UNTIMED);
  if (e.should_commit()) {
    e.set_gcId(GCId::current());
    e.set_starttime(_shared_gc_info.start_timestamp());
    e.set_endtime(_shared_gc_info.end_timestamp());
    e.commit();
  }
}

static JfrStructCopyFailed to_struct(const CopyFailedInfo& cf_info) {
  JfrStructCopyFailed failed_info;
  failed_info.set_objectCount(cf_info.failed_count());

Configuration enabled threshold
default true 0 ms
profiling true 0 ms

Field Type Description
gcId uint GC Identifier

Examples 3
gcId uint
318
startTime long: millis
243546559917
gcId uint
743
startTime long: millis
267187034750
gcId uint
830
startTime long: millis
226657292916

G1GarbageCollection

default profiling startTime duration 11 17 21 25 26

Category: Java Virtual Machine / GC / Collector

Appearing in: G1GC

Missing in: ParallelGC, SerialGC, ShenandoahGC, ZGC

Extra information specific to G1 Garbage Collections

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/gc/shared/gcTraceSend.cpp:

// Common to CMS and G1
void OldGCTracer::send_concurrent_mode_failure_event() {
  EventConcurrentModeFailure e;
  if (e.should_commit()) {
    e.set_gcId(GCId::current());
    e.commit();
  }
}

#if INCLUDE_G1GC
void G1NewTracer::send_g1_young_gc_event() {
  EventG1GarbageCollection e(UNTIMED);
  if (e.should_commit()) {
    e.set_gcId(GCId::current());
    e.set_type(_g1_young_gc_info.type());
    e.set_starttime(_shared_gc_info.start_timestamp());
    e.set_endtime(_shared_gc_info.end_timestamp());
    e.commit();
  }
}

void G1MMUTracer::send_g1_mmu_event(double time_slice_ms, double gc_time_ms, double max_time_ms) {
  EventG1MMU e;

Configuration enabled threshold
default true 0 ms
profiling true 0 ms

Field Type Description
gcId uint GC Identifier
type G1YCType Type Consider contributing a description to jfreventcollector.

Examples 1
gcId uint
890
startTime long: millis
242791185416
type G1YCType
Mixed

JVM: GC: Configuration

GCConfiguration

default profiling startTime duration end of every chunk 11 17 21 25 26

Category: Java Virtual Machine / GC / Configuration

The configuration of the garbage collector

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/jfr/periodic/jfrPeriodic.cpp:

  if (UseG1GC) {
    VM_G1SendHeapRegionInfoEvents op;
    VMThread::execute(&op);
  }
}

// Java Mission Control (JMC) uses (Java) Long.MIN_VALUE to describe that a
// long value is undefined.
static jlong jmc_undefined_long = min_jlong;

TRACE_REQUEST_FUNC(GCConfiguration) {
  GCConfiguration conf;
  jlong pause_target = conf.has_pause_target_default_value() ? jmc_undefined_long : conf.pause_target();
  EventGCConfiguration event;
  event.set_youngCollector(conf.young_collector());
  event.set_oldCollector(conf.old_collector());
  event.set_parallelGCThreads(conf.num_parallel_gc_threads());
  event.set_concurrentGCThreads(conf.num_concurrent_gc_threads());
  event.set_usesDynamicGCThreads(conf.uses_dynamic_gc_threads());
  event.set_isExplicitGCConcurrent(conf.is_explicit_gc_concurrent());
  event.set_isExplicitGCDisabled(conf.is_explicit_gc_disabled());
  event.set_gcTimeRatio(conf.gc_time_ratio());
  event.set_pauseTarget((s8)pause_target);
  event.commit();
}

Configuration enabled period
default true everyChunk
profiling true everyChunk

Field Type Description
youngCollector GCName Young Garbage Collector The garbage collector used for the young generation
oldCollector GCName Old Garbage Collector The garbage collector used for the old generation
parallelGCThreads uint Parallel GC Threads Number of parallel threads to use for garbage collection
concurrentGCThreads uint Concurrent GC Threads Number of concurrent threads to use for garbage collection
usesDynamicGCThreads boolean Uses Dynamic GC Threads Whether a dynamic number of GC threads are used or not
isExplicitGCConcurrent boolean Concurrent Explicit GC Whether System.gc() is concurrent or not
isExplicitGCDisabled boolean Disabled Explicit GC Whether System.gc() will cause a garbage collection or not
pauseTarget long: millis Pause Target Target for GC pauses
gcTimeRatio uint GC Time Ratio Target for runtime vs garbage collection time

Examples 3
concurrentGCThreads uint
0
gcTimeRatio uint
99
isExplicitGCConcurrent boolean
false
isExplicitGCDisabled boolean
false
oldCollector GCName
SerialOld
parallelGCThreads uint
0
pauseTarget long: millis
-9223372036854775808
startTime long: millis
261258682542
usesDynamicGCThreads boolean
true
youngCollector GCName
DefNew
concurrentGCThreads uint
3
gcTimeRatio uint
12
isExplicitGCConcurrent boolean
false
isExplicitGCDisabled boolean
false
oldCollector GCName
G1Old
parallelGCThreads uint
10
pauseTarget long: millis
-9223372036854775808
startTime long: millis
235879506833
usesDynamicGCThreads boolean
true
youngCollector GCName
G1New
concurrentGCThreads uint
0
gcTimeRatio uint
99
isExplicitGCConcurrent boolean
false
isExplicitGCDisabled boolean
false
oldCollector GCName
ParallelOld
parallelGCThreads uint
10
pauseTarget long: millis
-9223372036854775808
startTime long: millis
230258099000
usesDynamicGCThreads boolean
true
youngCollector GCName
ParallelScavenge

GCSurvivorConfiguration

default profiling startTime duration end of every chunk 11 17 21 25 26

Category: Java Virtual Machine / GC / Configuration

The configuration of the survivors of garbage collection

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/jfr/periodic/jfrPeriodic.cpp:

TRACE_REQUEST_FUNC(GCTLABConfiguration) {
  GCTLABConfiguration conf;
  EventGCTLABConfiguration event;
  event.set_usesTLABs(conf.uses_tlabs());
  event.set_minTLABSize(conf.min_tlab_size());
  event.set_tlabRefillWasteLimit(conf.tlab_refill_waste_limit());
  event.commit();
}

TRACE_REQUEST_FUNC(GCSurvivorConfiguration) {
  GCSurvivorConfiguration conf;
  EventGCSurvivorConfiguration event;
  event.set_maxTenuringThreshold(conf.max_tenuring_threshold());
  event.set_initialTenuringThreshold(conf.initial_tenuring_threshold());
  event.commit();
}

TRACE_REQUEST_FUNC(GCHeapConfiguration) {
  GCHeapConfiguration conf;
  EventGCHeapConfiguration event;
  event.set_minSize(conf.min_size());
  event.set_maxSize(conf.max_size());
  event.set_initialSize(conf.initial_size());

Configuration enabled period
default true beginChunk
profiling true beginChunk

Field Type Description
maxTenuringThreshold ubyte Maximum Tenuring Threshold Upper limit for the age of how old objects to keep in the survivor area
initialTenuringThreshold ubyte Initial Tenuring Threshold Initial age limit for how old objects to keep in survivor area

Examples 3
initialTenuringThreshold ubyte
7
maxTenuringThreshold ubyte
15
startTime long: millis
258589109000
initialTenuringThreshold ubyte
7
maxTenuringThreshold ubyte
15
startTime long: millis
236152301458
initialTenuringThreshold ubyte
7
maxTenuringThreshold ubyte
15
startTime long: millis
260779019875

GCTLABConfiguration

default profiling startTime duration end of every chunk 11 17 21 25 26

Category: Java Virtual Machine / GC / Configuration

The configuration of the Thread Local Allocation Buffers (TLABs)

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/jfr/periodic/jfrPeriodic.cpp:

  event.set_oldCollector(conf.old_collector());
  event.set_parallelGCThreads(conf.num_parallel_gc_threads());
  event.set_concurrentGCThreads(conf.num_concurrent_gc_threads());
  event.set_usesDynamicGCThreads(conf.uses_dynamic_gc_threads());
  event.set_isExplicitGCConcurrent(conf.is_explicit_gc_concurrent());
  event.set_isExplicitGCDisabled(conf.is_explicit_gc_disabled());
  event.set_gcTimeRatio(conf.gc_time_ratio());
  event.set_pauseTarget((s8)pause_target);
  event.commit();
}

TRACE_REQUEST_FUNC(GCTLABConfiguration) {
  GCTLABConfiguration conf;
  EventGCTLABConfiguration event;
  event.set_usesTLABs(conf.uses_tlabs());
  event.set_minTLABSize(conf.min_tlab_size());
  event.set_tlabRefillWasteLimit(conf.tlab_refill_waste_limit());
  event.commit();
}

TRACE_REQUEST_FUNC(GCSurvivorConfiguration) {
  GCSurvivorConfiguration conf;
  EventGCSurvivorConfiguration event;
  event.set_maxTenuringThreshold(conf.max_tenuring_threshold());
  event.set_initialTenuringThreshold(conf.initial_tenuring_threshold());

Configuration enabled period
default true beginChunk
profiling true beginChunk

Field Type Description
usesTLABs boolean TLABs Used If Thread Local Allocation Buffers (TLABs) are in use
minTLABSize ulong: bytes Minimum TLAB Size
tlabRefillWasteLimit ulong: bytes TLAB Refill Waste Limit

Examples 3
minTLABSize ulong: bytes
2048
startTime long: millis
242261937583
tlabRefillWasteLimit ulong: bytes
64
usesTLABs boolean
true
minTLABSize ulong: bytes
2048
startTime long: millis
206020035833
tlabRefillWasteLimit ulong: bytes
64
usesTLABs boolean
true
minTLABSize ulong: bytes
2048
startTime long: millis
279483553917
tlabRefillWasteLimit ulong: bytes
64
usesTLABs boolean
true

GCHeapConfiguration

default profiling startTime duration end of every chunk 11 17 21 25 26

Category: Java Virtual Machine / GC / Configuration

The configuration of the garbage collected heap

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/jfr/periodic/jfrPeriodic.cpp:

  event.commit();
}

TRACE_REQUEST_FUNC(GCSurvivorConfiguration) {
  GCSurvivorConfiguration conf;
  EventGCSurvivorConfiguration event;
  event.set_maxTenuringThreshold(conf.max_tenuring_threshold());
  event.set_initialTenuringThreshold(conf.initial_tenuring_threshold());
  event.commit();
}

TRACE_REQUEST_FUNC(GCHeapConfiguration) {
  GCHeapConfiguration conf;
  EventGCHeapConfiguration event;
  event.set_minSize(conf.min_size());
  event.set_maxSize(conf.max_size());
  event.set_initialSize(conf.initial_size());
  event.set_usesCompressedOops(conf.uses_compressed_oops());
  event.set_compressedOopsMode(conf.narrow_oop_mode());
  event.set_objectAlignment(conf.object_alignment_in_bytes());
  event.set_heapAddressBits(conf.heap_address_size_in_bits());
  event.commit();
}

TRACE_REQUEST_FUNC(YoungGenerationConfiguration) {

Configuration enabled period
default true beginChunk
profiling true beginChunk

Field Type Description
minSize ulong: bytes Minimum Heap Size
maxSize ulong: bytes Maximum Heap Size
initialSize ulong: bytes Initial Heap Size
usesCompressedOops boolean If Compressed Oops Are Used If compressed Oops (Ordinary Object Pointers) are enabled
compressedOopsMode NarrowOopMode Compressed Oops Mode The kind of compressed oops being used
objectAlignment ulong: bytes Object Alignment Object alignment (in bytes) on the heap
heapAddressBits ubyte Heap Address Size Heap Address Size (in bits)

Examples 3
compressedOopsMode NarrowOopMode
Zero based
heapAddressBits ubyte
32
initialSize ulong: bytes
805306368
maxSize ulong: bytes
12884901888
minSize ulong: bytes
8388608
objectAlignment ulong: bytes
8
startTime long: millis
251392920333
usesCompressedOops boolean
true
compressedOopsMode NarrowOopMode
Zero based
heapAddressBits ubyte
32
initialSize ulong: bytes
805306368
maxSize ulong: bytes
12884901888
minSize ulong: bytes
8388608
objectAlignment ulong: bytes
8
startTime long: millis
276149849625
usesCompressedOops boolean
true
compressedOopsMode NarrowOopMode
Zero based
heapAddressBits ubyte
32
initialSize ulong: bytes
805306368
maxSize ulong: bytes
12884901888
minSize ulong: bytes
8388608
objectAlignment ulong: bytes
8
startTime long: millis
240062879666
usesCompressedOops boolean
true

YoungGenerationConfiguration

default profiling startTime duration end of every chunk 11 17 21 25 26

Category: Java Virtual Machine / GC / Configuration

The configuration of the young generation of the garbage collected heap

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/jfr/periodic/jfrPeriodic.cpp:

  event.set_minSize(conf.min_size());
  event.set_maxSize(conf.max_size());
  event.set_initialSize(conf.initial_size());
  event.set_usesCompressedOops(conf.uses_compressed_oops());
  event.set_compressedOopsMode(conf.narrow_oop_mode());
  event.set_objectAlignment(conf.object_alignment_in_bytes());
  event.set_heapAddressBits(conf.heap_address_size_in_bits());
  event.commit();
}

TRACE_REQUEST_FUNC(YoungGenerationConfiguration) {
  GCYoungGenerationConfiguration conf;
  jlong max_size = conf.has_max_size_default_value() ? jmc_undefined_long : conf.max_size();
  EventYoungGenerationConfiguration event;
  event.set_maxSize((u8)max_size);
  event.set_minSize(conf.min_size());
  event.set_newRatio(conf.new_ratio());
  event.commit();
}

TRACE_REQUEST_FUNC(InitialSystemProperty) {
  SystemProperty* p = Arguments::system_properties();
  JfrTicks time_stamp = JfrTicks::now();
  while (p !=  NULL) {
    if (!p->internal()) {

Configuration enabled period
default true beginChunk
profiling true beginChunk

Field Type Description
minSize ulong: bytes Minimum Young Generation Size
maxSize ulong: bytes Maximum Young Generation Size
newRatio uint New Ratio The size of the young generation relative to the tenured generation

Examples 3
maxSize ulong: bytes
4294967296
minSize ulong: bytes
268435456
newRatio uint
2
startTime long: millis
230258101583
maxSize ulong: bytes
4294967296
minSize ulong: bytes
268435456
newRatio uint
2
startTime long: millis
286046075042
maxSize ulong: bytes
7725907968
minSize ulong: bytes
1363144
newRatio uint
2
startTime long: millis
218819075791

JVM: GC: Detailed

G1MMU

default profiling startTime 11 17 21 25 26

Category: Java Virtual Machine / GC / Detailed

Appearing in: G1GC

Missing in: ParallelGC, SerialGC, ShenandoahGC, ZGC

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/gc/shared/gcTraceSend.cpp:

#if INCLUDE_G1GC
void G1NewTracer::send_g1_young_gc_event() {
  EventG1GarbageCollection e(UNTIMED);
  if (e.should_commit()) {
    e.set_gcId(GCId::current());
    e.set_type(_g1_young_gc_info.type());
    e.set_starttime(_shared_gc_info.start_timestamp());
    e.set_endtime(_shared_gc_info.end_timestamp());
    e.commit();
  }
}

void G1MMUTracer::send_g1_mmu_event(double time_slice_ms, double gc_time_ms, double max_time_ms) {
  EventG1MMU e;
  if (e.should_commit()) {
    e.set_gcId(GCId::current());
    e.set_timeSlice(time_slice_ms);
    e.set_gcTime(gc_time_ms);
    e.set_pauseTarget(max_time_ms);
    e.commit();
  }
}

void G1NewTracer::send_evacuation_info_event(EvacuationInfo* info) {
  EventEvacuationInformation e;

Configuration enabled
default true
profiling true

Field Type Description
gcId uint GC Identifier
timeSlice long: millis Time Slice Time slice used to calculate MMU
gcTime long: millis GC Time Time stopped because of GC during last time slice
pauseTarget long: millis Pause Target Max time allowed to be spent on GC during last time slice

Examples 1
gcId uint
894
gcTime long: millis
5
pauseTarget long: millis
200
startTime long: millis
243344262583
timeSlice long: millis
201

EvacuationInformation

default profiling startTime 11 17 21 25 26

Category: Java Virtual Machine / GC / Detailed

Appearing in: G1GC

Missing in: ParallelGC, SerialGC, ShenandoahGC, ZGC

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/gc/shared/gcTraceSend.cpp:

void G1MMUTracer::send_g1_mmu_event(double time_slice_ms, double gc_time_ms, double max_time_ms) {
  EventG1MMU e;
  if (e.should_commit()) {
    e.set_gcId(GCId::current());
    e.set_timeSlice(time_slice_ms);
    e.set_gcTime(gc_time_ms);
    e.set_pauseTarget(max_time_ms);
    e.commit();
  }
}

void G1NewTracer::send_evacuation_info_event(EvacuationInfo* info) {
  EventEvacuationInformation e;
  if (e.should_commit()) {
    e.set_gcId(GCId::current());
    e.set_cSetRegions(info->collectionset_regions());
    e.set_cSetUsedBefore(info->collectionset_used_before());
    e.set_cSetUsedAfter(info->collectionset_used_after());
    e.set_allocationRegions(info->allocation_regions());
    e.set_allocationRegionsUsedBefore(info->alloc_regions_used_before());
    e.set_allocationRegionsUsedAfter(info->alloc_regions_used_before() + info->bytes_copied());
    e.set_bytesCopied(info->bytes_copied());
    e.set_regionsFreed(info->regions_freed());
    e.commit();

Configuration enabled
default true
profiling true

Field Type Description
gcId uint GC Identifier
cSetRegions uint Collection Set Regions
cSetUsedBefore ulong: bytes Collection Set Before Memory usage before GC in the collection set regions
cSetUsedAfter ulong: bytes Collection Set After Memory usage after GC in the collection set regions
allocationRegions uint Allocation Regions Regions chosen as allocation regions during evacuation (includes survivors and old space regions)
allocationRegionsUsedBefore ulong: bytes Allocation Regions Before Memory usage before GC in allocation regions
allocationRegionsUsedAfter ulong: bytes Allocation Regions After Memory usage after GC in allocation regions
bytesCopied ulong: bytes Bytes Copied
regionsFreed uint Regions Freed

Examples 1
allocationRegions uint
4
allocationRegionsUsedAfter ulong: bytes
18784232
allocationRegionsUsedBefore ulong: bytes
0
bytesCopied ulong: bytes
18784232
cSetRegions uint
69
cSetUsedAfter ulong: bytes
0
cSetUsedBefore ulong: bytes
569918624
gcId uint
821
regionsFreed uint
69
startTime long: millis
225253125625

ObjectCountAfterGC

startTime 11 17 21 25 26

Category: Java Virtual Machine / GC / Detailed

Appearing in: G1GC, ParallelGC, SerialGC

Missing in: ShenandoahGC, ZGC

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/gc/shared/objectCountEventSender.cpp:

#if INCLUDE_SERVICES

bool ObjectCountEventSender::should_send_event() {
#if INCLUDE_JFR
  return _should_send_requestable_event || EventObjectCountAfterGC::is_enabled();
#else
  return false;
#endif // INCLUDE_JFR
}

bool ObjectCountEventSender::_should_send_requestable_event = false;

void ObjectCountEventSender::enable_requestable_event() {
  _should_send_requestable_event = true;
}

src/hotspot/share/gc/shared/objectCountEventSender.cpp:

template <typename T>
void ObjectCountEventSender::send_event_if_enabled(Klass* klass, jlong count, julong size, const Ticks& timestamp) {
  T event(UNTIMED);
  if (event.should_commit()) {
    event.set_gcId(GCId::current());
    event.set_objectClass(klass);
    event.set_count(count);
    event.set_totalSize(size);
    event.set_endtime(timestamp);
    event.commit();
  }
}

void ObjectCountEventSender::send(const KlassInfoEntry* entry, const Ticks& timestamp) {
  Klass* klass = entry->klass();
  jlong count = entry->count();
  julong total_size = entry->words() * BytesPerWord;

  send_event_if_enabled<EventObjectCount>(klass, count, total_size, timestamp);
  send_event_if_enabled<EventObjectCountAfterGC>(klass, count, total_size, timestamp);
}

#endif // INCLUDE_SERVICES

Configuration enabled
default false
profiling false

Field Type Description
gcId uint GC Identifier
objectClass Class Object Class Consider contributing a description to jfreventcollector.
count long Count
totalSize ulong: bytes Total Size

Examples 3
count long
402499
gcId uint
788
objectClass Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
17
name string
java/lang/String
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/lang
startTime long: millis
202840215625
totalSize ulong: bytes
9659976
count long
62056
gcId uint
712
objectClass Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
17
name string
java/lang/reflect/Method
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/lang/reflect
startTime long: millis
254688807792
totalSize ulong: bytes
5460928
count long
100896
gcId uint
308
objectClass Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
17
name string
java/lang/Class
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/lang
startTime long: millis
235071137583
totalSize ulong: bytes
11738256

G1EvacuationYoungStatistics

default profiling startTime 11 17 21 25 26

Category: Java Virtual Machine / GC / Detailed

Appearing in: G1GC

Missing in: ParallelGC, SerialGC, ShenandoahGC, ZGC

Memory related evacuation statistics during GC for the young generation

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/gc/shared/gcTraceSend.cpp:

  s.set_allocated(summary.allocated() * HeapWordSize);
  s.set_wasted(summary.wasted() * HeapWordSize);
  s.set_used(summary.used() * HeapWordSize);
  s.set_undoWaste(summary.undo_wasted() * HeapWordSize);
  s.set_regionEndWaste(summary.region_end_waste() * HeapWordSize);
  s.set_regionsRefilled(summary.regions_filled());
  s.set_directAllocated(summary.direct_allocated() * HeapWordSize);
  s.set_failureUsed(summary.failure_used() * HeapWordSize);
  s.set_failureWaste(summary.failure_waste() * HeapWordSize);
  return s;
}

void G1NewTracer::send_young_evacuation_statistics(const G1EvacSummary& summary) const {
  EventG1EvacuationYoungStatistics surv_evt;
  if (surv_evt.should_commit()) {
    surv_evt.set_statistics(create_g1_evacstats(GCId::current(), summary));
    surv_evt.commit();
  }
}

void G1NewTracer::send_old_evacuation_statistics(const G1EvacSummary& summary) const {
  EventG1EvacuationOldStatistics old_evt;
  if (old_evt.should_commit()) {
    old_evt.set_statistics(create_g1_evacstats(GCId::current(), summary));
    old_evt.commit();

Configuration enabled
default true
profiling true

Field Type Description
statistics G1EvacuationStatistics struct Evacuation Statistics

Examples 1
startTime long: millis
241335955916
statistics G1EvacuationStatistics
allocated ulong: bytes
6371328
directAllocated ulong: bytes
613344
failureUsed ulong: bytes
0
failureWaste ulong: bytes
0
gcId uint
878
regionEndWaste ulong: bytes
0
regionsRefilled uint: bytes
1
undoWaste ulong: bytes
0
used ulong: bytes
5977712
wasted ulong: bytes
11632

G1EvacuationOldStatistics

default profiling startTime 11 17 21 25 26

Category: Java Virtual Machine / GC / Detailed

Appearing in: G1GC

Missing in: ParallelGC, SerialGC, ShenandoahGC, ZGC

Memory related evacuation statistics during GC for the old generation

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/gc/shared/gcTraceSend.cpp:

  s.set_failureWaste(summary.failure_waste() * HeapWordSize);
  return s;
}

void G1NewTracer::send_young_evacuation_statistics(const G1EvacSummary& summary) const {
  EventG1EvacuationYoungStatistics surv_evt;
  if (surv_evt.should_commit()) {
    surv_evt.set_statistics(create_g1_evacstats(GCId::current(), summary));
    surv_evt.commit();
  }
}

void G1NewTracer::send_old_evacuation_statistics(const G1EvacSummary& summary) const {
  EventG1EvacuationOldStatistics old_evt;
  if (old_evt.should_commit()) {
    old_evt.set_statistics(create_g1_evacstats(GCId::current(), summary));
    old_evt.commit();
  }
}

void G1NewTracer::send_basic_ihop_statistics(size_t threshold,
                                             size_t target_occupancy,
                                             size_t current_occupancy,
                                             size_t last_allocation_size,
                                             double last_allocation_duration,

Configuration enabled
default true
profiling true

Field Type Description
statistics G1EvacuationStatistics struct Evacuation Statistics

Examples 1
startTime long: millis
233681298333
statistics G1EvacuationStatistics
allocated ulong: bytes
0
directAllocated ulong: bytes
0
failureUsed ulong: bytes
0
failureWaste ulong: bytes
0
gcId uint
842
regionEndWaste ulong: bytes
0
regionsRefilled uint: bytes
0
undoWaste ulong: bytes
0
used ulong: bytes
0
wasted ulong: bytes
0

G1BasicIHOP

default profiling startTime 11 17 21 25 26

Category: Java Virtual Machine / GC / Detailed

Appearing in: G1GC

Missing in: ParallelGC, SerialGC, ShenandoahGC, ZGC

Basic statistics related to current IHOP calculation

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/gc/shared/gcTraceSend.cpp:

  EventG1EvacuationOldStatistics old_evt;
  if (old_evt.should_commit()) {
    old_evt.set_statistics(create_g1_evacstats(GCId::current(), summary));
    old_evt.commit();
  }
}

void G1NewTracer::send_basic_ihop_statistics(size_t threshold,
                                             size_t target_occupancy,
                                             size_t current_occupancy,
                                             size_t last_allocation_size,
                                             double last_allocation_duration,
                                             double last_marking_length) {
  EventG1BasicIHOP evt;
  if (evt.should_commit()) {
    evt.set_gcId(GCId::current());
    evt.set_threshold(threshold);
    evt.set_targetOccupancy(target_occupancy);
    evt.set_thresholdPercentage(target_occupancy > 0 ? ((double)threshold / target_occupancy) : 0.0);
    evt.set_currentOccupancy(current_occupancy);
    evt.set_recentMutatorAllocationSize(last_allocation_size);
    evt.set_recentMutatorDuration(last_allocation_duration * MILLIUNITS);
    evt.set_recentAllocationRate(last_allocation_duration != 0.0 ? last_allocation_size / last_allocation_duration : 0.0);
    evt.set_lastMarkingDuration(last_marking_length * MILLIUNITS);
    evt.commit();

Configuration enabled
default true
profiling true

Field Type Description
gcId uint GC Identifier
threshold ulong: bytes Current IHOP Threshold Current IHOP threshold
thresholdPercentage float: percentage Current IHOP Threshold Current IHOP threshold in percent of old generation
targetOccupancy ulong: bytes Target Occupancy Target old generation occupancy to reach at the start of mixed GC
currentOccupancy ulong: bytes Current Occupancy Current old generation occupancy
recentMutatorAllocationSize ulong: bytes Recent Mutator Allocation Size Mutator allocation during mutator operation in the most recent interval
recentMutatorDuration long: millis Recent Mutator Duration Time the mutator ran in the most recent interval
recentAllocationRate double: bytes-per-second Recent Allocation Rate Allocation rate of the mutator in the most recent interval in bytes/second
lastMarkingDuration long: millis Last Marking Duration Last time from the end of the last initial mark to the first mixed GC

Examples 1
currentOccupancy ulong: bytes
245167240
gcId uint
822
lastMarkingDuration long: millis
264
recentAllocationRate double: bytes-per-second
0.0
recentMutatorAllocationSize ulong: bytes
0
recentMutatorDuration long: millis
123
startTime long: millis
225378419125
targetOccupancy ulong: bytes
956301312
threshold ulong: bytes
0
thresholdPercentage float: percentage
0.0

G1AdaptiveIHOP

default profiling startTime 11 17 21 25 26

Category: Java Virtual Machine / GC / Detailed

Appearing in: G1GC

Missing in: ParallelGC, SerialGC, ShenandoahGC, ZGC

Statistics related to current adaptive IHOP calculation

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/gc/shared/gcTraceSend.cpp:

    evt.set_recentAllocationRate(last_allocation_duration != 0.0 ? last_allocation_size / last_allocation_duration : 0.0);
    evt.set_lastMarkingDuration(last_marking_length * MILLIUNITS);
    evt.commit();
  }
}

void G1NewTracer::send_adaptive_ihop_statistics(size_t threshold,
                                                size_t internal_target_occupancy,
                                                size_t current_occupancy,
                                                size_t additional_buffer_size,
                                                double predicted_allocation_rate,
                                                double predicted_marking_length,
                                                bool prediction_active) {
  EventG1AdaptiveIHOP evt;
  if (evt.should_commit()) {
    evt.set_gcId(GCId::current());
    evt.set_threshold(threshold);
    evt.set_thresholdPercentage(internal_target_occupancy > 0 ? ((double)threshold / internal_target_occupancy) : 0.0);
    evt.set_ihopTargetOccupancy(internal_target_occupancy);
    evt.set_currentOccupancy(current_occupancy);
    evt.set_additionalBufferSize(additional_buffer_size);
    evt.set_predictedAllocationRate(predicted_allocation_rate);
    evt.set_predictedMarkingDuration(predicted_marking_length * MILLIUNITS);
    evt.set_predictionActive(prediction_active);
    evt.commit();

Configuration enabled
default true
profiling true

Field Type Description
gcId uint GC Identifier
threshold ulong: bytes Threshold Current IHOP Threshold
thresholdPercentage float: percentage Threshold Current IHOP threshold in percent of the internal target occupancy
ihopTargetOccupancy ulong: bytes IHOP Target Occupancy Internal target old generation occupancy to reach at the start of mixed GC
currentOccupancy ulong: bytes Current Occupancy Current old generation occupancy
additionalBufferSize ulong: bytes Additional Buffer Additional buffer size
predictedAllocationRate double: bytes-per-second Predicted Allocation Rate Current predicted allocation rate for the mutator in bytes/second
predictedMarkingDuration long: millis Predicted Marking Duration Current predicted time from the end of the last initial mark to the first mixed GC
predictionActive boolean Prediction Active Indicates whether the adaptive IHOP prediction is active

Examples 1
additionalBufferSize ulong: bytes
578813952
currentOccupancy ulong: bytes
230963792
gcId uint
812
ihopTargetOccupancy ulong: bytes
916455424
predictedAllocationRate double: bytes-per-second
2.945689613301255E9
predictedMarkingDuration long: millis
429
predictionActive boolean
true
startTime long: millis
224430067791
threshold ulong: bytes
0
thresholdPercentage float: percentage
0.0

PromoteObjectInNewPLAB

profiling startTime eventThread 11 17 21 25 26

Category: Java Virtual Machine / GC / Detailed

Appearing in: G1GC, ParallelGC

Missing in: SerialGC, ShenandoahGC, ZGC

Object survived scavenge and was copied to a new Promotion Local Allocation Buffer (PLAB). Supported GCs are Parallel Scavange, G1 and CMS with Parallel New. Due to promotion being done in parallel an object might be reported multiple times as the GC threads race to copy all objects.

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/gc/shared/gcTraceSend.cpp:

void YoungGCTracer::send_young_gc_event() const {
  EventYoungGarbageCollection e(UNTIMED);
  if (e.should_commit()) {
    e.set_gcId(GCId::current());
    e.set_tenuringThreshold(_tenuring_threshold);
    e.set_starttime(_shared_gc_info.start_timestamp());
    e.set_endtime(_shared_gc_info.end_timestamp());
    e.commit();
  }
}

bool YoungGCTracer::should_send_promotion_in_new_plab_event() const {
  return EventPromoteObjectInNewPLAB::is_enabled();
}

bool YoungGCTracer::should_send_promotion_outside_plab_event() const {
  return EventPromoteObjectOutsidePLAB::is_enabled();
}

void YoungGCTracer::send_promotion_in_new_plab_event(Klass* klass, size_t obj_size,
                                                     uint age, bool tenured,
                                                     size_t plab_size) const {

  EventPromoteObjectInNewPLAB event;
  if (event.should_commit()) {
    event.set_gcId(GCId::current());
    event.set_objectClass(klass);
    event.set_objectSize(obj_size);
    event.set_tenured(tenured);
    event.set_tenuringAge(age);
    event.set_plabSize(plab_size);
    event.commit();
  }
}

Configuration enabled
default false
profiling true

Field Type Description
gcId uint GC Identifier Identifier signifying GC during which the object was promoted
objectClass Class Object Class Class of promoted object
objectSize ulong: bytes Object Size Size of promoted object
tenuringAge uint Object Tenuring Age Tenuring age of a surviving object before being copied. The tenuring age of an object is a value between 0-15 and is incremented each scavange the object survives. Newly allocated objects have tenuring age 0.
tenured boolean Tenured True if object was promoted to Old space, otherwise the object was aged and copied to a Survivor space
plabSize ulong: bytes PLAB Size Size of the allocated PLAB to which the object was copied

Examples 2
gcId uint
297
objectClass Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/net
hidden boolean
false
modifiers int
1041
name string
[Lorg/apache/spark/storage/FileSegment;
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/net
location string
null
name string
null
version string
null
name string
org/apache/spark/storage
objectSize ulong: bytes
56
plabSize ulong: bytes
32752
startTime long: millis
230210640833
tenured boolean
false
tenuringAge uint
0
gcId uint
778
objectClass Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1041
name string
[F
package Package
null
objectSize ulong: bytes
56
plabSize ulong: bytes
29432
startTime long: millis
199113512291
tenured boolean
false
tenuringAge uint
0

PromoteObjectOutsidePLAB

profiling startTime eventThread 11 17 21 25 26

Category: Java Virtual Machine / GC / Detailed

Appearing in: G1GC, ParallelGC

Missing in: SerialGC, ShenandoahGC, ZGC

Object survived scavenge and was copied directly to the heap. Supported GCs are Parallel Scavange, G1 and CMS with Parallel New. Due to promotion being done in parallel an object might be reported multiple times as the GC threads race to copy all objects.

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/gc/shared/gcTraceSend.cpp:

    e.set_gcId(GCId::current());
    e.set_tenuringThreshold(_tenuring_threshold);
    e.set_starttime(_shared_gc_info.start_timestamp());
    e.set_endtime(_shared_gc_info.end_timestamp());
    e.commit();
  }
}

bool YoungGCTracer::should_send_promotion_in_new_plab_event() const {
  return EventPromoteObjectInNewPLAB::is_enabled();
}

bool YoungGCTracer::should_send_promotion_outside_plab_event() const {
  return EventPromoteObjectOutsidePLAB::is_enabled();
}

void YoungGCTracer::send_promotion_in_new_plab_event(Klass* klass, size_t obj_size,
                                                     uint age, bool tenured,
                                                     size_t plab_size) const {

  EventPromoteObjectInNewPLAB event;
  if (event.should_commit()) {
    event.set_gcId(GCId::current());
    event.set_objectClass(klass);
    event.set_objectSize(obj_size);
    event.set_tenured(tenured);
    event.set_tenuringAge(age);
    event.set_plabSize(plab_size);
    event.commit();
  }
}

void YoungGCTracer::send_promotion_outside_plab_event(Klass* klass, size_t obj_size,
                                                      uint age, bool tenured) const {

  EventPromoteObjectOutsidePLAB event;
  if (event.should_commit()) {
    event.set_gcId(GCId::current());
    event.set_objectClass(klass);
    event.set_objectSize(obj_size);
    event.set_tenured(tenured);
    event.set_tenuringAge(age);
    event.commit();
  }
}

void OldGCTracer::send_old_gc_event() const {

Configuration enabled
default false
profiling true

Field Type Description
gcId uint GC Identifier Identifier signifying GC during which the object was promoted
objectClass Class Object Class Class of promoted object
objectSize ulong: bytes Object Size Size of promoted object
tenuringAge uint Object Tenuring Age Tenuring age of a surviving object before being copied. The tenuring age of an object is a value between 0-15 and is incremented each scavange the object survives. Newly allocated objects have tenuring age 0.
tenured boolean Tenured True if object was promoted to Old space, otherwise the object was aged and copied to a Survivor space

Examples 2
gcId uint
297
objectClass Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1041
name string
[B
package Package
null
objectSize ulong: bytes
32784
startTime long: millis
230210647625
tenured boolean
false
tenuringAge uint
0
gcId uint
790
objectClass Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1041
name string
[[F
package Package
null
objectSize ulong: bytes
8016
startTime long: millis
205967392458
tenured boolean
false
tenuringAge uint
0

PromotionFailed

default profiling startTime 11 17 21 25 26

Category: Java Virtual Machine / GC / Detailed

Promotion of an object failed

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/gc/shared/gcTraceSend.cpp:

static JfrStructCopyFailed to_struct(const CopyFailedInfo& cf_info) {
  JfrStructCopyFailed failed_info;
  failed_info.set_objectCount(cf_info.failed_count());
  failed_info.set_firstSize(cf_info.first_size());
  failed_info.set_smallestSize(cf_info.smallest_size());
  failed_info.set_totalSize(cf_info.total_size());
  return failed_info;
}

void YoungGCTracer::send_promotion_failed_event(const PromotionFailedInfo& pf_info) const {
  EventPromotionFailed e;
  if (e.should_commit()) {
    e.set_gcId(GCId::current());
    e.set_promotionFailed(to_struct(pf_info));
    e.set_thread(pf_info.thread_trace_id());
    e.commit();
  }
}

// Common to CMS and G1
void OldGCTracer::send_concurrent_mode_failure_event() {
  EventConcurrentModeFailure e;

Configuration enabled
default true
profiling true

Field Type Description
gcId uint GC Identifier
promotionFailed CopyFailed struct Promotion Failed Data
thread Thread Running thread

EvacuationFailed

default profiling startTime 11 17 21 25 26

Category: Java Virtual Machine / GC / Detailed

Evacuation of an object failed

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/gc/shared/gcTraceSend.cpp:

    e.set_cSetRegions(info->collectionset_regions());
    e.set_cSetUsedBefore(info->collectionset_used_before());
    e.set_cSetUsedAfter(info->collectionset_used_after());
    e.set_allocationRegions(info->allocation_regions());
    e.set_allocationRegionsUsedBefore(info->alloc_regions_used_before());
    e.set_allocationRegionsUsedAfter(info->alloc_regions_used_before() + info->bytes_copied());
    e.set_bytesCopied(info->bytes_copied());
    e.set_regionsFreed(info->regions_freed());
    e.commit();
  }
}

void G1NewTracer::send_evacuation_failed_event(const EvacuationFailedInfo& ef_info) const {
  EventEvacuationFailed e;
  if (e.should_commit()) {
    e.set_gcId(GCId::current());
    e.set_evacuationFailed(to_struct(ef_info));
    e.commit();
  }
}

static JfrStructG1EvacuationStatistics
create_g1_evacstats(unsigned gcid, const G1EvacSummary& summary) {
  JfrStructG1EvacuationStatistics s;
  s.set_gcId(gcid);

Configuration enabled
default true
profiling true

Field Type Description
gcId uint GC Identifier
evacuationFailed CopyFailed struct Evacuation Failed Data

ConcurrentModeFailure

default profiling startTime 11 17 21 25 26

Category: Java Virtual Machine / GC / Detailed

Appearing in: G1GC

Missing in: ParallelGC, SerialGC, ShenandoahGC, ZGC

Concurrent Mode failed

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/gc/shared/gcTraceSend.cpp:

void YoungGCTracer::send_promotion_failed_event(const PromotionFailedInfo& pf_info) const {
  EventPromotionFailed e;
  if (e.should_commit()) {
    e.set_gcId(GCId::current());
    e.set_promotionFailed(to_struct(pf_info));
    e.set_thread(pf_info.thread_trace_id());
    e.commit();
  }
}

// Common to CMS and G1
void OldGCTracer::send_concurrent_mode_failure_event() {
  EventConcurrentModeFailure e;
  if (e.should_commit()) {
    e.set_gcId(GCId::current());
    e.commit();
  }
}

#if INCLUDE_G1GC
void G1NewTracer::send_g1_young_gc_event() {
  EventG1GarbageCollection e(UNTIMED);
  if (e.should_commit()) {
    e.set_gcId(GCId::current());

Configuration enabled
default true
profiling true

Field Type Description
gcId uint GC Identifier

Examples 1
gcId uint
785
startTime long: millis
201508787541

AllocationRequiringGC

startTime eventThread stackTrace 11 17 21 25 26

Category: Java Virtual Machine / GC / Detailed

Appearing in: G1GC, ParallelGC, SerialGC

Missing in: ShenandoahGC, ZGC

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/gc/shared/allocTracer.cpp:

    event.set_allocationSize(alloc_size);
    event.commit();
  }
}

void AllocTracer::send_allocation_in_new_tlab(Klass* klass, HeapWord* obj, size_t tlab_size, size_t alloc_size, Thread* thread) {
  JFR_ONLY(JfrAllocationTracer tracer(obj, alloc_size, thread);)
  EventObjectAllocationInNewTLAB event;
  if (event.should_commit()) {
    event.set_objectClass(klass);
    event.set_allocationSize(alloc_size);
    event.set_tlabSize(tlab_size);
    event.commit();
  }
}

void AllocTracer::send_allocation_requiring_gc_event(size_t size, uint gcId) {
  EventAllocationRequiringGC event;
  if (event.should_commit()) {
    event.set_gcId(gcId);
    event.set_size(size);
    event.commit();
  }
}

Configuration enabled stackTrace
default false true
profiling false true

Field Type Description
gcId uint Pending GC Identifier
size ulong: bytes Allocation Size

Examples 3
gcId uint
322
size ulong: bytes
24
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
6
lineNumber int
400
method Method
descriptor string
([BJ)Ljava/lang/String;
hidden boolean
false
modifiers int
8
name string
newString
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
16
name string
java/lang/StringConcatHelper
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/lang
type FrameType
Inlined
truncated boolean
true
startTime long: millis
246390838667
gcId uint
830
size ulong: bytes
16
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
0
lineNumber int
120
method Method
descriptor string
(Lcom/twitter/util/Try;)Lcom/twitter/util/Future;
hidden boolean
false
modifiers int
1
name string
const
type Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/net
hidden boolean
false
modifiers int
17
name string
com/twitter/util/Future$
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/net
location string
null
name string
null
version string
null
name string
com/twitter/util
type FrameType
Inlined
truncated boolean
true
startTime long: millis
292966083708
gcId uint
921
size ulong: bytes
143848
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
5
lineNumber int
1255
method Method
descriptor string
(Ljava/lang/String;Lscala/Function1;)Ljava/lang/String;
hidden boolean
false
modifiers int
17
name string
filter$extension
type Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/net
hidden boolean
false
modifiers int
17
name string
scala/collection/StringOps$
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/net
location string
null
name string
null
version string
null
name string
scala/collection
type FrameType
Inlined
truncated boolean
false
startTime long: millis
253442732000

TenuringDistribution

default profiling startTime 11 17 21 25 26

Category: Java Virtual Machine / GC / Detailed

Appearing in: G1GC, SerialGC

Missing in: ParallelGC, ShenandoahGC, ZGC

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/gc/shared/ageTableTracer.cpp:

void AgeTableTracer::send_tenuring_distribution_event(uint age, size_t size) {
  EventTenuringDistribution e;
  if (e.should_commit()) {
    e.set_gcId(GCId::current());
    e.set_age(age);
    e.set_size(size);
    e.commit();
  }
}

bool AgeTableTracer::is_tenuring_distribution_event_enabled() {
  return EventTenuringDistribution::is_enabled();
}

Configuration enabled
default true
profiling true

Field Type Description
gcId uint GC Identifier
age uint Age
size ulong: bytes Size

Examples 2
age uint
3
gcId uint
725
size ulong: bytes
1248592
startTime long: millis
265242638667
age uint
12
gcId uint
780
size ulong: bytes
0
startTime long: millis
199166846708

G1HeapRegionTypeChange

startTime 11 17 21 25 26

Category: Java Virtual Machine / GC / Detailed

Appearing in: G1GC

Missing in: ParallelGC, SerialGC, ShenandoahGC, ZGC

Information about a G1 heap region type change

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/gc/g1/heapRegionTracer.cpp:

void HeapRegionTracer::send_region_type_change(uint index,
                                               G1HeapRegionTraceType::Type from,
                                               G1HeapRegionTraceType::Type to,
                                               uintptr_t start,
                                               size_t used) {
  EventG1HeapRegionTypeChange e;
  if (e.should_commit()) {
    e.set_index(index);
    e.set_from(from);
    e.set_to(to);
    e.set_start(start);
    e.set_used(used);
    e.commit();
  }
}

Configuration enabled
default false
profiling false

Field Type Description
index uint Index
from G1HeapRegionType From Consider contributing a description to jfreventcollector.
to G1HeapRegionType To Consider contributing a description to jfreventcollector.
start ulong: address Start
used ulong: bytes Used

Examples 1
from G1HeapRegionType
Free
index uint
163
start ulong: address
22842179584
startTime long: millis
199114847541
to G1HeapRegionType
Free
used ulong: bytes
0

ObjectCount

startTime every chunk 11 17 21 25 26

Category: Java Virtual Machine / GC / Detailed

Appearing in: G1GC, ParallelGC, SerialGC

Missing in: ShenandoahGC, ZGC

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/gc/shared/objectCountEventSender.cpp:

template <typename T>
void ObjectCountEventSender::send_event_if_enabled(Klass* klass, jlong count, julong size, const Ticks& timestamp) {
  T event(UNTIMED);
  if (event.should_commit()) {
    event.set_gcId(GCId::current());
    event.set_objectClass(klass);
    event.set_count(count);
    event.set_totalSize(size);
    event.set_endtime(timestamp);
    event.commit();
  }
}

void ObjectCountEventSender::send(const KlassInfoEntry* entry, const Ticks& timestamp) {
  Klass* klass = entry->klass();
  jlong count = entry->count();
  julong total_size = entry->words() * BytesPerWord;

  send_event_if_enabled<EventObjectCount>(klass, count, total_size, timestamp);
  send_event_if_enabled<EventObjectCountAfterGC>(klass, count, total_size, timestamp);
}

#endif // INCLUDE_SERVICES

Configuration enabled period
default false everyChunk
profiling false everyChunk

Field Type Description
gcId uint GC Identifier
objectClass Class Object Class Consider contributing a description to jfreventcollector.
count long Count
totalSize ulong: bytes Total Size

Examples 3
count long
4152
gcId uint
300
objectClass Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1041
name string
[C
package Package
null
startTime long: millis
231250573083
totalSize ulong: bytes
4160512
count long
81829
gcId uint
780
objectClass Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
8
name string
java/util/HashMap$Node
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/util
startTime long: millis
199152438958
totalSize ulong: bytes
2618528
count long
63282
gcId uint
710
objectClass Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
16
name string
java/lang/invoke/MemberName
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/lang/invoke
startTime long: millis
248955255750
totalSize ulong: bytes
3037536

G1HeapRegionInformation

startTime duration every chunk 11 17 21 25 26

Category: Java Virtual Machine / GC / Detailed

Appearing in: G1GC

Missing in: ParallelGC, SerialGC, ShenandoahGC, ZGC

Information about a specific heap region in the G1 GC

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/gc/g1/g1HeapRegionEventSender.cpp:

class DumpEventInfoClosure : public HeapRegionClosure {
public:
  bool do_heap_region(HeapRegion* r) {
    EventG1HeapRegionInformation evt;
    evt.set_index(r->hrm_index());
    evt.set_type(r->get_trace_type());
    evt.set_start((uintptr_t)r->bottom());
    evt.set_used(r->used());
    evt.commit();
    return false;
  }
};


void G1HeapRegionEventSender::send_events() {
  DumpEventInfoClosure c;

  G1CollectedHeap::heap()->heap_region_iterate(&c);

Configuration enabled period
default false everyChunk
profiling false everyChunk

Field Type Description
index uint Index
type G1HeapRegionType Type Consider contributing a description to jfreventcollector.
start ulong: address Start
used ulong: bytes Used

Examples 1
index uint
57
start ulong: address
21952987136
startTime long: millis
199167072708
type G1HeapRegionType
Free
used ulong: bytes
0

ZPageAllocation

experimental default profiling startTime duration eventThread 11 17 21 25 26

Category: Java Virtual Machine / GC / Detailed

Appearing in: ZGC

Missing in: G1GC, ParallelGC, SerialGC, ShenandoahGC

Allocation of a ZPage

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/gc/z/zTracer.cpp:

  EventZThreadPhase e(UNTIMED);
  if (e.should_commit()) {
    e.set_gcId(GCId::current_or_undefined());
    e.set_name(name);
    e.set_starttime(start);
    e.set_endtime(end);
    e.commit();
  }
}

void ZTracer::send_page_alloc(size_t size, size_t used, size_t free, size_t cache, bool nonblocking, bool noreserve) {
  NoSafepointVerifier nsv(true, !SafepointSynchronize::is_at_safepoint());

  EventZPageAllocation e;
  if (e.should_commit()) {
    e.set_pageSize(size);
    e.set_usedAfter(used);
    e.set_freeAfter(free);
    e.set_inCacheAfter(cache);
    e.set_nonBlocking(nonblocking);
    e.set_noReserve(noreserve);
    e.commit();
  }
}

Configuration enabled threshold
default true 10 ms
profiling true 10 ms

Field Type Description
pageSize ulong: bytes 11 until JDK 15 Page Size
usedAfter ulong: bytes 11 until JDK 15 Used After
freeAfter ulong: bytes 11 until JDK 15 Free After
inCacheAfter ulong: bytes 11 until JDK 15 In Cache After
nonBlocking boolean Non-blocking
noReserve boolean 11 until JDK 16 No Reserve

Examples 1
nonBlocking boolean
false
startTime long: millis
272471223834

ZThreadPhase

experimental default profiling startTime duration eventThread 11 17 21 25 26

Category: Java Virtual Machine / GC / Detailed

Appearing in: ZGC

Missing in: G1GC, ParallelGC, SerialGC, ShenandoahGC

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/gc/z/zTracer.cpp:

  NoSafepointVerifier nsv(true, !SafepointSynchronize::is_at_safepoint());

  EventZStatisticsSampler e;
  if (e.should_commit()) {
    e.set_id(sampler_id);
    e.set_value(value);
    e.commit();
  }
}

void ZTracer::send_thread_phase(const char* name, const Ticks& start, const Ticks& end) {
  NoSafepointVerifier nsv(true, !SafepointSynchronize::is_at_safepoint());

  EventZThreadPhase e(UNTIMED);
  if (e.should_commit()) {
    e.set_gcId(GCId::current_or_undefined());
    e.set_name(name);
    e.set_starttime(start);
    e.set_endtime(end);
    e.commit();
  }
}

void ZTracer::send_page_alloc(size_t size, size_t used, size_t free, size_t cache, bool nonblocking, bool noreserve) {
  NoSafepointVerifier nsv(true, !SafepointSynchronize::is_at_safepoint());

Configuration enabled threshold
default true 0 ms
profiling true 0 ms

Field Type Description
gcId uint GC Identifier
name string Name

Examples 1
gcId uint
191
name string
Pause Mark Try Complete
startTime long: millis
231967080584

ZStatisticsCounter

experimental default profiling startTime duration eventThread 11 17 21 25 26

Category: Java Virtual Machine / GC / Detailed

Appearing in: ZGC

Missing in: G1GC, ParallelGC, SerialGC, ShenandoahGC

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/gc/z/zTracer.cpp:

ZTracer::ZTracer() :
    GCTracer(Z) {}

void ZTracer::initialize() {
  assert(_tracer == NULL, "Already initialized");
  _tracer = new (ResourceObj::C_HEAP, mtGC) ZTracer();
  JFR_ONLY(register_jfr_type_serializers());
}

void ZTracer::send_stat_counter(uint32_t counter_id, uint64_t increment, uint64_t value) {
  NoSafepointVerifier nsv(true, !SafepointSynchronize::is_at_safepoint());

  EventZStatisticsCounter e;
  if (e.should_commit()) {
    e.set_id(counter_id);
    e.set_increment(increment);
    e.set_value(value);
    e.commit();
  }
}

void ZTracer::send_stat_sampler(uint32_t sampler_id, uint64_t value) {
  NoSafepointVerifier nsv(true, !SafepointSynchronize::is_at_safepoint());

Configuration enabled threshold
default true 10 ms
profiling true 10 ms

Field Type Description
id ZStatisticsCounterType Id Consider contributing a description to jfreventcollector.
increment ulong Increment
value ulong Value

Examples 1
id ZStatisticsCounterType
Allocation Rate
increment ulong
2097152
startTime long: millis
230746623417
value ulong
16777216

ZStatisticsSampler

experimental default profiling startTime duration eventThread 11 17 21 25 26

Category: Java Virtual Machine / GC / Detailed

Appearing in: ZGC

Missing in: G1GC, ParallelGC, SerialGC, ShenandoahGC

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/gc/z/zTracer.cpp:

  EventZStatisticsCounter e;
  if (e.should_commit()) {
    e.set_id(counter_id);
    e.set_increment(increment);
    e.set_value(value);
    e.commit();
  }
}

void ZTracer::send_stat_sampler(uint32_t sampler_id, uint64_t value) {
  NoSafepointVerifier nsv(true, !SafepointSynchronize::is_at_safepoint());

  EventZStatisticsSampler e;
  if (e.should_commit()) {
    e.set_id(sampler_id);
    e.set_value(value);
    e.commit();
  }
}

void ZTracer::send_thread_phase(const char* name, const Ticks& start, const Ticks& end) {
  NoSafepointVerifier nsv(true, !SafepointSynchronize::is_at_safepoint());

  EventZThreadPhase e(UNTIMED);

Configuration enabled threshold
default true 10 ms
profiling true 10 ms

Field Type Description
id ZStatisticsSamplerType Id Consider contributing a description to jfreventcollector.
value ulong Value

Examples 1
id ZStatisticsSamplerType
Undo Page Allocation
startTime long: millis
230036702542
value ulong
9

JVM: GC: Heap

GCHeapSummary

default profiling startTime 11 17 21 25 26

Category: Java Virtual Machine / GC / Heap

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/gc/shared/gcTraceSend.cpp:

  space.set_used(summary.used());
  space.set_size(summary.size());
  return space;
}

class GCHeapSummaryEventSender : public GCHeapSummaryVisitor {
  GCWhen::Type _when;
 public:
  GCHeapSummaryEventSender(GCWhen::Type when) : _when(when) {}

  void visit(const GCHeapSummary* heap_summary) const {
    const VirtualSpaceSummary& heap_space = heap_summary->heap();

    EventGCHeapSummary e;
    if (e.should_commit()) {
      e.set_gcId(GCId::current());
      e.set_when((u1)_when);
      e.set_heapSpace(to_struct(heap_space));
      e.set_heapUsed(heap_summary->used());
      e.commit();
    }
  }

  void visit(const G1HeapSummary* g1_heap_summary) const {
    visit((GCHeapSummary*)g1_heap_summary);

Configuration enabled
default true
profiling true

Field Type Description
gcId uint GC Identifier
when GCWhen When Consider contributing a description to jfreventcollector.
heapSpace VirtualSpace struct Heap Space Consider contributing a description to jfreventcollector.
heapUsed ulong: bytes Heap Used Bytes allocated by objects in the heap

Examples 3
gcId uint
791
heapSpace VirtualSpace
committedEnd ulong: address
24847056896
committedSize ulong: bytes
3372220416
reservedEnd ulong: address
34359738368
reservedSize ulong: bytes
12884901888
start ulong: address
21474836480
heapUsed ulong: bytes
314907320
startTime long: millis
205969261875
when GCWhen
After GC
gcId uint
344
heapSpace VirtualSpace
committedEnd ulong: address
26848264192
committedSize ulong: bytes
5373427712
reservedEnd ulong: address
34359738368
reservedSize ulong: bytes
12884901888
start ulong: address
21474836480
heapUsed ulong: bytes
373607368
startTime long: millis
258336442500
when GCWhen
After GC
gcId uint
733
heapSpace VirtualSpace
committedEnd ulong: address
22529425408
committedSize ulong: bytes
1054588928
reservedEnd ulong: address
34359738368
reservedSize ulong: bytes
12884901888
start ulong: address
21474836480
heapUsed ulong: bytes
249280896
startTime long: millis
265933903875
when GCWhen
After GC

MetaspaceSummary

default profiling startTime 11 17 21 25 26

Category: Java Virtual Machine / GC / Heap

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/gc/shared/gcTraceSend.cpp:

static JfrStructMetaspaceSizes to_struct(const MetaspaceSizes& sizes) {
  JfrStructMetaspaceSizes meta_sizes;

  meta_sizes.set_committed(sizes.committed());
  meta_sizes.set_used(sizes.used());
  meta_sizes.set_reserved(sizes.reserved());

  return meta_sizes;
}

void GCTracer::send_meta_space_summary_event(GCWhen::Type when, const MetaspaceSummary& meta_space_summary) const {
  EventMetaspaceSummary e;
  if (e.should_commit()) {
    e.set_gcId(GCId::current());
    e.set_when((u1) when);
    e.set_gcThreshold(meta_space_summary.capacity_until_GC());
    e.set_metaspace(to_struct(meta_space_summary.meta_space()));
    e.set_dataSpace(to_struct(meta_space_summary.data_space()));
    e.set_classSpace(to_struct(meta_space_summary.class_space()));
    e.commit();
  }
}

Configuration enabled
default true
profiling true

Field Type Description
gcId uint GC Identifier
when GCWhen When Consider contributing a description to jfreventcollector.
gcThreshold ulong: bytes GC Threshold
metaspace MetaspaceSizes struct Total Consider contributing a description to jfreventcollector.
dataSpace MetaspaceSizes struct Data Consider contributing a description to jfreventcollector.
classSpace MetaspaceSizes struct Class Consider contributing a description to jfreventcollector.

Examples 3
classSpace MetaspaceSizes
committed ulong: bytes
92667904
reserved ulong: bytes
1073741824
used ulong: bytes
90744624
dataSpace MetaspaceSizes
committed ulong: bytes
585826304
reserved ulong: bytes
603979776
used ulong: bytes
583868592
gcId uint
728
gcThreshold ulong: bytes
1130758144
metaspace MetaspaceSizes
committed ulong: bytes
678494208
reserved ulong: bytes
1677721600
used ulong: bytes
674613216
startTime long: millis
265449562500
when GCWhen
After GC
classSpace MetaspaceSizes
committed ulong: bytes
92798976
reserved ulong: bytes
1073741824
used ulong: bytes
90785936
dataSpace MetaspaceSizes
committed ulong: bytes
588054528
reserved ulong: bytes
603979776
used ulong: bytes
586124072
gcId uint
325
gcThreshold ulong: bytes
1134231552
metaspace MetaspaceSizes
committed ulong: bytes
680853504
reserved ulong: bytes
1677721600
used ulong: bytes
676910008
startTime long: millis
246877357792
when GCWhen
After GC
classSpace MetaspaceSizes
committed ulong: bytes
91160576
reserved ulong: bytes
1073741824
used ulong: bytes
89210912
dataSpace MetaspaceSizes
committed ulong: bytes
574095360
reserved ulong: bytes
603979776
used ulong: bytes
572158760
gcId uint
801
gcThreshold ulong: bytes
1108672512
metaspace MetaspaceSizes
committed ulong: bytes
665255936
reserved ulong: bytes
1677721600
used ulong: bytes
661369672
startTime long: millis
217936259833
when GCWhen
Before GC

PSHeapSummary

default profiling startTime 11 17 21 25 26

Category: Java Virtual Machine / GC / Heap

Appearing in: ParallelGC

Missing in: G1GC, SerialGC, ShenandoahGC, ZGC

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/gc/shared/gcTraceSend.cpp:

  void visit(const PSHeapSummary* ps_heap_summary) const {
    visit((GCHeapSummary*)ps_heap_summary);

    const VirtualSpaceSummary& old_summary = ps_heap_summary->old();
    const SpaceSummary& old_space = ps_heap_summary->old_space();
    const VirtualSpaceSummary& young_summary = ps_heap_summary->young();
    const SpaceSummary& eden_space = ps_heap_summary->eden();
    const SpaceSummary& from_space = ps_heap_summary->from();
    const SpaceSummary& to_space = ps_heap_summary->to();

    EventPSHeapSummary e;
    if (e.should_commit()) {
      e.set_gcId(GCId::current());
      e.set_when((u1)_when);

      e.set_oldSpace(to_struct(ps_heap_summary->old()));
      e.set_oldObjectSpace(to_struct(ps_heap_summary->old_space()));
      e.set_youngSpace(to_struct(ps_heap_summary->young()));
      e.set_edenSpace(to_struct(ps_heap_summary->eden()));
      e.set_fromSpace(to_struct(ps_heap_summary->from()));
      e.set_toSpace(to_struct(ps_heap_summary->to()));
      e.commit();

Configuration enabled
default true
profiling true

Field Type Description
gcId uint GC Identifier
when GCWhen When Consider contributing a description to jfreventcollector.
oldSpace VirtualSpace struct Old Space Consider contributing a description to jfreventcollector.
oldObjectSpace ObjectSpace struct Old Object Space Consider contributing a description to jfreventcollector.
youngSpace VirtualSpace struct Young Space Consider contributing a description to jfreventcollector.
edenSpace ObjectSpace struct Eden Space Consider contributing a description to jfreventcollector.
fromSpace ObjectSpace struct From Space Consider contributing a description to jfreventcollector.
toSpace ObjectSpace struct To Space Consider contributing a description to jfreventcollector.

Examples 1
edenSpace ObjectSpace
end ulong: address
33392951296
size ulong: bytes
3328180224
start ulong: address
30064771072
used ulong: bytes
0
fromSpace ObjectSpace
end ulong: address
33555480576
size ulong: bytes
1048576
start ulong: address
33554432000
used ulong: bytes
946384
gcId uint
344
oldObjectSpace ObjectSpace
end ulong: address
23519035392
size ulong: bytes
2044198912
start ulong: address
21474836480
used ulong: bytes
372660984
oldSpace VirtualSpace
committedEnd ulong: address
23519035392
committedSize ulong: bytes
2044198912
reservedEnd ulong: address
30064771072
reservedSize ulong: bytes
8589934592
start ulong: address
21474836480
startTime long: millis
258336442708
toSpace ObjectSpace
end ulong: address
33478410240
size ulong: bytes
77070336
start ulong: address
33401339904
used ulong: bytes
0
when GCWhen
After GC
youngSpace VirtualSpace
committedEnd ulong: address
33555480576
committedSize ulong: bytes
3490709504
reservedEnd ulong: address
34359738368
reservedSize ulong: bytes
4294967296
start ulong: address
30064771072

G1HeapSummary

default profiling startTime 11 17 21 25 26

Category: Java Virtual Machine / GC / Heap

Appearing in: G1GC

Missing in: ParallelGC, SerialGC, ShenandoahGC, ZGC

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/gc/shared/gcTraceSend.cpp:

    EventGCHeapSummary e;
    if (e.should_commit()) {
      e.set_gcId(GCId::current());
      e.set_when((u1)_when);
      e.set_heapSpace(to_struct(heap_space));
      e.set_heapUsed(heap_summary->used());
      e.commit();
    }
  }

  void visit(const G1HeapSummary* g1_heap_summary) const {
    visit((GCHeapSummary*)g1_heap_summary);

    EventG1HeapSummary e;
    if (e.should_commit()) {
      e.set_gcId(GCId::current());
      e.set_when((u1)_when);
      e.set_edenUsedSize(g1_heap_summary->edenUsed());
      e.set_edenTotalSize(g1_heap_summary->edenCapacity());
      e.set_survivorUsedSize(g1_heap_summary->survivorUsed());
      e.set_numberOfRegions(g1_heap_summary->numberOfRegions());
      e.commit();
    }
  }

Configuration enabled
default true
profiling true

Field Type Description
gcId uint GC Identifier
when GCWhen When Consider contributing a description to jfreventcollector.
edenUsedSize ulong: bytes Eden Used Size
edenTotalSize ulong: bytes Eden Total Size
survivorUsedSize ulong: bytes Survivor Used Size
numberOfRegions uint Number of Regions

Examples 1
edenTotalSize ulong: bytes
594852120
edenUsedSize ulong: bytes
0
gcId uint
788
numberOfRegions uint
134
startTime long: millis
202794509166
survivorUsedSize ulong: bytes
739048
when GCWhen
Before GC

JVM: GC: Metaspace

MetaspaceGCThreshold

default profiling startTime 11 17 21 25 26

Category: Java Virtual Machine / GC / Metaspace

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/memory/metaspaceTracer.cpp:

void MetaspaceTracer::report_gc_threshold(size_t old_val,
                                          size_t new_val,
                                          MetaspaceGCThresholdUpdater::Type updater) const {
  EventMetaspaceGCThreshold event;
  if (event.should_commit()) {
    event.set_oldValue(old_val);
    event.set_newValue(new_val);
    event.set_updater((u1)updater);
    event.commit();
  }
}

void MetaspaceTracer::report_metaspace_allocation_failure(ClassLoaderData *cld,
                                                          size_t word_size,
                                                          MetaspaceObj::Type objtype,
                                                          Metaspace::MetadataType mdtype) const {
  send_allocation_failure_event<EventMetaspaceAllocationFailure>(cld, word_size, objtype, mdtype);
}

Configuration enabled
default true
profiling true

Field Type Description
oldValue ulong: bytes Old Value
newValue ulong: bytes New Value
updater GCThresholdUpdater Updater Consider contributing a description to jfreventcollector.

Examples 3
newValue ulong: bytes
1107820544
oldValue ulong: bytes
1107165184
startTime long: millis
254770955167
updater GCThresholdUpdater
compute_new_size
newValue ulong: bytes
1530724352
oldValue ulong: bytes
1493696512
startTime long: millis
244940961958
updater GCThresholdUpdater
compute_new_size
newValue ulong: bytes
1490878464
oldValue ulong: bytes
1484390400
startTime long: millis
263541083917
updater GCThresholdUpdater
compute_new_size

MetaspaceAllocationFailure

default profiling startTime stackTrace 11 17 21 25 26

Category: Java Virtual Machine / GC / Metaspace

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/memory/metaspaceTracer.cpp:

  EventMetaspaceGCThreshold event;
  if (event.should_commit()) {
    event.set_oldValue(old_val);
    event.set_newValue(new_val);
    event.set_updater((u1)updater);
    event.commit();
  }
}

void MetaspaceTracer::report_metaspace_allocation_failure(ClassLoaderData *cld,
                                                          size_t word_size,
                                                          MetaspaceObj::Type objtype,
                                                          Metaspace::MetadataType mdtype) const {
  send_allocation_failure_event<EventMetaspaceAllocationFailure>(cld, word_size, objtype, mdtype);
}

void MetaspaceTracer::report_metadata_oom(ClassLoaderData *cld,
                                         size_t word_size,
                                         MetaspaceObj::Type objtype,
                                         Metaspace::MetadataType mdtype) const {
  send_allocation_failure_event<EventMetaspaceOOM>(cld, word_size, objtype, mdtype);
}

template <typename E>
void MetaspaceTracer::send_allocation_failure_event(ClassLoaderData *cld,

Configuration enabled stackTrace
default true true
profiling true true

Field Type Description
classLoader ClassLoader Class Loader Consider contributing a description to jfreventcollector.
unsafeAnonymousClassLoader boolean until JDK 15 Unsafe Anonymous Class Loader
size ulong: bytes Size
metadataType MetadataType Metadata Type Consider contributing a description to jfreventcollector.
metaspaceObjectType MetaspaceObjectType Metaspace Object Type Consider contributing a description to jfreventcollector.

MetaspaceOOM

default profiling startTime stackTrace 11 17 21 25 26

Category: Java Virtual Machine / GC / Metaspace

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/memory/metaspaceTracer.cpp:

void MetaspaceTracer::report_metaspace_allocation_failure(ClassLoaderData *cld,
                                                          size_t word_size,
                                                          MetaspaceObj::Type objtype,
                                                          Metaspace::MetadataType mdtype) const {
  send_allocation_failure_event<EventMetaspaceAllocationFailure>(cld, word_size, objtype, mdtype);
}

void MetaspaceTracer::report_metadata_oom(ClassLoaderData *cld,
                                         size_t word_size,
                                         MetaspaceObj::Type objtype,
                                         Metaspace::MetadataType mdtype) const {
  send_allocation_failure_event<EventMetaspaceOOM>(cld, word_size, objtype, mdtype);
}

template <typename E>
void MetaspaceTracer::send_allocation_failure_event(ClassLoaderData *cld,
                                                    size_t word_size,
                                                    MetaspaceObj::Type objtype,
                                                    Metaspace::MetadataType mdtype) const {
  E event;
  if (event.should_commit()) {
    event.set_classLoader(cld);
    if (cld->is_unsafe_anonymous()) {

Configuration enabled stackTrace
default true true
profiling true true

Field Type Description
classLoader ClassLoader Class Loader Consider contributing a description to jfreventcollector.
unsafeAnonymousClassLoader boolean until JDK 15 Unsafe Anonymous Class Loader
size ulong: bytes Size
metadataType MetadataType Metadata Type Consider contributing a description to jfreventcollector.
metaspaceObjectType MetaspaceObjectType Metaspace Object Type Consider contributing a description to jfreventcollector.

MetaspaceChunkFreeListSummary

default profiling startTime 11 17 21 25 26

Category: Java Virtual Machine / GC / Metaspace

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/gc/shared/gcTraceSend.cpp:

void GCTracer::send_reference_stats_event(ReferenceType type, size_t count) const {
  EventGCReferenceStatistics e;
  if (e.should_commit()) {
      e.set_gcId(GCId::current());
      e.set_type((u1)type);
      e.set_count(count);
      e.commit();
  }
}

void GCTracer::send_metaspace_chunk_free_list_summary(GCWhen::Type when, Metaspace::MetadataType mdtype,
                                                      const MetaspaceChunkFreeListSummary& summary) const {
  EventMetaspaceChunkFreeListSummary e;
  if (e.should_commit()) {
    e.set_gcId(GCId::current());
    e.set_when(when);
    e.set_metadataType(mdtype);

    e.set_specializedChunks(summary.num_specialized_chunks());
    e.set_specializedChunksTotalSize(summary.specialized_chunks_size_in_bytes());

    e.set_smallChunks(summary.num_small_chunks());
    e.set_smallChunksTotalSize(summary.small_chunks_size_in_bytes());

Configuration enabled
default true
profiling true

Field Type Description
gcId uint GC Identifier
when GCWhen When Consider contributing a description to jfreventcollector.
metadataType MetadataType Metadata Type Consider contributing a description to jfreventcollector.
specializedChunks ulong Specialized Chunks
specializedChunksTotalSize ulong: bytes Specialized Chunks Total Size
smallChunks ulong Small Chunks
smallChunksTotalSize ulong: bytes Small Chunks Total Size
mediumChunks ulong Medium Chunks
mediumChunksTotalSize ulong: bytes Medium Chunks Total Size
humongousChunks ulong Humongous Chunks
humongousChunksTotalSize ulong: bytes Humongous Chunks Total Size

Examples 3
gcId uint
798
humongousChunks ulong
0
humongousChunksTotalSize ulong: bytes
0
mediumChunks ulong
0
mediumChunksTotalSize ulong: bytes
0
metadataType MetadataType
Metadata
smallChunks ulong
0
smallChunksTotalSize ulong: bytes
0
specializedChunks ulong
0
specializedChunksTotalSize ulong: bytes
0
startTime long: millis
214363807958
when GCWhen
After GC
gcId uint
309
humongousChunks ulong
0
humongousChunksTotalSize ulong: bytes
0
mediumChunks ulong
0
mediumChunksTotalSize ulong: bytes
0
metadataType MetadataType
Class
smallChunks ulong
0
smallChunksTotalSize ulong: bytes
0
specializedChunks ulong
0
specializedChunksTotalSize ulong: bytes
0
startTime long: millis
237269860542
when GCWhen
Before GC
gcId uint
729
humongousChunks ulong
0
humongousChunksTotalSize ulong: bytes
0
mediumChunks ulong
0
mediumChunksTotalSize ulong: bytes
0
metadataType MetadataType
Class
smallChunks ulong
0
smallChunksTotalSize ulong: bytes
0
specializedChunks ulong
0
specializedChunksTotalSize ulong: bytes
0
startTime long: millis
265508505917
when GCWhen
Before GC

JVM: GC: Phases

GCPhasePause

default profiling startTime duration eventThread 11 17 21 25 26

Category: Java Virtual Machine / GC / Phases

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/gc/shared/gcTraceSend.cpp:

    e.set_gcThreshold(meta_space_summary.capacity_until_GC());
    e.set_metaspace(to_struct(meta_space_summary.meta_space()));
    e.set_dataSpace(to_struct(meta_space_summary.data_space()));
    e.set_classSpace(to_struct(meta_space_summary.class_space()));
    e.commit();
  }
}

class PhaseSender : public PhaseVisitor {
  void visit_pause(GCPhase* phase) {
    assert(phase->level() < PhasesStack::PHASE_LEVELS, "Need more event types for PausePhase");

    switch (phase->level()) {
      case 0: send_phase<EventGCPhasePause>(phase); break;
      case 1: send_phase<EventGCPhasePauseLevel1>(phase); break;
      case 2: send_phase<EventGCPhasePauseLevel2>(phase); break;
      case 3: send_phase<EventGCPhasePauseLevel3>(phase); break;
      case 4: send_phase<EventGCPhasePauseLevel4>(phase); break;
      default: /* Ignore sending this phase */ break;
    }
  }

  void visit_concurrent(GCPhase* phase) {
    assert(phase->level() < 1, "There is only one level for ConcurrentPhase");

Configuration enabled threshold
default true 0 ms
profiling true 0 ms

Field Type Description
gcId uint GC Identifier
name string Name

Examples 3
gcId uint
321
name string
GC Pause
startTime long: millis
245530981625
gcId uint
799
name string
GC Pause
startTime long: millis
281814097750
gcId uint
819
name string
Pause Cleanup
startTime long: millis
225041142083

GCPhasePauseLevel1

default profiling startTime duration eventThread 11 17 21 25 26

Category: Java Virtual Machine / GC / Phases

Appearing in: G1GC, ParallelGC, SerialGC, ShenandoahGC

Missing in: ZGC

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/gc/shared/gcTraceSend.cpp:

    e.set_metaspace(to_struct(meta_space_summary.meta_space()));
    e.set_dataSpace(to_struct(meta_space_summary.data_space()));
    e.set_classSpace(to_struct(meta_space_summary.class_space()));
    e.commit();
  }
}

class PhaseSender : public PhaseVisitor {
  void visit_pause(GCPhase* phase) {
    assert(phase->level() < PhasesStack::PHASE_LEVELS, "Need more event types for PausePhase");

    switch (phase->level()) {
      case 0: send_phase<EventGCPhasePause>(phase); break;
      case 1: send_phase<EventGCPhasePauseLevel1>(phase); break;
      case 2: send_phase<EventGCPhasePauseLevel2>(phase); break;
      case 3: send_phase<EventGCPhasePauseLevel3>(phase); break;
      case 4: send_phase<EventGCPhasePauseLevel4>(phase); break;
      default: /* Ignore sending this phase */ break;
    }
  }

  void visit_concurrent(GCPhase* phase) {
    assert(phase->level() < 1, "There is only one level for ConcurrentPhase");

    switch (phase->level()) {

Configuration enabled threshold
default true 0 ms
profiling true 0 ms

Field Type Description
gcId uint GC Identifier
name string Name

Examples 3
gcId uint
306
name string
Summary Phase
startTime long: millis
234008511292
gcId uint
726
name string
Notify and keep alive finalizable
startTime long: millis
265315030000
gcId uint
789
name string
Phase 1: Mark live objects
startTime long: millis
203006758541

GCPhasePauseLevel2

default profiling startTime duration eventThread 11 17 21 25 26

Category: Java Virtual Machine / GC / Phases

Appearing in: G1GC, ParallelGC, SerialGC

Missing in: ShenandoahGC, ZGC

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/gc/shared/gcTraceSend.cpp:

    e.set_dataSpace(to_struct(meta_space_summary.data_space()));
    e.set_classSpace(to_struct(meta_space_summary.class_space()));
    e.commit();
  }
}

class PhaseSender : public PhaseVisitor {
  void visit_pause(GCPhase* phase) {
    assert(phase->level() < PhasesStack::PHASE_LEVELS, "Need more event types for PausePhase");

    switch (phase->level()) {
      case 0: send_phase<EventGCPhasePause>(phase); break;
      case 1: send_phase<EventGCPhasePauseLevel1>(phase); break;
      case 2: send_phase<EventGCPhasePauseLevel2>(phase); break;
      case 3: send_phase<EventGCPhasePauseLevel3>(phase); break;
      case 4: send_phase<EventGCPhasePauseLevel4>(phase); break;
      default: /* Ignore sending this phase */ break;
    }
  }

  void visit_concurrent(GCPhase* phase) {
    assert(phase->level() < 1, "There is only one level for ConcurrentPhase");

    switch (phase->level()) {
      case 0: send_phase<EventGCPhaseConcurrent>(phase); break;

Configuration enabled threshold
default true 0 ms
profiling true 0 ms

Field Type Description
gcId uint GC Identifier
name string Name

Examples 3
gcId uint
717
name string
Class Unloading
startTime long: millis
264849136125
gcId uint
802
name string
Phase 1: Class Unloading and Cleanup
startTime long: millis
217963505000
gcId uint
304
name string
Reference Processing
startTime long: millis
233231866333

GCPhasePauseLevel3

startTime duration eventThread 11 17 21 25 26

Category: Java Virtual Machine / GC / Phases

Appearing in: G1GC, ParallelGC, SerialGC

Missing in: ShenandoahGC, ZGC

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/gc/shared/gcTraceSend.cpp:

    e.set_classSpace(to_struct(meta_space_summary.class_space()));
    e.commit();
  }
}

class PhaseSender : public PhaseVisitor {
  void visit_pause(GCPhase* phase) {
    assert(phase->level() < PhasesStack::PHASE_LEVELS, "Need more event types for PausePhase");

    switch (phase->level()) {
      case 0: send_phase<EventGCPhasePause>(phase); break;
      case 1: send_phase<EventGCPhasePauseLevel1>(phase); break;
      case 2: send_phase<EventGCPhasePauseLevel2>(phase); break;
      case 3: send_phase<EventGCPhasePauseLevel3>(phase); break;
      case 4: send_phase<EventGCPhasePauseLevel4>(phase); break;
      default: /* Ignore sending this phase */ break;
    }
  }

  void visit_concurrent(GCPhase* phase) {
    assert(phase->level() < 1, "There is only one level for ConcurrentPhase");

    switch (phase->level()) {
      case 0: send_phase<EventGCPhaseConcurrent>(phase); break;
      default: /* Ignore sending this phase */ break;

Configuration enabled threshold
default false 0 ms
profiling false 0 ms

Field Type Description
gcId uint GC Identifier
name string Name

Examples 3
gcId uint
803
name string
Purge Unlinked NMethods
startTime long: millis
218383361500
gcId uint
714
name string
Purge Unlinked NMethods
startTime long: millis
260878301708
gcId uint
306
name string
Notify PhantomReferences
startTime long: millis
233997198667

GCPhasePauseLevel4

startTime duration eventThread 11 17 21 25 26

Category: Java Virtual Machine / GC / Phases

Appearing in: G1GC, ParallelGC

Missing in: SerialGC, ShenandoahGC, ZGC

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/gc/shared/gcTraceSend.cpp:

    e.commit();
  }
}

class PhaseSender : public PhaseVisitor {
  void visit_pause(GCPhase* phase) {
    assert(phase->level() < PhasesStack::PHASE_LEVELS, "Need more event types for PausePhase");

    switch (phase->level()) {
      case 0: send_phase<EventGCPhasePause>(phase); break;
      case 1: send_phase<EventGCPhasePauseLevel1>(phase); break;
      case 2: send_phase<EventGCPhasePauseLevel2>(phase); break;
      case 3: send_phase<EventGCPhasePauseLevel3>(phase); break;
      case 4: send_phase<EventGCPhasePauseLevel4>(phase); break;
      default: /* Ignore sending this phase */ break;
    }
  }

  void visit_concurrent(GCPhase* phase) {
    assert(phase->level() < 1, "There is only one level for ConcurrentPhase");

    switch (phase->level()) {
      case 0: send_phase<EventGCPhaseConcurrent>(phase); break;
      default: /* Ignore sending this phase */ break;
    }

Configuration enabled threshold
default false 0 ms
profiling false 0 ms

Field Type Description
gcId uint GC Identifier
name string Name

Examples 2
gcId uint
802
name string
Balance queues
startTime long: millis
217963031541
gcId uint
332
name string
Balance queues
startTime long: millis
252982772750

GCPhaseConcurrent

default profiling startTime duration eventThread 11 17 21 25 26

Category: Java Virtual Machine / GC / Phases

Appearing in: G1GC, ShenandoahGC, ZGC

Missing in: ParallelGC, SerialGC

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/gc/shenandoah/shenandoahUtils.hpp:

  ShenandoahWorkerSession(uint worker_id);
  ~ShenandoahWorkerSession();
public:
  static inline uint worker_id() {
    Thread* thr = Thread::current();
    uint id = ShenandoahThreadLocalData::worker_id(thr);
    assert(id != ShenandoahThreadLocalData::INVALID_WORKER_ID, "Worker session has not been created");
    return id;
  }
};

class ShenandoahConcurrentWorkerSession : public ShenandoahWorkerSession {
private:
  EventGCPhaseConcurrent _event;

public:
  ShenandoahConcurrentWorkerSession(uint worker_id) : ShenandoahWorkerSession(worker_id) { }
  ~ShenandoahConcurrentWorkerSession();
};

class ShenandoahParallelWorkerSession : public ShenandoahWorkerSession {
private:
  EventGCPhaseParallel _event;

public:

src/hotspot/share/gc/shared/gcTraceSend.cpp:

      case 0: send_phase<EventGCPhasePause>(phase); break;
      case 1: send_phase<EventGCPhasePauseLevel1>(phase); break;
      case 2: send_phase<EventGCPhasePauseLevel2>(phase); break;
      case 3: send_phase<EventGCPhasePauseLevel3>(phase); break;
      case 4: send_phase<EventGCPhasePauseLevel4>(phase); break;
      default: /* Ignore sending this phase */ break;
    }
  }

  void visit_concurrent(GCPhase* phase) {
    assert(phase->level() < 1, "There is only one level for ConcurrentPhase");

    switch (phase->level()) {
      case 0: send_phase<EventGCPhaseConcurrent>(phase); break;
      default: /* Ignore sending this phase */ break;
    }
  }

 public:
  template<typename T>
  void send_phase(GCPhase* phase) {
    T event(UNTIMED);
    if (event.should_commit()) {
      event.set_gcId(GCId::current());
      event.set_name(phase->name());

Configuration enabled threshold
default true 0 ms
profiling true 0 ms

Field Type Description
gcId uint GC Identifier
name string Name

Examples 3
gcId uint
199
name string
Concurrent Mark Free
startTime long: millis
247000510709
gcId uint
811
name string
Concurrent Clear Claimed Marks
startTime long: millis
224396945666
gcId uint
186
name string
Concurrent weak roots
startTime long: millis
211617080250

GCPhaseParallel

default profiling startTime duration eventThread 12 17 21 25 26

Category: Java Virtual Machine / GC / Phases

Appearing in: G1GC, ShenandoahGC

Missing in: ParallelGC, SerialGC, ZGC

GC phases for parallel workers

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/gc/shenandoah/shenandoahUtils.hpp:

class ShenandoahConcurrentWorkerSession : public ShenandoahWorkerSession {
private:
  EventGCPhaseConcurrent _event;

public:
  ShenandoahConcurrentWorkerSession(uint worker_id) : ShenandoahWorkerSession(worker_id) { }
  ~ShenandoahConcurrentWorkerSession();
};

class ShenandoahParallelWorkerSession : public ShenandoahWorkerSession {
private:
  EventGCPhaseParallel _event;

public:
  ShenandoahParallelWorkerSession(uint worker_id) : ShenandoahWorkerSession(worker_id) { }
  ~ShenandoahParallelWorkerSession();
};

class ShenandoahSuspendibleThreadSetJoiner {
private:
  SuspendibleThreadSetJoiner _joiner;
public:
  ShenandoahSuspendibleThreadSetJoiner(bool active = true) : _joiner(active) {

src/hotspot/share/gc/shenandoah/shenandoahTimingTracker.hpp:

#define SHARE_VM_GC_SHENANDOAH_SHENANDOAHTIMINGTRACKER_HPP

#include "jfr/jfrEvents.hpp"
#include "gc/shenandoah/shenandoahPhaseTimings.hpp"
#include "memory/allocation.hpp"

class ShenandoahWorkerTimingsTracker : public StackObj {
private:
  double _start_time;
  ShenandoahPhaseTimings::GCParPhases _phase;
  ShenandoahWorkerTimings* _worker_times;
  uint _worker_id;

  EventGCPhaseParallel _event;
public:
    ShenandoahWorkerTimingsTracker(ShenandoahWorkerTimings* worker_times, ShenandoahPhaseTimings::GCParPhases phase, uint worker_id);
    ~ShenandoahWorkerTimingsTracker();
};


class ShenandoahTerminationTimingsTracker : public StackObj {
private:
  double _start_time;
  uint   _worker_id;

src/hotspot/share/gc/g1/g1RemSet.cpp:

  _ct->set_card_claimed(card_index);
  _scan_state->add_dirty_region(region_idx_for_card);
}

void G1ScanRSForRegionClosure::scan_card(MemRegion mr, uint region_idx_for_card) {
  HeapRegion* const card_region = _g1h->region_at(region_idx_for_card);
  assert(!card_region->is_young(), "Should not scan card in young region %u", region_idx_for_card);
  card_region->oops_on_card_seq_iterate_careful<true>(mr, _scan_objs_on_card_cl);
  _scan_objs_on_card_cl->trim_queue_partially();
  _cards_scanned++;
}

void G1ScanRSForRegionClosure::scan_rem_set_roots(HeapRegion* r) {
  EventGCPhaseParallel event;
  uint const region_idx = r->hrm_index();

  if (_scan_state->claim_iter(region_idx)) {
    // If we ever free the collection set concurrently, we should also
    // clear the card table concurrently therefore we won't need to
    // add regions of the collection set to the dirty cards region.
    _scan_state->add_dirty_region(region_idx);
  }

  if (r->rem_set()->cardset_is_empty()) {
    return;

src/hotspot/share/gc/g1/g1RemSet.cpp:

    // random cards into current survivor, and we would then have an incorrectly
    // claimed card in survivor space. Card table clear does not reset the card table
    // of survivor space regions.
    claim_card(card_index, region_idx_for_card);

    MemRegion const mr(card_start, MIN2(card_start + BOTConstants::N_words, top));

    scan_card(mr, region_idx_for_card);
  }
  event.commit(GCId::current(), _worker_i, G1GCPhaseTimes::phase_name(_phase));
}

void G1ScanRSForRegionClosure::scan_strong_code_roots(HeapRegion* r) {
  EventGCPhaseParallel event;
  r->strong_code_roots_do(_pss->closures()->weak_codeblobs());
  event.commit(GCId::current(), _worker_i, G1GCPhaseTimes::phase_name(G1GCPhaseTimes::CodeRoots));
}

bool G1ScanRSForRegionClosure::do_heap_region(HeapRegion* r) {
  assert(r->in_collection_set(),
         "Should only be called on elements of the collection set but region %u is not.",
         r->hrm_index());
  uint const region_idx = r->hrm_index();

  // Do an early out if we know we are complete.

src/hotspot/share/gc/g1/g1CollectedHeap.cpp:

  g1_policy()->phase_times()->record_evac_fail_remove_self_forwards((os::elapsedTime() - remove_self_forwards_start) * 1000.0);
}

void G1CollectedHeap::preserve_mark_during_evac_failure(uint worker_id, oop obj, markOop m) {
  if (!_evacuation_failed) {
    _evacuation_failed = true;
  }

  _evacuation_failed_info_array[worker_id].register_copy_failure(obj->size());
  _preserved_marks_set.get(worker_id)->push_if_necessary(obj, m);
}

bool G1ParEvacuateFollowersClosure::offer_termination() {
  EventGCPhaseParallel event;
  G1ParScanThreadState* const pss = par_scan_state();
  start_term_time();
  const bool res = terminator()->offer_termination();
  end_term_time();
  event.commit(GCId::current(), pss->worker_id(), G1GCPhaseTimes::phase_name(G1GCPhaseTimes::Termination));
  return res;
}

void G1ParEvacuateFollowersClosure::do_void() {
  EventGCPhaseParallel event;
  G1ParScanThreadState* const pss = par_scan_state();
  pss->trim_queue();
  event.commit(GCId::current(), pss->worker_id(), G1GCPhaseTimes::phase_name(_phase));
  do {
    EventGCPhaseParallel event;
    pss->steal_and_trim_queue(queues());
    event.commit(GCId::current(), pss->worker_id(), G1GCPhaseTimes::phase_name(_phase));
  } while (!offer_termination());
}

class G1ParTask : public AbstractGangTask {
protected:
  G1CollectedHeap*         _g1h;
  G1ParScanThreadStateSet* _pss;
  RefToScanQueueSet*       _queues;
  G1RootProcessor*         _root_processor;

src/hotspot/share/gc/g1/g1CollectedHeap.cpp:

    double young_time = 0.0;
    bool has_young_time = false;
    double non_young_time = 0.0;
    bool has_non_young_time = false;

    while (true) {
      size_t end = Atomic::add(chunk_size(), &_parallel_work_claim);
      size_t cur = end - chunk_size();

      if (cur >= _num_work_items) {
        break;
      }

      EventGCPhaseParallel event;
      double start_time = os::elapsedTime();

      end = MIN2(end, _num_work_items);

      for (; cur < end; cur++) {
        bool is_young = _work_items[cur].is_young;

        do_parallel_work_for_region(_work_items[cur].region_idx, is_young, _work_items[cur].evacuation_failed);

        double end_time = os::elapsedTime();
        double time_taken = end_time - start_time;

src/hotspot/share/gc/g1/g1GCPhaseTimes.hpp:

public:
  G1EvacPhaseWithTrimTimeTracker(G1ParScanThreadState* pss, Tickspan& total_time, Tickspan& trim_time);
  ~G1EvacPhaseWithTrimTimeTracker();

  void stop();
};

class G1GCParPhaseTimesTracker : public CHeapObj<mtGC> {
protected:
  Ticks _start_time;
  G1GCPhaseTimes::GCParPhases _phase;
  G1GCPhaseTimes* _phase_times;
  uint _worker_id;
  EventGCPhaseParallel _event;
public:
  G1GCParPhaseTimesTracker(G1GCPhaseTimes* phase_times, G1GCPhaseTimes::GCParPhases phase, uint worker_id);
  virtual ~G1GCParPhaseTimesTracker();
};

class G1EvacPhaseTimesTracker : public G1GCParPhaseTimesTracker {
  Tickspan _total_time;
  Tickspan _trim_time;

  G1EvacPhaseWithTrimTimeTracker _trim_tracker;
public:

Configuration enabled threshold
default true 0 ms
profiling true 0 ms

Field Type Description
gcId uint GC Identifier
gcWorkerId uint GC Worker Identifier
name string Name

Examples 2
gcId uint
194
gcWorkerId uint
2
name string
Finish Mark
startTime long: millis
233574873125
gcId uint
778
gcWorkerId uint
2
name string
ObjCopy
startTime long: millis
199113495250

JVM: GC: Reference

GCReferenceStatistics

default profiling startTime 11 17 21 25 26

Category: Java Virtual Machine / GC / Reference

Total count of processed references during GC

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/gc/shared/gcTraceSend.cpp:

  if (event.should_commit()) {
    event.set_gcId(GCId::current());
    event.set_name(_shared_gc_info.name());
    event.set_cause((u2) _shared_gc_info.cause());
    event.set_sumOfPauses(_shared_gc_info.sum_of_pauses());
    event.set_longestPause(_shared_gc_info.longest_pause());
    event.set_starttime(_shared_gc_info.start_timestamp());
    event.set_endtime(_shared_gc_info.end_timestamp());
    event.commit();
  }
}

void GCTracer::send_reference_stats_event(ReferenceType type, size_t count) const {
  EventGCReferenceStatistics e;
  if (e.should_commit()) {
      e.set_gcId(GCId::current());
      e.set_type((u1)type);
      e.set_count(count);
      e.commit();
  }
}

void GCTracer::send_metaspace_chunk_free_list_summary(GCWhen::Type when, Metaspace::MetadataType mdtype,
                                                      const MetaspaceChunkFreeListSummary& summary) const {
  EventMetaspaceChunkFreeListSummary e;

Configuration enabled
default true
profiling true

Field Type Description
gcId uint GC Identifier
type ReferenceType Type Consider contributing a description to jfreventcollector.
count ulong Total Count

Examples 3
count ulong
0
gcId uint
724
startTime long: millis
265205855792
type ReferenceType
Phantom reference
count ulong
0
gcId uint
297
startTime long: millis
230211038208
type ReferenceType
Final reference
count ulong
0
gcId uint
780
startTime long: millis
199145142500
type ReferenceType
Soft reference

JVM: Profiling

OldObjectSample

cutoff default profiling startTime eventThread stackTrace 11 17 21 25 26

Category: Java Virtual Machine / Profiling

A potential memory leak

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/jfr/leakprofiler/sampling/objectSampler.cpp:

  const traceid thread_id = thread->threadObj() != NULL ? thread->jfr_thread_local()->thread_id() : 0;
  if (thread_id == 0) {
    return;
  }
  assert(thread_id != 0, "invariant");

  if (!thread->jfr_thread_local()->has_thread_checkpoint()) {
    JfrCheckpointManager::create_thread_checkpoint(thread);
    assert(thread->jfr_thread_local()->has_thread_checkpoint(), "invariant");
  }

  traceid stack_trace_id = 0;
  unsigned int stack_trace_hash = 0;
  if (JfrEventSetting::has_stacktrace(EventOldObjectSample::eventId)) {
    stack_trace_id = JfrStackTraceRepository::record(thread, 0, &stack_trace_hash);
    thread->jfr_thread_local()->set_cached_stack_trace_id(stack_trace_id, stack_trace_hash);
  }

  JfrTryLock tryLock(&_tryLock);
  if (!tryLock.has_lock()) {
    log_trace(jfr, oldobject, sampling)("Skipping old object sample due to lock contention");
    return;
  }

  if (_dead_samples) {

src/hotspot/share/jfr/leakprofiler/emitEventOperation.cpp:

    // we need to register a top level edge for this object
    Edge e(NULL, object_addr);
    edge_store->add_chain(&e, 1);
    edge = (const Edge*)(*object_addr)->mark();
  } else {
    gc_root_id = edge_store->get_root_id(edge);
  }

  assert(edge != NULL, "invariant");
  assert(edge->pointee() == *object_addr, "invariant");
  const traceid object_id = edge_store->get_id(edge);
  assert(object_id != 0, "invariant");

  EventOldObjectSample e(UNTIMED);
  e.set_starttime(GranularTimer::start_time());
  e.set_endtime(GranularTimer::end_time());
  e.set_allocationTime(sample->allocation_time());
  e.set_lastKnownHeapUsage(sample->heap_used_at_last_gc());
  e.set_object(object_id);
  e.set_arrayElements(array_size(*object_addr));
  e.set_root(gc_root_id);

  // Temporarily assigning both the stack trace id and thread id
  // onto the thread local data structure of the VMThread (for the duration
  // of the commit() call). This trick provides a means to override

src/hotspot/share/jfr/jni/jfrJniMethod.cpp:

NO_TRANSITION(jlong, jfr_elapsed_counter(JNIEnv* env, jobject jvm))
  return JfrTicks::now();
NO_TRANSITION_END

NO_TRANSITION(void, jfr_retransform_classes(JNIEnv* env, jobject jvm, jobjectArray classes))
  JfrJvmtiAgent::retransform_classes(env, classes, JavaThread::thread_from_jni_environment(env));
NO_TRANSITION_END

NO_TRANSITION(void, jfr_set_enabled(JNIEnv* env, jobject jvm, jlong event_type_id, jboolean enabled))
  JfrEventSetting::set_enabled(event_type_id, JNI_TRUE == enabled);
  if (EventOldObjectSample::eventId == event_type_id) {
    ThreadInVMfromNative transition(JavaThread::thread_from_jni_environment(env));
    if (JNI_TRUE == enabled) {
      LeakProfiler::start(JfrOptionSet::old_object_queue_size());
    } else {
      LeakProfiler::stop();
    }
  }
NO_TRANSITION_END

NO_TRANSITION(void, jfr_set_file_notification(JNIEnv* env, jobject jvm, jlong threshold))
  JfrChunkRotation::set_threshold(threshold);

Configuration cutoff enabled stackTrace
default 0 ns true false
profiling 0 ns true true

Field Type Description
allocationTime Ticks Allocation Time Consider contributing a description to jfreventcollector.
lastKnownHeapUsage ulong: bytes Last Known Heap Usage
object OldObject Object Consider contributing a description to jfreventcollector.
arrayElements int Array Elements If the object is an array, the number of elements, or -1 if it is not an array
root OldObjectGcRoot GC Root Consider contributing a description to jfreventcollector.

Examples 3
allocationTime Ticks
218316691167
arrayElements int
-2147483648
lastKnownHeapUsage ulong: bytes
227589096
object OldObject
address ulong: address
25969620872
description string
null
referrer Reference
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
17
name string
java/lang/invoke/MethodType
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/lang/invoke
root OldObjectGcRoot
null
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
11
lineNumber int
400
method Method
descriptor string
(Ljava/lang/Class;[Ljava/lang/Class;Z)Ljava/lang/invoke/MethodType;
hidden boolean
false
modifiers int
10
name string
makeImpl
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
17
name string
java/lang/invoke/MethodType
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/lang/invoke
type FrameType
Inlined
truncated boolean
false
startTime long: millis
294457260833
allocationTime Ticks
33406287292
arrayElements int
-2147483648
lastKnownHeapUsage ulong: bytes
46919864
object OldObject
address ulong: address
21520598200
description string
Class Name: com.twitter.chill.java.Java8ClosureRegistrar
referrer Reference
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
17
name string
java/lang/Class
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/lang
root OldObjectGcRoot
null
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
0
lineNumber int
-1
method Method
descriptor string
(Ljava/lang/ClassLoader;Ljava/lang/String;[BIILjava/security/ProtectionDomain;Ljava/lang/String;)Ljava/lang/Class;
hidden boolean
false
modifiers int
264
name string
defineClass1
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1025
name string
java/lang/ClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/lang
type FrameType
Native
truncated boolean
false
startTime long: millis
271918712542
allocationTime Ticks
249331056208
arrayElements int
64
lastKnownHeapUsage ulong: bytes
277607048
object OldObject
address ulong: address
21771390872
description string
null
referrer Reference
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1041
name string
[Ljava/util/concurrent/ForkJoinTask;
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/util/concurrent
root OldObjectGcRoot
null
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
32
lineNumber int
1607
method Method
descriptor string
(Ljava/util/concurrent/ForkJoinPool$WorkQueue;)V
hidden boolean
false
modifiers int
16
name string
registerWorker
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/util/concurrent/ForkJoinPool
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/util/concurrent
type FrameType
Interpreted
truncated boolean
false
startTime long: millis
253457007166

ExecutionSample

default profiling startTime every chunk 11 17 21 25 26

Category: Java Virtual Machine / Profiling

Snapshot of a threads state

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/jfr/jni/jfrJniMethod.cpp:

JVM_ENTRY_NO_ENV(void, jfr_subscribe_log_level(JNIEnv* env, jobject jvm, jobject log_tag, jint id))
  JfrJavaLog::subscribe_log_level(log_tag, id, thread);
JVM_END

JVM_ENTRY_NO_ENV(void, jfr_set_output(JNIEnv* env, jobject jvm, jstring path))
  JfrRepository::set_chunk_path(path, thread);
JVM_END

JVM_ENTRY_NO_ENV(void, jfr_set_method_sampling_interval(JNIEnv* env, jobject jvm, jlong type, jlong intervalMillis))
  if (intervalMillis < 0) {
    intervalMillis = 0;
  }
  JfrEventId typed_event_id = (JfrEventId)type;
  assert(EventExecutionSample::eventId == typed_event_id || EventNativeMethodSample::eventId == typed_event_id, "invariant");
  if (intervalMillis > 0) {
    JfrEventSetting::set_enabled(typed_event_id, true); // ensure sampling event is enabled
  }
  if (EventExecutionSample::eventId == type) {
    JfrThreadSampling::set_java_sample_interval(intervalMillis);
  } else {
    JfrThreadSampling::set_native_sample_interval(intervalMillis);
  }
JVM_END

JVM_ENTRY_NO_ENV(void, jfr_store_metadata_descriptor(JNIEnv* env, jobject jvm, jbyteArray descriptor))
  JfrMetadataEvent::update(descriptor);
JVM_END

// trace thread id for a thread object

src/hotspot/share/jfr/periodic/sampling/jfrThreadSampler.cpp:

    case _thread_in_native_trans:
      break;
    case _thread_in_native:
      return true;
    default:
      ShouldNotReachHere();
      break;
  }
  return false;
}

class JfrThreadSampleClosure {
 public:
  JfrThreadSampleClosure(EventExecutionSample* events, EventNativeMethodSample* events_native);
  ~JfrThreadSampleClosure() {}
  EventExecutionSample* next_event() { return &_events[_added_java++]; }
  EventNativeMethodSample* next_event_native() { return &_events_native[_added_native++]; }
  void commit_events(JfrSampleType type);
  bool do_sample_thread(JavaThread* thread, JfrStackFrame* frames, u4 max_frames, JfrSampleType type);
  uint java_entries() { return _added_java; }
  uint native_entries() { return _added_native; }

 private:
  bool sample_thread_in_java(JavaThread* thread, JfrStackFrame* frames, u4 max_frames);
  bool sample_thread_in_native(JavaThread* thread, JfrStackFrame* frames, u4 max_frames);
  EventExecutionSample* _events;
  EventNativeMethodSample* _events_native;
  Thread* _self;
  uint _added_java;
  uint _added_native;
};

class OSThreadSampler : public os::SuspendedThreadTask {
 public:
  OSThreadSampler(JavaThread* thread,
                  JfrThreadSampleClosure& closure,
                  JfrStackFrame *frames,

src/hotspot/share/jfr/periodic/sampling/jfrThreadSampler.cpp:

  // Skip sample if we signaled a thread that moved to other state
  if (!thread_state_in_java(jth)) {
    return;
  }
  JfrGetCallTrace trace(true, jth);
  frame topframe;
  if (trace.get_topframe(context.ucontext(), topframe)) {
    if (_stacktrace.record_thread(*jth, topframe)) {
      /* If we managed to get a topframe and a stacktrace, create an event
      * and put it into our array. We can't call Jfr::_stacktraces.add()
      * here since it would allocate memory using malloc. Doing so while
      * the stopped thread is inside malloc would deadlock. */
      _success = true;
      EventExecutionSample *ev = _closure.next_event();
      ev->set_starttime(_suspend_time);
      ev->set_endtime(_suspend_time); // fake to not take an end time
      ev->set_sampledThread(JFR_THREAD_ID(jth));
      ev->set_state(java_lang_Thread::get_thread_status(jth->threadObj()));
    }
  }
}

void OSThreadSampler::take_sample() {
  run();
}

src/hotspot/share/jfr/periodic/sampling/jfrThreadSampler.cpp:

bool JfrThreadSampleClosure::sample_thread_in_java(JavaThread* thread, JfrStackFrame* frames, u4 max_frames) {
  OSThreadSampler sampler(thread, *this, frames, max_frames);
  sampler.take_sample();
  /* We don't want to allocate any memory using malloc/etc while the thread
  * is stopped, so everything is stored in stack allocated memory until this
  * point where the thread has been resumed again, if the sampling was a success
  * we need to store the stacktrace in the stacktrace repository and update
  * the event with the id that was returned. */
  if (!sampler.success()) {
    return false;
  }
  EventExecutionSample *event = &_events[_added_java - 1];
  traceid id = JfrStackTraceRepository::add(sampler.stacktrace());
  assert(id != 0, "Stacktrace id should not be 0");
  event->set_stackTrace(id);
  return true;
}

bool JfrThreadSampleClosure::sample_thread_in_native(JavaThread* thread, JfrStackFrame* frames, u4 max_frames) {
  JfrNativeSamplerCallback cb(*this, thread, frames, max_frames);
  if (JfrOptionSet::sample_protection()) {
    os::ThreadCrashProtection crash_protection;
    if (!crash_protection.call(cb)) {

src/hotspot/share/jfr/periodic/sampling/jfrThreadSampler.cpp:

    assert(_added_java > 0 && _added_java <= MAX_NR_OF_JAVA_SAMPLES, "invariant");
    for (uint i = 0; i < _added_java; ++i) {
      _events[i].commit();
    }
  } else {
    assert(NATIVE_SAMPLE == type, "invariant");
    assert(_added_native > 0 && _added_native <= MAX_NR_OF_NATIVE_SAMPLES, "invariant");
    for (uint i = 0; i < _added_native; ++i) {
      _events_native[i].commit();
    }
  }
}

JfrThreadSampleClosure::JfrThreadSampleClosure(EventExecutionSample* events, EventNativeMethodSample* events_native) :
  _events(events),
  _events_native(events_native),
  _self(Thread::current()),
  _added_java(0),
  _added_native(0) {
}

class JfrThreadSampler : public NonJavaThread {
  friend class JfrThreadSampling;
 private:
  Semaphore _sample;

src/hotspot/share/jfr/periodic/sampling/jfrThreadSampler.cpp:

      last_java_ms = get_monotonic_ms();
    }
    if ((next_n - sleep_to_next) <= 0) {
      task_stacktrace(NATIVE_SAMPLE, &_last_thread_native);
      last_native_ms = get_monotonic_ms();
    }
  }
  delete this;
}


void JfrThreadSampler::task_stacktrace(JfrSampleType type, JavaThread** last_thread) {
  ResourceMark rm;
  EventExecutionSample samples[MAX_NR_OF_JAVA_SAMPLES];
  EventNativeMethodSample samples_native[MAX_NR_OF_NATIVE_SAMPLES];
  JfrThreadSampleClosure sample_task(samples, samples_native);

  const uint sample_limit = JAVA_SAMPLE == type ? MAX_NR_OF_JAVA_SAMPLES : MAX_NR_OF_NATIVE_SAMPLES;
  uint num_samples = 0;
  JavaThread* start = NULL;

  {
    elapsedTimer sample_time;
    sample_time.start();
    {

Configuration enabled period
default true 20 ms
profiling true 10 ms

Field Type Description
sampledThread Thread Thread Consider contributing a description to jfreventcollector.
stackTrace StackTrace Stack Trace Consider contributing a description to jfreventcollector.
state ThreadState Thread State

Examples 3
sampledThread Thread
group ThreadGroup
name string
main
parent ThreadGroup
name string
system
parent ThreadGroup
null
javaName string
Executor task launch worker for task 2.0 in stage 22.0 (TID 157)
javaThreadId long
1581
osName string
Executor task launch worker for task 2.0 in stage 22.0 (TID 157)
osThreadId long
118547
virtual boolean
false
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
258
lineNumber int
-1
method Method
descriptor string
(Ljava/lang/String;ID[DII[DI)V
hidden boolean
false
modifiers int
9
name string
dspr
type Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/net
hidden boolean
false
modifiers int
17
name string
org/netlib/blas/Dspr
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/net
location string
null
name string
null
version string
null
name string
org/netlib/blas
type FrameType
JIT compiled
truncated boolean
false
startTime long: millis
219722587250
state ThreadState
STATE_RUNNABLE
sampledThread Thread
group ThreadGroup
name string
main
parent ThreadGroup
name string
system
parent ThreadGroup
null
javaName string
Executor task launch worker for task 4.0 in stage 26.0 (TID 199)
javaThreadId long
1556
osName string
Executor task launch worker for task 4.0 in stage 26.0 (TID 199)
osThreadId long
147991
virtual boolean
false
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
70
lineNumber int
443
method Method
descriptor string
(Ljava/lang/Object;Ljava/lang/Object;)Ljava/lang/Object;
hidden boolean
false
modifiers int
1
name string
put
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/util/IdentityHashMap
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/util
type FrameType
Inlined
truncated boolean
false
startTime long: millis
254462843958
state ThreadState
STATE_RUNNABLE
sampledThread Thread
group ThreadGroup
name string
main
parent ThreadGroup
name string
system
parent ThreadGroup
null
javaName string
Executor task launch worker for task 0.0 in stage 20.0 (TID 135)
javaThreadId long
1568
osName string
Executor task launch worker for task 0.0 in stage 20.0 (TID 135)
osThreadId long
50447
virtual boolean
false
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
13
lineNumber int
3440
method Method
descriptor string
(Ljava/lang/String;ID[DII[DI)V
hidden boolean
false
modifiers int
4
name string
dsprK
type Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/net
hidden boolean
false
modifiers int
0
name string
dev/ludovic/netlib/blas/Java8BLAS
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/net
location string
null
name string
null
version string
null
name string
dev/ludovic/netlib/blas
type FrameType
Inlined
truncated boolean
false
startTime long: millis
242308768208
state ThreadState
STATE_RUNNABLE

NativeMethodSample

default profiling startTime every chunk 11 17 21 25 26

Category: Java Virtual Machine / Profiling

Snapshot of a threads state when in native

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/jfr/jni/jfrJniMethod.cpp:

JVM_ENTRY_NO_ENV(void, jfr_subscribe_log_level(JNIEnv* env, jobject jvm, jobject log_tag, jint id))
  JfrJavaLog::subscribe_log_level(log_tag, id, thread);
JVM_END

JVM_ENTRY_NO_ENV(void, jfr_set_output(JNIEnv* env, jobject jvm, jstring path))
  JfrRepository::set_chunk_path(path, thread);
JVM_END

JVM_ENTRY_NO_ENV(void, jfr_set_method_sampling_interval(JNIEnv* env, jobject jvm, jlong type, jlong intervalMillis))
  if (intervalMillis < 0) {
    intervalMillis = 0;
  }
  JfrEventId typed_event_id = (JfrEventId)type;
  assert(EventExecutionSample::eventId == typed_event_id || EventNativeMethodSample::eventId == typed_event_id, "invariant");
  if (intervalMillis > 0) {
    JfrEventSetting::set_enabled(typed_event_id, true); // ensure sampling event is enabled
  }
  if (EventExecutionSample::eventId == type) {
    JfrThreadSampling::set_java_sample_interval(intervalMillis);
  } else {
    JfrThreadSampling::set_native_sample_interval(intervalMillis);
  }
JVM_END

JVM_ENTRY_NO_ENV(void, jfr_store_metadata_descriptor(JNIEnv* env, jobject jvm, jbyteArray descriptor))

src/hotspot/share/jfr/periodic/sampling/jfrThreadSampler.cpp:

    case _thread_in_native_trans:
      break;
    case _thread_in_native:
      return true;
    default:
      ShouldNotReachHere();
      break;
  }
  return false;
}

class JfrThreadSampleClosure {
 public:
  JfrThreadSampleClosure(EventExecutionSample* events, EventNativeMethodSample* events_native);
  ~JfrThreadSampleClosure() {}
  EventExecutionSample* next_event() { return &_events[_added_java++]; }
  EventNativeMethodSample* next_event_native() { return &_events_native[_added_native++]; }
  void commit_events(JfrSampleType type);
  bool do_sample_thread(JavaThread* thread, JfrStackFrame* frames, u4 max_frames, JfrSampleType type);
  uint java_entries() { return _added_java; }
  uint native_entries() { return _added_native; }

 private:
  bool sample_thread_in_java(JavaThread* thread, JfrStackFrame* frames, u4 max_frames);
  bool sample_thread_in_native(JavaThread* thread, JfrStackFrame* frames, u4 max_frames);
  EventExecutionSample* _events;
  EventNativeMethodSample* _events_native;
  Thread* _self;
  uint _added_java;
  uint _added_native;
};

class OSThreadSampler : public os::SuspendedThreadTask {
 public:
  OSThreadSampler(JavaThread* thread,
                  JfrThreadSampleClosure& closure,
                  JfrStackFrame *frames,
                  u4 max_frames) : os::SuspendedThreadTask((Thread*)thread),

src/hotspot/share/jfr/periodic/sampling/jfrThreadSampler.cpp:

  virtual void call();
  bool success() { return _success; }
  JfrStackTrace& stacktrace() { return _stacktrace; }

 private:
  JfrThreadSampleClosure& _closure;
  JavaThread* _jt;
  JfrStackTrace _stacktrace;
  bool _success;
};

static void write_native_event(JfrThreadSampleClosure& closure, JavaThread* jt) {
  EventNativeMethodSample *ev = closure.next_event_native();
  ev->set_starttime(JfrTicks::now());
  ev->set_sampledThread(JFR_THREAD_ID(jt));
  ev->set_state(java_lang_Thread::get_thread_status(jt->threadObj()));
}

void JfrNativeSamplerCallback::call() {
  // When a thread is only attach it will be native without a last java frame
  if (!_jt->has_last_Java_frame()) {
    return;
  }

src/hotspot/share/jfr/periodic/sampling/jfrThreadSampler.cpp:

bool JfrThreadSampleClosure::sample_thread_in_native(JavaThread* thread, JfrStackFrame* frames, u4 max_frames) {
  JfrNativeSamplerCallback cb(*this, thread, frames, max_frames);
  if (JfrOptionSet::sample_protection()) {
    os::ThreadCrashProtection crash_protection;
    if (!crash_protection.call(cb)) {
      log_error(jfr)("Thread method sampler crashed for native");
    }
  } else {
    cb.call();
  }
  if (!cb.success()) {
    return false;
  }
  EventNativeMethodSample *event = &_events_native[_added_native - 1];
  traceid id = JfrStackTraceRepository::add(cb.stacktrace());
  assert(id != 0, "Stacktrace id should not be 0");
  event->set_stackTrace(id);
  return true;
}

static const uint MAX_NR_OF_JAVA_SAMPLES = 5;
static const uint MAX_NR_OF_NATIVE_SAMPLES = 1;

void JfrThreadSampleClosure::commit_events(JfrSampleType type) {
  if (JAVA_SAMPLE == type) {

src/hotspot/share/jfr/periodic/sampling/jfrThreadSampler.cpp:

    assert(_added_java > 0 && _added_java <= MAX_NR_OF_JAVA_SAMPLES, "invariant");
    for (uint i = 0; i < _added_java; ++i) {
      _events[i].commit();
    }
  } else {
    assert(NATIVE_SAMPLE == type, "invariant");
    assert(_added_native > 0 && _added_native <= MAX_NR_OF_NATIVE_SAMPLES, "invariant");
    for (uint i = 0; i < _added_native; ++i) {
      _events_native[i].commit();
    }
  }
}

JfrThreadSampleClosure::JfrThreadSampleClosure(EventExecutionSample* events, EventNativeMethodSample* events_native) :
  _events(events),
  _events_native(events_native),
  _self(Thread::current()),
  _added_java(0),
  _added_native(0) {
}

class JfrThreadSampler : public NonJavaThread {
  friend class JfrThreadSampling;
 private:
  Semaphore _sample;

src/hotspot/share/jfr/periodic/sampling/jfrThreadSampler.cpp:

    if ((next_n - sleep_to_next) <= 0) {
      task_stacktrace(NATIVE_SAMPLE, &_last_thread_native);
      last_native_ms = get_monotonic_ms();
    }
  }
  delete this;
}


void JfrThreadSampler::task_stacktrace(JfrSampleType type, JavaThread** last_thread) {
  ResourceMark rm;
  EventExecutionSample samples[MAX_NR_OF_JAVA_SAMPLES];
  EventNativeMethodSample samples_native[MAX_NR_OF_NATIVE_SAMPLES];
  JfrThreadSampleClosure sample_task(samples, samples_native);

  const uint sample_limit = JAVA_SAMPLE == type ? MAX_NR_OF_JAVA_SAMPLES : MAX_NR_OF_NATIVE_SAMPLES;
  uint num_samples = 0;
  JavaThread* start = NULL;

  {
    elapsedTimer sample_time;
    sample_time.start();
    {
      MonitorLockerEx tlock(Threads_lock, Mutex::_allow_vm_block_flag);

Configuration enabled period
default true 20 ms
profiling true 10 ms

Field Type Description
sampledThread Thread Thread Consider contributing a description to jfreventcollector.
stackTrace StackTrace Stack Trace Consider contributing a description to jfreventcollector.
state ThreadState Thread State

Examples 3
sampledThread Thread
group ThreadGroup
name string
main
parent ThreadGroup
name string
system
parent ThreadGroup
null
javaName string
SparkUI-1530
javaThreadId long
1530
osName string
SparkUI-1530
osThreadId long
34603
virtual boolean
false
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
0
lineNumber int
-1
method Method
descriptor string
(IJIJ)I
hidden boolean
false
modifiers int
264
name string
poll
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
0
name string
sun/nio/ch/KQueue
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
sun/nio/ch
type FrameType
Native
truncated boolean
false
startTime long: millis
242800482875
state ThreadState
STATE_RUNNABLE
sampledThread Thread
group ThreadGroup
name string
finagle/netty4
parent ThreadGroup
name string
main
parent ThreadGroup
name string
system
parent ThreadGroup
null
javaName string
finagle/netty4-2-6
javaThreadId long
1210
osName string
finagle/netty4-2-6
osThreadId long
100875
virtual boolean
false
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
0
lineNumber int
-1
method Method
descriptor string
(IJIJ)I
hidden boolean
false
modifiers int
264
name string
poll
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
0
name string
sun/nio/ch/KQueue
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
sun/nio/ch
type FrameType
Native
truncated boolean
false
startTime long: millis
229968814667
state ThreadState
STATE_RUNNABLE
sampledThread Thread
group ThreadGroup
name string
finagle/netty4
parent ThreadGroup
name string
main
parent ThreadGroup
name string
system
parent ThreadGroup
null
javaName string
finagle/netty4-2-5
javaThreadId long
1211
osName string
finagle/netty4-2-5
osThreadId long
130595
virtual boolean
false
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
0
lineNumber int
-1
method Method
descriptor string
(IJIJ)I
hidden boolean
false
modifiers int
264
name string
poll
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
0
name string
sun/nio/ch/KQueue
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
sun/nio/ch
type FrameType
Native
truncated boolean
false
startTime long: millis
199802515333
state ThreadState
STATE_RUNNABLE

JVM: Runtime

BiasedLockRevocation

default profiling startTime duration eventThread stackTrace 11 17 until JDK 18

Category: Java Virtual Machine / Runtime

Revoked bias of object

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/runtime/biasedLocking.cpp:

  assert(event != NULL, "invariant");
  // Subtract 1 to match the id of events committed inside the safepoint
  event->set_safepointId(SafepointSynchronize::safepoint_counter() - 1);
}

static void post_self_revocation_event(EventBiasedLockSelfRevocation* event, Klass* k) {
  assert(event != NULL, "invariant");
  assert(k != NULL, "invariant");
  assert(event->should_commit(), "invariant");
  event->set_lockClass(k);
  event->commit();
}

static void post_revocation_event(EventBiasedLockRevocation* event, Klass* k, VM_RevokeBias* revoke) {
  assert(event != NULL, "invariant");
  assert(k != NULL, "invariant");
  assert(revoke != NULL, "invariant");
  assert(event->should_commit(), "invariant");
  event->set_lockClass(k);
  set_safepoint_id(event);
  event->set_previousOwner(revoke->biased_locker());
  event->commit();
}

static void post_class_revocation_event(EventBiasedLockClassRevocation* event, Klass* k, bool disabled_bias) {

src/hotspot/share/runtime/biasedLocking.cpp:

      // can come in with a CAS to steal the bias of an object that has a
      // stale epoch.
      ResourceMark rm;
      log_info(biasedlocking)("Revoking bias by walking my own stack:");
      EventBiasedLockSelfRevocation event;
      BiasedLocking::Condition cond = revoke_bias(obj(), false, false, (JavaThread*) THREAD, NULL);
      ((JavaThread*) THREAD)->set_cached_monitor_info(NULL);
      assert(cond == BIAS_REVOKED, "why not?");
      if (event.should_commit()) {
        post_self_revocation_event(&event, k);
      }
      return cond;
    } else {
      EventBiasedLockRevocation event;
      VM_RevokeBias revoke(&obj, (JavaThread*) THREAD);
      VMThread::execute(&revoke);
      if (event.should_commit() && revoke.status_code() != NOT_BIASED) {
        post_revocation_event(&event, k, &revoke);
      }
      return revoke.status_code();
    }
  }

  assert((heuristics == HR_BULK_REVOKE) ||
         (heuristics == HR_BULK_REBIAS), "?");

Configuration enabled stackTrace threshold
default true true 0 ms
profiling true true 0 ms

Field Type Description
lockClass Class Lock Class Class of object whose biased lock was revoked
safepointId ulong Safepoint Identifier
previousOwner Thread Previous Owner Thread owning the bias before revocation

BiasedLockSelfRevocation

default profiling startTime duration eventThread stackTrace 11 17 until JDK 18

Category: Java Virtual Machine / Runtime

Revoked bias of object biased towards own thread

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/runtime/biasedLocking.cpp:

  virtual void doit() {
    _status_code = bulk_revoke_or_rebias_at_safepoint((*_obj)(), _bulk_rebias, _attempt_rebias_of_object, _requesting_thread);
    clean_up_cached_monitor_info();
  }
};

template <typename E>
static void set_safepoint_id(E* event) {
  assert(event != NULL, "invariant");
  // Subtract 1 to match the id of events committed inside the safepoint
  event->set_safepointId(SafepointSynchronize::safepoint_counter() - 1);
}

static void post_self_revocation_event(EventBiasedLockSelfRevocation* event, Klass* k) {
  assert(event != NULL, "invariant");
  assert(k != NULL, "invariant");
  assert(event->should_commit(), "invariant");
  event->set_lockClass(k);
  event->commit();
}

static void post_revocation_event(EventBiasedLockRevocation* event, Klass* k, VM_RevokeBias* revoke) {
  assert(event != NULL, "invariant");
  assert(k != NULL, "invariant");
  assert(revoke != NULL, "invariant");

src/hotspot/share/runtime/biasedLocking.cpp:

    if (mark->biased_locker() == THREAD &&
        prototype_header->bias_epoch() == mark->bias_epoch()) {
      // A thread is trying to revoke the bias of an object biased
      // toward it, again likely due to an identity hash code
      // computation. We can again avoid a safepoint in this case
      // since we are only going to walk our own stack. There are no
      // races with revocations occurring in other threads because we
      // reach no safepoints in the revocation path.
      // Also check the epoch because even if threads match, another thread
      // can come in with a CAS to steal the bias of an object that has a
      // stale epoch.
      ResourceMark rm;
      log_info(biasedlocking)("Revoking bias by walking my own stack:");
      EventBiasedLockSelfRevocation event;
      BiasedLocking::Condition cond = revoke_bias(obj(), false, false, (JavaThread*) THREAD, NULL);
      ((JavaThread*) THREAD)->set_cached_monitor_info(NULL);
      assert(cond == BIAS_REVOKED, "why not?");
      if (event.should_commit()) {
        post_self_revocation_event(&event, k);
      }
      return cond;
    } else {
      EventBiasedLockRevocation event;
      VM_RevokeBias revoke(&obj, (JavaThread*) THREAD);
      VMThread::execute(&revoke);

Configuration enabled stackTrace threshold
default true true 0 ms
profiling true true 0 ms

Field Type Description
lockClass Class Lock Class Class of object whose biased lock was revoked

BiasedLockClassRevocation

default profiling startTime duration eventThread stackTrace 11 17 until JDK 18

Category: Java Virtual Machine / Runtime

Revoked biases for all instances of a class

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/runtime/biasedLocking.cpp:

static void post_revocation_event(EventBiasedLockRevocation* event, Klass* k, VM_RevokeBias* revoke) {
  assert(event != NULL, "invariant");
  assert(k != NULL, "invariant");
  assert(revoke != NULL, "invariant");
  assert(event->should_commit(), "invariant");
  event->set_lockClass(k);
  set_safepoint_id(event);
  event->set_previousOwner(revoke->biased_locker());
  event->commit();
}

static void post_class_revocation_event(EventBiasedLockClassRevocation* event, Klass* k, bool disabled_bias) {
  assert(event != NULL, "invariant");
  assert(k != NULL, "invariant");
  assert(event->should_commit(), "invariant");
  event->set_revokedClass(k);
  event->set_disableBiasing(disabled_bias);
  set_safepoint_id(event);
  event->commit();
}

BiasedLocking::Condition BiasedLocking::revoke_and_rebias(Handle obj, bool attempt_rebias, TRAPS) {
  assert(!SafepointSynchronize::is_at_safepoint(), "must not be called while at safepoint");

src/hotspot/share/runtime/biasedLocking.cpp:

    } else {
      EventBiasedLockRevocation event;
      VM_RevokeBias revoke(&obj, (JavaThread*) THREAD);
      VMThread::execute(&revoke);
      if (event.should_commit() && revoke.status_code() != NOT_BIASED) {
        post_revocation_event(&event, k, &revoke);
      }
      return revoke.status_code();
    }
  }

  assert((heuristics == HR_BULK_REVOKE) ||
         (heuristics == HR_BULK_REBIAS), "?");
  EventBiasedLockClassRevocation event;
  VM_BulkRevokeBias bulk_revoke(&obj, (JavaThread*) THREAD,
                                (heuristics == HR_BULK_REBIAS),
                                attempt_rebias);
  VMThread::execute(&bulk_revoke);
  if (event.should_commit()) {
    post_class_revocation_event(&event, obj->klass(), heuristics != HR_BULK_REBIAS);
  }
  return bulk_revoke.status_code();
}

Configuration enabled stackTrace threshold
default true true 0 ms
profiling true true 0 ms

Field Type Description
revokedClass Class Revoked Class Class whose biased locks were revoked
disableBiasing boolean Disable Further Biasing Whether further biasing for instances of this class will be allowed
safepointId ulong Safepoint Identifier

ReservedStackActivation

default profiling startTime eventThread stackTrace 11 17 21 25 26

Category: Java Virtual Machine / Runtime

Activation of Reserved Stack Area caused by stack overflow with ReservedStackAccess annotated method in call stack

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/runtime/sharedRuntime.cpp:

        for (ScopeDesc *sd = nm->scope_desc_near(fr.pc()); sd != NULL; sd = sd->sender()) {
          method = sd->method();
          if (method != NULL && method->has_reserved_stack_access()) {
            found = true;
      }
    }
      }
    }
    if (found) {
      activation = fr;
      warning("Potentially dangerous stack overflow in "
              "ReservedStackAccess annotated method %s [%d]",
              method->name_and_sig_as_C_string(), count++);
      EventReservedStackActivation event;
      if (event.should_commit()) {
        event.set_method(method);
        event.commit();
      }
    }
    if (fr.is_first_java_frame()) {
      break;
    } else {
      fr = fr.java_sender();
    }
  }

Configuration enabled stackTrace
default true true
profiling true true

Field Type Description
method Method Java Method

SafepointBegin

default profiling startTime duration eventThread 11 17 21 25 26

Category: Java Virtual Machine / Runtime / Safepoint

Safepointing begin

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/runtime/safepoint.cpp:

#ifdef COMPILER1
#include "c1/c1_globals.hpp"
#endif

template <typename E>
static void set_current_safepoint_id(E* event, int adjustment = 0) {
  assert(event != NULL, "invariant");
  event->set_safepointId(SafepointSynchronize::safepoint_counter() + adjustment);
}

static void post_safepoint_begin_event(EventSafepointBegin* event,
                                       int thread_count,
                                       int critical_thread_count) {
  assert(event != NULL, "invariant");
  assert(event->should_commit(), "invariant");
  set_current_safepoint_id(event);
  event->set_totalThreadCount(thread_count);
  event->set_jniCriticalThreadCount(critical_thread_count);
  event->commit();
}

static void post_safepoint_cleanup_event(EventSafepointCleanup* event) {

src/hotspot/share/runtime/safepoint.cpp:

static volatile int PageArmed = 0 ;        // safepoint polling page is RO|RW vs PROT_NONE
static volatile int TryingToBlock = 0 ;    // proximate value -- for advisory use only
static bool timeout_error_printed = false;


// Statistic related statics
julong SafepointSynchronize::_coalesced_vmop_count = 0;
static jlong _safepoint_begin_time = 0;
static float _ts_of_current_safepoint = 0.0f;
static volatile int _nof_threads_hit_polling_page = 0;

// Roll all threads forward to a safepoint and suspend them all
void SafepointSynchronize::begin() {
  EventSafepointBegin begin_event;
  Thread* myThread = Thread::current();
  assert(myThread->is_VM_thread(), "Only VM thread may execute a safepoint");

  if (log_is_enabled(Debug, safepoint, stats)) {
    _safepoint_begin_time = os::javaTimeNanos();
    _ts_of_current_safepoint = tty->time_stamp().seconds();
    _nof_threads_hit_polling_page = 0;
  }

  Universe::heap()->safepoint_synchronize_begin();

Configuration enabled threshold
default true 10 ms
profiling true 0 ms

Field Type Description
safepointId ulong Safepoint Identifier
totalThreadCount int Total Threads The total number of threads at the start of safe point
jniCriticalThreadCount int JNI Critical Threads The number of threads in JNI critical sections

Examples 3
jniCriticalThreadCount int
0
safepointId ulong
1805
startTime long: millis
224560481625
totalThreadCount int
133
jniCriticalThreadCount int
0
safepointId ulong
1458
startTime long: millis
266680061500
totalThreadCount int
100
jniCriticalThreadCount int
0
safepointId ulong
1007
startTime long: millis
253686186542
totalThreadCount int
158

SafepointStateSynchronization

startTime duration eventThread 11 17 21 25 26

Category: Java Virtual Machine / Runtime / Safepoint

Synchronize run state of threads

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/runtime/safepoint.cpp:

  set_current_safepoint_id(event);
  event->set_totalThreadCount(thread_count);
  event->set_jniCriticalThreadCount(critical_thread_count);
  event->commit();
}

static void post_safepoint_cleanup_event(EventSafepointCleanup* event) {
  assert(event != NULL, "invariant");
  assert(event->should_commit(), "invariant");
  set_current_safepoint_id(event);
  event->commit();
}

static void post_safepoint_synchronize_event(EventSafepointStateSynchronization* event,
                                             int initial_number_of_threads,
                                             int threads_waiting_to_block,
                                             unsigned int iterations) {
  assert(event != NULL, "invariant");
  if (event->should_commit()) {
    // Group this event together with the ones committed after the counter is increased
    set_current_safepoint_id(event, 1);
    event->set_initialThreadCount(initial_number_of_threads);
    event->set_runningThreadCount(threads_waiting_to_block);
    event->set_iterations(iterations);
    event->commit();

src/hotspot/share/runtime/safepoint.cpp:

  //     the VM thread issues a memory barrier instruction.
  //  3. Running compiled Code
  //     Compiled code reads a global (Safepoint Polling) page that
  //     is set to fault if we are trying to get to a safepoint.
  //  4. Blocked
  //     A thread which is blocked will not be allowed to return from the
  //     block condition until the safepoint operation is complete.
  //  5. In VM or Transitioning between states
  //     If a Java thread is currently running in the VM or transitioning
  //     between states, the safepointing code will wait for the thread to
  //     block itself when it attempts transitions to a new state.
  //
  {
    EventSafepointStateSynchronization sync_event;
    int initial_running = 0;

    _state            = _synchronizing;

    if (SafepointMechanism::uses_thread_local_poll()) {
      // Arming the per thread poll while having _state != _not_synchronized means safepointing
      log_trace(safepoint)("Setting thread local yield flag for threads");
      OrderAccess::storestore(); // storestore, global state -> local state
      for (JavaThreadIteratorWithHandle jtiwh; JavaThread *cur = jtiwh.next(); ) {
        // Make sure the threads start polling, it is time to yield.
        SafepointMechanism::arm_local_poll(cur);

Configuration enabled threshold
default false 10 ms
profiling false 0 ms

Field Type Description
safepointId ulong Safepoint Identifier
initialThreadCount int Initial Threads The number of threads running at the beginning of state check
runningThreadCount int Running Threads The number of threads still running
iterations int Iterations Number of state check iterations

Examples 3
initialThreadCount int
5
iterations int
3
runningThreadCount int
0
safepointId ulong
1461
startTime long: millis
267647495750
initialThreadCount int
10
iterations int
4
runningThreadCount int
0
safepointId ulong
1778
startTime long: millis
218891159958
initialThreadCount int
1
iterations int
2
runningThreadCount int
0
safepointId ulong
965
startTime long: millis
242749634917

SafepointWaitBlocked

startTime duration eventThread 11 until JDK 13

Category: Java Virtual Machine / Runtime / Safepoint

Safepointing begin waiting on running threads to block

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/runtime/safepoint.cpp:

                                             int threads_waiting_to_block,
                                             unsigned int iterations) {
  assert(event != NULL, "invariant");
  if (event->should_commit()) {
    // Group this event together with the ones committed after the counter is increased
    set_current_safepoint_id(event, 1);
    event->set_initialThreadCount(initial_number_of_threads);
    event->set_runningThreadCount(threads_waiting_to_block);
    event->set_iterations(iterations);
    event->commit();
  }
}

static void post_safepoint_wait_blocked_event(EventSafepointWaitBlocked* event,
                                              int initial_threads_waiting_to_block) {
  assert(event != NULL, "invariant");
  assert(event->should_commit(), "invariant");
  set_current_safepoint_id(event);
  event->set_runningThreadCount(initial_threads_waiting_to_block);
  event->commit();
}

static void post_safepoint_cleanup_task_event(EventSafepointCleanupTask* event,
                                              const char* name) {
  assert(event != NULL, "invariant");

src/hotspot/share/runtime/safepoint.cpp:

    } // ThreadsListHandle destroyed here.
    assert(still_running == 0, "sanity check");

    if (log_is_enabled(Debug, safepoint, stats)) {
      update_statistics_on_spin_end();
    }
    if (sync_event.should_commit()) {
      post_safepoint_synchronize_event(&sync_event, initial_running, _waiting_to_block, iterations);
    }
  }

  // wait until all threads are stopped
  {
    EventSafepointWaitBlocked wait_blocked_event;
    int initial_waiting_to_block = _waiting_to_block;

    while (_waiting_to_block > 0) {
      log_debug(safepoint)("Waiting for %d thread(s) to block", _waiting_to_block);
      if (!SafepointTimeout || timeout_error_printed) {
        Safepoint_lock->wait(true);  // true, means with no safepoint checks
      } else {
        // Compute remaining time
        jlong remaining_time = safepoint_limit_time - os::javaTimeNanos();

        // If there is no remaining time, then there is an error

Configuration enabled threshold
default false 10 ms
profiling false 0 ms

Field Type Description
safepointId ulong Safepoint Identifier
runningThreadCount int Running Threads The number running of threads wait for safe point

SafepointCleanup

startTime duration eventThread 11 17 21 until JDK 23

Category: Java Virtual Machine / Runtime / Safepoint

Safepointing begin running cleanup tasks

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/runtime/safepoint.cpp:

static void post_safepoint_begin_event(EventSafepointBegin* event,
                                       int thread_count,
                                       int critical_thread_count) {
  assert(event != NULL, "invariant");
  assert(event->should_commit(), "invariant");
  set_current_safepoint_id(event);
  event->set_totalThreadCount(thread_count);
  event->set_jniCriticalThreadCount(critical_thread_count);
  event->commit();
}

static void post_safepoint_cleanup_event(EventSafepointCleanup* event) {
  assert(event != NULL, "invariant");
  assert(event->should_commit(), "invariant");
  set_current_safepoint_id(event);
  event->commit();
}

static void post_safepoint_synchronize_event(EventSafepointStateSynchronization* event,
                                             int initial_number_of_threads,
                                             int threads_waiting_to_block,
                                             unsigned int iterations) {
  assert(event != NULL, "invariant");

src/hotspot/share/runtime/safepoint.cpp:

  // Update the count of active JNI critical regions
  GCLocker::set_jni_lock_count(_current_jni_active_count);

  log_info(safepoint)("Entering safepoint region: %s", VMThread::vm_safepoint_description());

  RuntimeService::record_safepoint_synchronized();
  if (log_is_enabled(Debug, safepoint, stats)) {
    update_statistics_on_sync_end(os::javaTimeNanos());
  }

  // Call stuff that needs to be run when a safepoint is just about to be completed
  {
    EventSafepointCleanup cleanup_event;
    do_cleanup_tasks();
    if (cleanup_event.should_commit()) {
      post_safepoint_cleanup_event(&cleanup_event);
    }
  }

  if (log_is_enabled(Debug, safepoint, stats)) {
    // Record how much time spend on the above cleanup tasks
    update_statistics_on_cleanup_end(os::javaTimeNanos());
  }

Configuration enabled threshold
default false 10 ms
profiling false 0 ms

Field Type Description
safepointId ulong Safepoint Identifier

Examples 3
safepointId ulong
1762
startTime long: millis
214423042750
safepointId ulong
1014
startTime long: millis
253780560667
safepointId ulong
1459
startTime long: millis
266837945083

SafepointCleanupTask

startTime duration eventThread 11 17 21 until JDK 23

Category: Java Virtual Machine / Runtime / Safepoint

Safepointing begin running cleanup tasks

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/runtime/safepoint.cpp:

    event->commit();
  }
}

static void post_safepoint_wait_blocked_event(EventSafepointWaitBlocked* event,
                                              int initial_threads_waiting_to_block) {
  assert(event != NULL, "invariant");
  assert(event->should_commit(), "invariant");
  set_current_safepoint_id(event);
  event->set_runningThreadCount(initial_threads_waiting_to_block);
  event->commit();
}

static void post_safepoint_cleanup_task_event(EventSafepointCleanupTask* event,
                                              const char* name) {
  assert(event != NULL, "invariant");
  if (event->should_commit()) {
    set_current_safepoint_id(event);
    event->set_name(name);
    event->commit();
  }
}

static void post_safepoint_end_event(EventSafepointEnd* event) {
  assert(event != NULL, "invariant");

src/hotspot/share/runtime/safepoint.cpp:

  ParallelSPCleanupTask(uint num_workers, DeflateMonitorCounters* counters) :
    AbstractGangTask("Parallel Safepoint Cleanup"),
    _subtasks(SubTasksDone(SafepointSynchronize::SAFEPOINT_CLEANUP_NUM_TASKS)),
    _cleanup_threads_cl(ParallelSPCleanupThreadClosure(counters)),
    _num_workers(num_workers),
    _counters(counters) {}

  void work(uint worker_id) {
    // All threads deflate monitors and mark nmethods (if necessary).
    Threads::possibly_parallel_threads_do(true, &_cleanup_threads_cl);

    if (_subtasks.try_claim_task(SafepointSynchronize::SAFEPOINT_CLEANUP_DEFLATE_MONITORS)) {
      const char* name = "deflating global idle monitors";
      EventSafepointCleanupTask event;
      TraceTime timer(name, TRACETIME_LOG(Info, safepoint, cleanup));
      ObjectSynchronizer::deflate_idle_monitors(_counters);
      if (event.should_commit()) {
        post_safepoint_cleanup_task_event(&event, name);
      }
    }

    if (_subtasks.try_claim_task(SafepointSynchronize::SAFEPOINT_CLEANUP_UPDATE_INLINE_CACHES)) {
      const char* name = "updating inline caches";
      EventSafepointCleanupTask event;
      TraceTime timer(name, TRACETIME_LOG(Info, safepoint, cleanup));
      InlineCacheBuffer::update_inline_caches();
      if (event.should_commit()) {
        post_safepoint_cleanup_task_event(&event, name);
      }
    }

    if (_subtasks.try_claim_task(SafepointSynchronize::SAFEPOINT_CLEANUP_COMPILATION_POLICY)) {
      const char* name = "compilation policy safepoint handler";
      EventSafepointCleanupTask event;
      TraceTime timer(name, TRACETIME_LOG(Info, safepoint, cleanup));
      CompilationPolicy::policy()->do_safepoint_work();
      if (event.should_commit()) {
        post_safepoint_cleanup_task_event(&event, name);
      }
    }

    if (_subtasks.try_claim_task(SafepointSynchronize::SAFEPOINT_CLEANUP_SYMBOL_TABLE_REHASH)) {
      if (SymbolTable::needs_rehashing()) {
        const char* name = "rehashing symbol table";
        EventSafepointCleanupTask event;
        TraceTime timer(name, TRACETIME_LOG(Info, safepoint, cleanup));
        SymbolTable::rehash_table();
        if (event.should_commit()) {
          post_safepoint_cleanup_task_event(&event, name);
        }
      }
    }

    if (_subtasks.try_claim_task(SafepointSynchronize::SAFEPOINT_CLEANUP_STRING_TABLE_REHASH)) {
      if (StringTable::needs_rehashing()) {
        const char* name = "rehashing string table";
        EventSafepointCleanupTask event;
        TraceTime timer(name, TRACETIME_LOG(Info, safepoint, cleanup));
        StringTable::rehash_table();
        if (event.should_commit()) {
          post_safepoint_cleanup_task_event(&event, name);
        }
      }
    }

    if (_subtasks.try_claim_task(SafepointSynchronize::SAFEPOINT_CLEANUP_CLD_PURGE)) {
      // CMS delays purging the CLDG until the beginning of the next safepoint and to
      // make sure concurrent sweep is done
      const char* name = "purging class loader data graph";
      EventSafepointCleanupTask event;
      TraceTime timer(name, TRACETIME_LOG(Info, safepoint, cleanup));
      ClassLoaderDataGraph::purge_if_needed();
      if (event.should_commit()) {
        post_safepoint_cleanup_task_event(&event, name);
      }
    }

    if (_subtasks.try_claim_task(SafepointSynchronize::SAFEPOINT_CLEANUP_SYSTEM_DICTIONARY_RESIZE)) {
      const char* name = "resizing system dictionaries";
      EventSafepointCleanupTask event;
      TraceTime timer(name, TRACETIME_LOG(Info, safepoint, cleanup));
      ClassLoaderDataGraph::resize_if_needed();
      if (event.should_commit()) {
        post_safepoint_cleanup_task_event(&event, name);
      }
    }

    _subtasks.all_tasks_completed(_num_workers);
  }
};

Configuration enabled threshold
default false 10 ms
profiling false 0 ms

Field Type Description
safepointId ulong Safepoint Identifier
name string Task Name The task name

Examples 3
name string
updating inline caches
safepointId ulong
1777
startTime long: millis
218865821000
name string
updating inline caches
safepointId ulong
1476
startTime long: millis
272172889042
name string
updating inline caches
safepointId ulong
1031
startTime long: millis
254169179750

SafepointEnd

startTime duration eventThread 11 17 21 25 26

Category: Java Virtual Machine / Runtime / Safepoint

Safepointing end

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/runtime/safepoint.cpp:

  event->commit();
}

static void post_safepoint_cleanup_task_event(EventSafepointCleanupTask* event,
                                              const char* name) {
  assert(event != NULL, "invariant");
  if (event->should_commit()) {
    set_current_safepoint_id(event);
    event->set_name(name);
    event->commit();
  }
}

static void post_safepoint_end_event(EventSafepointEnd* event) {
  assert(event != NULL, "invariant");
  if (event->should_commit()) {
    // Group this event together with the ones committed before the counter increased
    set_current_safepoint_id(event, -1);
    event->commit();
  }
}

// --------------------------------------------------------------------------------------------------
// Implementation of Safepoint begin/end

src/hotspot/share/runtime/safepoint.cpp:

    update_statistics_on_cleanup_end(os::javaTimeNanos());
  }

  if (begin_event.should_commit()) {
    post_safepoint_begin_event(&begin_event, nof_threads, _current_jni_active_count);
  }
}

// Wake up all threads, so they are ready to resume execution after the safepoint
// operation has been carried out
void SafepointSynchronize::end() {
  assert(Threads_lock->owned_by_self(), "must hold Threads_lock");
  assert((_safepoint_counter & 0x1) == 1, "must be odd");
  EventSafepointEnd event;
  _safepoint_counter ++;
  // memory fence isn't required here since an odd _safepoint_counter
  // value can do no harm and a fence is issued below anyway.

  DEBUG_ONLY(Thread* myThread = Thread::current();)
  assert(myThread->is_VM_thread(), "Only VM thread can execute a safepoint");

  if (log_is_enabled(Debug, safepoint, stats)) {
    end_statistics(os::javaTimeNanos());
  }

Configuration enabled threshold
default false 10 ms
profiling false 0 ms

Field Type Description
safepointId ulong Safepoint Identifier

Examples 3
safepointId ulong
1458
startTime long: millis
266722012833
safepointId ulong
1783
startTime long: millis
220017469916
safepointId ulong
1030
startTime long: millis
254169038167

ExecuteVMOperation

default profiling startTime duration eventThread 11 17 21 25 26

Category: Java Virtual Machine / Runtime

Execution of a VM Operation

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/runtime/vmThread.cpp:

  // otherwise we will hang, since there is no one can end the safepoint.

  // Wait until VM thread is terminated
  // Note: it should be OK to use Terminator_lock here. But this is called
  // at a very delicate time (VM shutdown) and we are operating in non- VM
  // thread at Safepoint. It's safer to not share lock with other threads.
  { MutexLockerEx ml(_terminate_lock, Mutex::_no_safepoint_check_flag);
    while(!VMThread::is_terminated()) {
        _terminate_lock->wait(Mutex::_no_safepoint_check_flag);
    }
  }
}

static void post_vm_operation_event(EventExecuteVMOperation* event, VM_Operation* op) {
  assert(event != NULL, "invariant");
  assert(event->should_commit(), "invariant");
  assert(op != NULL, "invariant");
  const bool is_concurrent = op->evaluate_concurrently();
  const bool evaluate_at_safepoint = op->evaluate_at_safepoint();
  event->set_operation(op->type());
  event->set_safepoint(evaluate_at_safepoint);
  event->set_blocking(!is_concurrent);
  // Only write caller thread information for non-concurrent vm operations.
  // For concurrent vm operations, the thread id is set to 0 indicating thread is unknown.
  // This is because the caller thread could have exited already.

src/hotspot/share/runtime/vmThread.cpp:

  event->set_safepointId(evaluate_at_safepoint ? SafepointSynchronize::safepoint_counter() : 0);
  event->commit();
}

void VMThread::evaluate_operation(VM_Operation* op) {
  ResourceMark rm;

  {
    PerfTraceTime vm_op_timer(perf_accumulated_vm_operation_time());
    HOTSPOT_VMOPS_BEGIN(
                     (char *) op->name(), strlen(op->name()),
                     op->evaluation_mode());

    EventExecuteVMOperation event;
    op->evaluate();
    if (event.should_commit()) {
      post_vm_operation_event(&event, op);
    }

    HOTSPOT_VMOPS_END(
                     (char *) op->name(), strlen(op->name()),
                     op->evaluation_mode());
  }

  // Last access of info in _cur_vm_operation!

Configuration enabled threshold
default true 10 ms
profiling true 0 ms

Field Type Description
operation VMOperationType Operation Consider contributing a description to jfreventcollector.
safepoint boolean At Safepoint If the operation occured at a safepoint
blocking boolean Caller Blocked If the calling thread was blocked until the operation was complete
caller Thread Caller Thread requesting operation. If non-blocking, will be set to 0 indicating thread is unknown
safepointId ulong Safepoint Identifier The safepoint (if any) under which this operation was completed

Examples 3
blocking boolean
true
caller Thread
group ThreadGroup
name string
main
parent ThreadGroup
name string
system
parent ThreadGroup
null
javaName string
JFR Periodic Tasks
javaThreadId long
20
osName string
JFR Periodic Tasks
osThreadId long
32771
virtual boolean
false
operation VMOperationType
ClassLoaderStatsOperation
safepoint boolean
true
safepointId ulong
1739
startTime long: millis
202995281333
blocking boolean
true
caller Thread
group ThreadGroup
name string
main
parent ThreadGroup
name string
system
parent ThreadGroup
null
javaName string
main
javaThreadId long
1
osName string
main
osThreadId long
5123
virtual boolean
false
operation VMOperationType
GenCollectFull
safepoint boolean
true
safepointId ulong
1459
startTime long: millis
266837956125
blocking boolean
true
caller Thread
group ThreadGroup
name string
main
parent ThreadGroup
name string
system
parent ThreadGroup
null
javaName string
main
javaThreadId long
1
osName string
main
osThreadId long
5635
virtual boolean
false
operation VMOperationType
HandshakeAllThreads
safepoint boolean
false
safepointId ulong
0
startTime long: millis
244736335917

Shutdown

default profiling startTime eventThread stackTrace 11 17 21 25 26

Category: Java Virtual Machine / Runtime

JVM shutting down

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/prims/jvm.cpp:

  HandleMark hm(THREAD);
  const char* temp_dir = os::get_temp_directory();
  Handle h = java_lang_String::create_from_platform_dependent_str(temp_dir, CHECK_NULL);
  return (jstring) JNIHandles::make_local(env, h());
JVM_END


// java.lang.Runtime /////////////////////////////////////////////////////////////////////////

extern volatile jint vm_created;

JVM_ENTRY_NO_ENV(void, JVM_BeforeHalt())
  JVMWrapper("JVM_BeforeHalt");
  EventShutdown event;
  if (event.should_commit()) {
    event.set_reason("Shutdown requested from Java");
    event.commit();
  }
JVM_END


JVM_ENTRY_NO_ENV(void, JVM_Halt(jint code))
  before_exit(thread);
  vm_exit(code);
JVM_END

src/hotspot/share/utilities/vmError.cpp:

      show_message_box(buffer, sizeof(buffer));

      // User has asked JVM to abort. Reset ShowMessageBoxOnError so the
      // WatcherThread can kill JVM if the error handler hangs.
      ShowMessageBoxOnError = false;
    }

    os::check_dump_limit(buffer, sizeof(buffer));

    // reset signal handlers or exception filter; make sure recursive crashes
    // are handled properly.
    reset_signal_handlers();

    EventShutdown e;
    if (e.should_commit()) {
      e.set_reason("VM Error");
      e.commit();
    }

    JFR_ONLY(Jfr::on_vm_shutdown(true);)

  } else {
    // If UseOsErrorReporting we call this for each level of the call stack
    // while searching for the exception handler.  Only the first level needs
    // to be reported.

src/hotspot/share/runtime/thread.cpp:

#ifdef ASSERT
  _vm_complete = false;
#endif
  // Wait until we are the last non-daemon thread to execute
  { MutexLocker nu(Threads_lock);
    while (Threads::number_of_non_daemon_threads() > 1)
      // This wait should make safepoint checks, wait without a timeout,
      // and wait as a suspend-equivalent condition.
      Threads_lock->wait(!Mutex::_no_safepoint_check_flag, 0,
                         Mutex::_as_suspend_equivalent_flag);
  }

  EventShutdown e;
  if (e.should_commit()) {
    e.set_reason("No remaining non-daemon Java threads");
    e.commit();
  }

  // Hang forever on exit if we are reporting an error.
  if (ShowMessageBoxOnError && VMError::is_error_reported()) {
    os::infinite_sleep();
  }
  os::wait_for_keypress_at_exit();

Configuration enabled stackTrace
default true true
profiling true true

Field Type Description
reason string Reason Reason for JVM shutdown

Examples 3
reason string
No remaining non-daemon Java threads
stackTrace StackTrace
null
startTime long: millis
271918480958
reason string
No remaining non-daemon Java threads
stackTrace StackTrace
null
startTime long: millis
294456948250
reason string
No remaining non-daemon Java threads
stackTrace StackTrace
null
startTime long: millis
253456608458

ThreadDump

default profiling startTime duration every chunk 11 17 21 25 26

Category: Java Virtual Machine / Runtime

Appearing in: ParallelGC

Missing in: G1GC, SerialGC, ShenandoahGC, ZGC

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/jfr/periodic/jfrPeriodic.cpp:

/*
 * This is left empty on purpose, having ExecutionSample as a requestable
 * is a way of getting the period. The period is passed to ThreadSampling::update_period.
 * Implementation in jfrSamples.cpp
 */
TRACE_REQUEST_FUNC(ExecutionSample) {
}
TRACE_REQUEST_FUNC(NativeMethodSample) {
}

TRACE_REQUEST_FUNC(ThreadDump) {
  ResourceMark rm;
  EventThreadDump event;
  event.set_result(JfrDcmdEvent::thread_dump());
  event.commit();
}

static int _native_library_callback(const char* name, address base, address top, void *param) {
  EventNativeLibrary event(UNTIMED);
  event.set_name(name);
  event.set_baseAddress((u8)base);
  event.set_topAddress((u8)top);
  event.set_endtime(*(JfrTicks*) param);
  event.commit();

src/hotspot/share/jfr/periodic/jfrThreadDumpEvent.cpp:

  Thread* THREAD = Thread::current();
  assert(!HAS_PENDING_EXCEPTION, "dcmd does not expect pending exceptions on entry!");
  // delegate to DCmd execution
  DCmd::parse_and_execute(DCmd_Source_Internal, &st, cmd, ' ', THREAD);
  if (HAS_PENDING_EXCEPTION) {
    log_debug(jfr, system)("unable to create jfr event for DCMD %s", cmd);
    log_debug(jfr, system)("exception type: %s", PENDING_EXCEPTION->klass()->external_name());
    // don't unwind this exception
    CLEAR_PENDING_EXCEPTION;
    // if exception occurred,
    // reset stream.
    st.reset();
    return false;
  }
  return true;
}

// caller needs ResourceMark
const char* JfrDcmdEvent::thread_dump() {
  assert(EventThreadDump::is_enabled(), "invariant");
  bufferedStream st;
  execute_dcmd(st, "Thread.print");
  return st.as_string();
}

Configuration enabled period
default true everyChunk
profiling true 60 s

Field Type Description
result string Thread Dump

Examples 1
result string
2025-08-11 13:13:10 Full thread dump OpenJDK 64-Bit Server VM (21.0.7+6-LTS mixed mode, sharing): Threads class SMR info: _java_thread_list=0x0000600000a55b00, length=296, elements={ 0x000000012d008600, 0x000000012c01b200, 0x000000012c018800, 0x000000012b811400, 0x000000012b811c00, 0x000000012b8124
startTime long: millis
242286191375

NativeLibrary

default profiling startTime every chunk 11 17 21 25 26

Category: Java Virtual Machine / Runtime

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/jfr/periodic/jfrPeriodic.cpp:

TRACE_REQUEST_FUNC(ExecutionSample) {
}
TRACE_REQUEST_FUNC(NativeMethodSample) {
}

TRACE_REQUEST_FUNC(ThreadDump) {
  ResourceMark rm;
  EventThreadDump event;
  event.set_result(JfrDcmdEvent::thread_dump());
  event.commit();
}

static int _native_library_callback(const char* name, address base, address top, void *param) {
  EventNativeLibrary event(UNTIMED);
  event.set_name(name);
  event.set_baseAddress((u8)base);
  event.set_topAddress((u8)top);
  event.set_endtime(*(JfrTicks*) param);
  event.commit();
  return 0;
}

TRACE_REQUEST_FUNC(NativeLibrary) {
  JfrTicks ts= JfrTicks::now();
  os::get_loaded_modules_info(&_native_library_callback, (void *)&ts);

Configuration enabled period
default true everyChunk
profiling true everyChunk

Field Type Description
name string Name
baseAddress ulong: address Base Address Starting address of the module
topAddress ulong: address Top Address Ending address of the module

Examples 3
baseAddress ulong: address
10564730880
name string
/usr/lib/swift/libswiftObservation.dylib
startTime long: millis
199126906250
topAddress ulong: address
0
baseAddress ulong: address
6811627520
name string
/System/Library/PrivateFrameworks/CoreAnalytics.framework/Versions/A/CoreAnalytics
startTime long: millis
230210233625
topAddress ulong: address
0
baseAddress ulong: address
7026069504
name string
/System/Library/Frameworks/Carbon.framework/Versions/A/Frameworks/SpeechRecognition.framework/Versions/A/SpeechRecognition
startTime long: millis
242226700042
topAddress ulong: address
0

ModuleRequire

default profiling startTime every chunk 11 17 21 25 26

Category: Java Virtual Machine / Runtime / Modules

A directed edge representing a dependency

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/jfr/periodic/jfrModuleEvent.cpp:

   ModuleDependencyClosure(const ModuleEntry* module, EventFunc ef) : ModuleEventCallbackClosure(ef), _module(module) {}
   void do_module(ModuleEntry* entry);
};

class ModuleExportClosure : public ModuleEventCallbackClosure {
 private:
  const PackageEntry* const _package;
 public:
  ModuleExportClosure(const PackageEntry* pkg, EventFunc ef) : ModuleEventCallbackClosure(ef), _package(pkg) {}
  void do_module(ModuleEntry* entry);
};

static void write_module_dependency_event(const void* from_module, const ModuleEntry* to_module) {
  EventModuleRequire event(UNTIMED);
  event.set_endtime(invocation_time);
  event.set_source((const ModuleEntry* const)from_module);
  event.set_requiredModule(to_module);
  event.commit();
}

static void write_module_export_event(const void* package, const ModuleEntry* qualified_export) {
  EventModuleExport event(UNTIMED);
  event.set_endtime(invocation_time);
  event.set_exportedPackage((const PackageEntry*)package);
  event.set_targetModule(qualified_export);

Configuration enabled period
default true endChunk
profiling true endChunk

Field Type Description
source Module Source Module
requiredModule Module Required Module Consider contributing a description to jfreventcollector.

Examples 3
requiredModule Module
classLoader ClassLoader
name string
platform
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
10
name string
jdk/internal/loader/ClassLoaders$PlatformClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
jdk/internal/loader
location string
jrt:/java.transaction.xa
name string
java.transaction.xa
version string
21.0.7
source Module
classLoader ClassLoader
name string
platform
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
10
name string
jdk/internal/loader/ClassLoaders$PlatformClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
jdk/internal/loader
location string
jrt:/java.sql.rowset
name string
java.sql.rowset
version string
21.0.7
startTime long: millis
243809184667
requiredModule Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
source Module
classLoader ClassLoader
name string
platform
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
10
name string
jdk/internal/loader/ClassLoaders$PlatformClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
jdk/internal/loader
location string
jrt:/java.smartcardio
name string
java.smartcardio
version string
21.0.7
startTime long: millis
200101111750
requiredModule Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.logging
name string
java.logging
version string
21.0.7
source Module
classLoader ClassLoader
name string
app
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
10
name string
jdk/internal/loader/ClassLoaders$AppClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
jdk/internal/loader
location string
jrt:/jdk.jshell
name string
jdk.jshell
version string
21.0.7
startTime long: millis
231212350792

ModuleExport

default profiling startTime every chunk 11 17 21 25 26

Category: Java Virtual Machine / Runtime / Modules

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/jfr/periodic/jfrModuleEvent.cpp:

  ModuleExportClosure(const PackageEntry* pkg, EventFunc ef) : ModuleEventCallbackClosure(ef), _package(pkg) {}
  void do_module(ModuleEntry* entry);
};

static void write_module_dependency_event(const void* from_module, const ModuleEntry* to_module) {
  EventModuleRequire event(UNTIMED);
  event.set_endtime(invocation_time);
  event.set_source((const ModuleEntry* const)from_module);
  event.set_requiredModule(to_module);
  event.commit();
}

static void write_module_export_event(const void* package, const ModuleEntry* qualified_export) {
  EventModuleExport event(UNTIMED);
  event.set_endtime(invocation_time);
  event.set_exportedPackage((const PackageEntry*)package);
  event.set_targetModule(qualified_export);
  event.commit();
}

void ModuleDependencyClosure::do_module(ModuleEntry* to_module) {
  assert_locked_or_safepoint(Module_lock);
  assert(to_module != NULL, "invariant");
  assert(_module != NULL, "invariant");
  assert(_event_func != NULL, "invariant");

Configuration enabled period
default true endChunk
profiling true endChunk

Field Type Description
exportedPackage Package Exported Package Consider contributing a description to jfreventcollector.
targetModule Module Target Module Module to which the package is qualifiedly exported. If null or N/A, the package is unqualifiedly exported

Examples 3
exportedPackage Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/net
location string
null
name string
null
version string
null
name string
org/apache/log4j/xml
startTime long: millis
200101199416
targetModule Module
null
exportedPackage Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/net
location string
null
name string
null
version string
null
name string
org/apache/spark/ui/exec
startTime long: millis
243809266625
targetModule Module
null
exportedPackage Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/net
location string
null
name string
null
version string
null
name string
org/apache/hadoop/security
startTime long: millis
231212491500
targetModule Module
null

Java Application

ThreadStart

default profiling startTime eventThread 11 17 21 25 26

Category: Java Application

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/prims/jni.cpp:

#if INCLUDE_JNI_CHECK
  if (CheckJNICalls) return jni_functions_check();
#endif // INCLUDE_JNI_CHECK
  return &jni_NativeInterface;
}

// Returns the function structure
struct JNINativeInterface_* jni_functions_nocheck() {
  return &jni_NativeInterface;
}

static void post_thread_start_event(const JavaThread* jt) {
  assert(jt != NULL, "invariant");
  EventThreadStart event;
  if (event.should_commit()) {
    event.set_thread(JFR_THREAD_ID(jt));
    event.commit();
  }
}

// Invocation API


// Forward declaration
extern const struct JNIInvokeInterface_ jni_InvokeInterface;

src/hotspot/share/jfr/support/jfrThreadLocal.cpp:

void JfrThreadLocal::set_thread_checkpoint(const JfrCheckpointBlobHandle& ref) {
  assert(!_thread_cp.valid(), "invariant");
  _thread_cp = ref;
}

const JfrCheckpointBlobHandle& JfrThreadLocal::thread_checkpoint() const {
  return _thread_cp;
}

static void send_java_thread_start_event(JavaThread* jt) {
  EventThreadStart event;
  event.set_thread(jt->jfr_thread_local()->thread_id());
  event.commit();
}

void JfrThreadLocal::on_start(Thread* t) {
  assert(t != NULL, "invariant");
  assert(Thread::current() == t, "invariant");
  if (JfrRecorder::is_recording()) {
    if (t->is_Java_thread()) {
      send_java_thread_start_event((JavaThread*)t);
    }

Configuration enabled
default true
profiling true

Field Type Description
thread Thread Java Thread

Examples 3
startTime long: millis
237697058167
thread Thread
group ThreadGroup
name string
main
parent ThreadGroup
name string
system
parent ThreadGroup
null
javaName string
block-manager-storage-async-thread-pool-54
javaThreadId long
1662
osName string
block-manager-storage-async-thread-pool-54
osThreadId long
94215
virtual boolean
false
startTime long: millis
222081940208
thread Thread
group ThreadGroup
name string
main
parent ThreadGroup
name string
system
parent ThreadGroup
null
javaName string
block-manager-ask-thread-pool-66
javaThreadId long
1763
osName string
block-manager-ask-thread-pool-66
osThreadId long
247555
virtual boolean
false
startTime long: millis
239200147042
thread Thread
group ThreadGroup
name string
main
parent ThreadGroup
name string
system
parent ThreadGroup
null
javaName string
block-manager-storage-async-thread-pool-73
javaThreadId long
1705
osName string
block-manager-storage-async-thread-pool-73
osThreadId long
72983
virtual boolean
false

ThreadEnd

default profiling startTime eventThread 11 17 21 25 26

Category: Java Application

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/runtime/java.cpp:

  if (HAS_PENDING_EXCEPTION) {
    HandleMark hm(THREAD);
    Handle exception(THREAD, PENDING_EXCEPTION);
    CLEAR_PENDING_EXCEPTION;
    java_lang_Throwable::java_printStackTrace(exception, THREAD);
  }
#endif

  // Hang forever on exit if we're reporting an error.
  if (ShowMessageBoxOnError && VMError::is_error_reported()) {
    os::infinite_sleep();
  }

  EventThreadEnd event;
  if (event.should_commit()) {
    event.set_thread(JFR_THREAD_ID(thread));
    event.commit();
  }

  JFR_ONLY(Jfr::on_vm_shutdown();)

  // Stop the WatcherThread. We do this before disenrolling various
  // PeriodicTasks to reduce the likelihood of races.
  if (PeriodicTask::num_tasks() > 0) {
    WatcherThread::stop();

src/hotspot/share/jfr/support/jfrThreadLocal.cpp:

  assert(t != NULL, "invariant");
  assert(Thread::current() == t, "invariant");
  if (JfrRecorder::is_recording()) {
    if (t->is_Java_thread()) {
      send_java_thread_start_event((JavaThread*)t);
    }
  }
}

static void send_java_thread_end_events(traceid id, JavaThread* jt) {
  assert(jt != NULL, "invariant");
  assert(Thread::current() == jt, "invariant");
  assert(jt->jfr_thread_local()->trace_id() == id, "invariant");
  EventThreadEnd event;
  event.set_thread(id);
  event.commit();
  JfrThreadCPULoadEvent::send_event_for_thread(jt);
}

void JfrThreadLocal::release(JfrThreadLocal* tl, Thread* t) {
  assert(tl != NULL, "invariant");
  assert(t != NULL, "invariant");
  assert(Thread::current() == t, "invariant");
  assert(!tl->is_dead(), "invariant");
  assert(tl->shelved_buffer() == NULL, "invariant");

Configuration enabled
default true
profiling true

Field Type Description
thread Thread Java Thread

Examples 3
startTime long: millis
260803163208
thread Thread
group ThreadGroup
name string
main
parent ThreadGroup
name string
system
parent ThreadGroup
null
javaName string
block-manager-storage-async-thread-pool-62
javaThreadId long
1674
osName string
block-manager-storage-async-thread-pool-62
osThreadId long
137991
virtual boolean
false
startTime long: millis
244810018208
thread Thread
group ThreadGroup
name string
main
parent ThreadGroup
name string
system
parent ThreadGroup
null
javaName string
Executor task launch worker for task 7.0 in stage 20.0 (TID 142)
javaThreadId long
1567
osName string
Executor task launch worker for task 7.0 in stage 20.0 (TID 142)
osThreadId long
85795
virtual boolean
false
startTime long: millis
220016578208
thread Thread
group ThreadGroup
name string
system
parent ThreadGroup
null
javaName string
C2 CompilerThread1
javaThreadId long
15
osName string
C2 CompilerThread1
osThreadId long
86299
virtual boolean
false

ThreadSleep

default profiling startTime duration eventThread stackTrace 11 17 21 25 26

Category: Java Application

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/prims/jvm.cpp:

  // Implied else: If the JavaThread hasn't started yet, then the
  // priority set in the java.lang.Thread object above will be pushed
  // down when it does start.
JVM_END


JVM_ENTRY(void, JVM_Yield(JNIEnv *env, jclass threadClass))
  JVMWrapper("JVM_Yield");
  if (os::dont_yield()) return;
  HOTSPOT_THREAD_YIELD();
  os::naked_yield();
JVM_END

static void post_thread_sleep_event(EventThreadSleep* event, jlong millis) {
  assert(event != NULL, "invariant");
  assert(event->should_commit(), "invariant");
  event->set_time(millis);
  event->commit();
}

JVM_ENTRY(void, JVM_Sleep(JNIEnv* env, jclass threadClass, jlong millis))
  JVMWrapper("JVM_Sleep");

  if (millis < 0) {
    THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), "timeout value is negative");
  }

  if (Thread::is_interrupted (THREAD, true) && !HAS_PENDING_EXCEPTION) {
    THROW_MSG(vmSymbols::java_lang_InterruptedException(), "sleep interrupted");
  }

  // Save current thread state and restore it at the end of this block.
  // And set new thread state to SLEEPING.
  JavaThreadSleepState jtss(thread);

  HOTSPOT_THREAD_SLEEP_BEGIN(millis);
  EventThreadSleep event;

  if (millis == 0) {
    os::naked_yield();
  } else {
    ThreadState old_state = thread->osthread()->get_state();
    thread->osthread()->set_state(SLEEPING);
    if (os::sleep(thread, millis, true) == OS_INTRPT) {
      // An asynchronous exception (e.g., ThreadDeathException) could have been thrown on
      // us while we were sleeping. We do not overwrite those.
      if (!HAS_PENDING_EXCEPTION) {
        if (event.should_commit()) {

Configuration enabled stackTrace threshold
default true true 20 ms
profiling true true 10 ms

Field Type Description
time long: millis Sleep Time

Examples 3
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bootstrap
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java/lang/Thread
package Package
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java.base
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21.0.7
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java/lang
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java/lang/Thread
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java/lang/Thread
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198927245791
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7000000

ThreadPark

default profiling startTime duration eventThread stackTrace 11 17 21 25 26

Category: Java Application

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/prims/unsafe.cpp:

} UNSAFE_END

UNSAFE_ENTRY(jboolean, Unsafe_CompareAndSetLong(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jlong e, jlong x)) {
  oop p = JNIHandles::resolve(obj);
  if (p == NULL) {
    volatile jlong* addr = (volatile jlong*)index_oop_from_field_offset_long(p, offset);
    return RawAccess<>::atomic_cmpxchg(x, addr, e) == e;
  } else {
    assert_field_offset_sane(p, offset);
    return HeapAccess<>::atomic_cmpxchg_at(x, p, (ptrdiff_t)offset, e) == e;
  }
} UNSAFE_END

static void post_thread_park_event(EventThreadPark* event, const oop obj, jlong timeout_nanos, jlong until_epoch_millis) {
  assert(event != NULL, "invariant");
  assert(event->should_commit(), "invariant");
  event->set_parkedClass((obj != NULL) ? obj->klass() : NULL);
  event->set_timeout(timeout_nanos);
  event->set_until(until_epoch_millis);
  event->set_address((obj != NULL) ? (u8)cast_from_oop<uintptr_t>(obj) : 0);
  event->commit();
}

UNSAFE_ENTRY(void, Unsafe_Park(JNIEnv *env, jobject unsafe, jboolean isAbsolute, jlong time)) {
  HOTSPOT_THREAD_PARK_BEGIN((uintptr_t) thread->parker(), (int) isAbsolute, time);
  EventThreadPark event;

  JavaThreadParkedState jtps(thread, time != 0);
  thread->parker()->park(isAbsolute != 0, time);
  if (event.should_commit()) {
    const oop obj = thread->current_park_blocker();
    if (time == 0) {
      post_thread_park_event(&event, obj, min_jlong, min_jlong);
    } else {
      if (isAbsolute != 0) {
        post_thread_park_event(&event, obj, min_jlong, time);
      } else {

Configuration enabled stackTrace threshold
default true true 20 ms
profiling true true 10 ms

Field Type Description
parkedClass Class Class Parked On
timeout long: nanos Park Timeout
until long: epochmillis Park Until
address ulong: address Address of Object Parked

Examples 3
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237793845000
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until long: epochmillis
-9223372036854775808

JavaMonitorEnter

default profiling startTime duration eventThread stackTrace 11 17 21 25 26

Category: Java Application

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/runtime/objectMonitor.cpp:

  assert(_owner != Self, "invariant");
  assert(_succ != Self, "invariant");
  assert(Self->is_Java_thread(), "invariant");
  JavaThread * jt = (JavaThread *) Self;
  assert(!SafepointSynchronize::is_at_safepoint(), "invariant");
  assert(jt->thread_state() != _thread_blocked, "invariant");
  assert(this->object() != NULL, "invariant");
  assert(_count >= 0, "invariant");

  // Prevent deflation at STW-time.  See deflate_idle_monitors() and is_busy().
  // Ensure the object-monitor relationship remains stable while there's contention.
  Atomic::inc(&_count);

  JFR_ONLY(JfrConditionalFlushWithStacktrace<EventJavaMonitorEnter> flush(jt);)
  EventJavaMonitorEnter event;
  if (event.should_commit()) {
    event.set_monitorClass(((oop)this->object())->klass());
    event.set_address((uintptr_t)(this->object_addr()));
  }

  { // Change java thread status to indicate blocked on monitor enter.
    JavaThreadBlockedOnMonitorEnterState jtbmes(jt, this);

    Self->set_current_pending_monitor(this);

    DTRACE_MONITOR_PROBE(contended__enter, this, object(), jt);

src/hotspot/share/runtime/objectMonitor.cpp:

  if (_recursions != 0) {
    _recursions--;        // this is simple recursive enter
    return;
  }

  // Invariant: after setting Responsible=null an thread must execute
  // a MEMBAR or other serializing instruction before fetching EntryList|cxq.
  _Responsible = NULL;

#if INCLUDE_JFR
  // get the owner's thread id for the MonitorEnter event
  // if it is enabled and the thread isn't suspended
  if (not_suspended && EventJavaMonitorEnter::is_enabled()) {
    _previous_owner_tid = JFR_THREAD_ID(Self);
  }
#endif

  for (;;) {
    assert(THREAD == _owner, "invariant");

    // release semantics: prior loads and stores from within the critical section
    // must not float (reorder) past the following store that drops the lock.
    // On SPARC that requires MEMBAR #loadstore|#storestore.
    // But of course in TSO #loadstore|#storestore is not required.

Configuration enabled stackTrace threshold
default true true 20 ms
profiling true true 10 ms

Field Type Description
monitorClass Class Monitor Class Consider contributing a description to jfreventcollector.
previousOwner Thread Previous Monitor Owner
address ulong: address Monitor Address

Examples 3
address ulong: address
105553532649104
monitorClass Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
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modifiers int
1041
name string
[I
package Package
null
previousOwner Thread
group ThreadGroup
name string
main
parent ThreadGroup
name string
system
parent ThreadGroup
null
javaName string
Executor task launch worker-4
javaThreadId long
1871
osName string
Executor task launch worker-4
osThreadId long
44843
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stackTrace StackTrace
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508
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finagle/netty4-2-18
javaThreadId long
2413
osName string
finagle/netty4-2-18
osThreadId long
259399
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false
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(Lcom/twitter/finagle/http/Request;)Lcom/twitter/util/Future;
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Executor task launch worker for task 3.0 in stage 20.0 (TID 138)
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Executor task launch worker for task 3.0 in stage 20.0 (TID 138)
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239464307958

JavaMonitorWait

default profiling startTime duration eventThread stackTrace 11 17 21 25 26

Category: Java Application

Waiting on a Java monitor

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/runtime/objectMonitor.cpp:

        THROW(vmSymbols::java_lang_IllegalMonitorStateException());         \
      }                                                                     \
    }                                                                       \
  } while (false)

// check_slow() is a misnomer.  It's called to simply to throw an IMSX exception.
// TODO-FIXME: remove check_slow() -- it's likely dead.

void ObjectMonitor::check_slow(TRAPS) {
  assert(THREAD != _owner && !THREAD->is_lock_owned((address) _owner), "must not be owner");
  THROW_MSG(vmSymbols::java_lang_IllegalMonitorStateException(), "current thread not owner");
}

static void post_monitor_wait_event(EventJavaMonitorWait* event,
                                    ObjectMonitor* monitor,
                                    jlong notifier_tid,
                                    jlong timeout,
                                    bool timedout) {
  assert(event != NULL, "invariant");
  assert(monitor != NULL, "invariant");
  event->set_monitorClass(((oop)monitor->object())->klass());
  event->set_timeout(timeout);
  event->set_address((uintptr_t)monitor->object_addr());
  event->set_notifier(notifier_tid);
  event->set_timedOut(timedout);

src/hotspot/share/runtime/objectMonitor.cpp:

//
// Note: a subset of changes to ObjectMonitor::wait()
// will need to be replicated in complete_exit
void ObjectMonitor::wait(jlong millis, bool interruptible, TRAPS) {
  Thread * const Self = THREAD;
  assert(Self->is_Java_thread(), "Must be Java thread!");
  JavaThread *jt = (JavaThread *)THREAD;

  assert(InitDone, "Unexpectedly not initialized");

  // Throw IMSX or IEX.
  CHECK_OWNER();

  EventJavaMonitorWait event;

  // check for a pending interrupt
  if (interruptible && Thread::is_interrupted(Self, true) && !HAS_PENDING_EXCEPTION) {
    // post monitor waited event.  Note that this is past-tense, we are done waiting.
    if (JvmtiExport::should_post_monitor_waited()) {
      // Note: 'false' parameter is passed here because the
      // wait was not timed out due to thread interrupt.
      JvmtiExport::post_monitor_waited(jt, this, false);

      // In this short circuit of the monitor wait protocol, the
      // current thread never drops ownership of the monitor and

Configuration enabled stackTrace threshold
default true true 20 ms
profiling true true 10 ms

Field Type Description
monitorClass Class Monitor Class Class of object waited on
notifier Thread Notifier Thread Notifying Thread
timeout long: millis Timeout Maximum wait time
timedOut boolean Timed Out Wait has been timed out
address ulong: address Monitor Address Address of object waited on

Examples 3
address ulong: address
105553600566768
monitorClass Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/lang/Object
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classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
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name string
java/lang
notifier Thread
group ThreadGroup
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main
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null
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Executor task launch worker-1
javaThreadId long
1868
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Executor task launch worker-1
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182791
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274
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java/lang/Object
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java/lang/Object
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java.base
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Executor task launch worker-6
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Executor task launch worker-2
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1
name string
org/apache/spark/sql/catalyst/expressions/objects/Invoke
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/net
location string
null
name string
null
version string
null
name string
org/apache/spark/sql/catalyst/expressions/objects
type FrameType
Interpreted
truncated boolean
false
startTime long: millis
272788703542
timedOut boolean
false
timeout long: millis
0

JavaMonitorInflate

profiling startTime duration eventThread stackTrace 11 17 21 25 26

Category: Java Application

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/runtime/synchronizer.cpp:

    assert(Self->omFreeCount == tally, "free-count off");
    Self->omFreeCount = 0;
  }

  if (inUseTail != NULL) {
    inUseTail->FreeNext = gOmInUseList;
    gOmInUseList = inUseList;
    gOmInUseCount += inUseTally;
  }

  Thread::muxRelease(&gListLock);
}

static void post_monitor_inflate_event(EventJavaMonitorInflate* event,
                                       const oop obj,
                                       ObjectSynchronizer::InflateCause cause) {
  assert(event != NULL, "invariant");
  assert(event->should_commit(), "invariant");
  event->set_monitorClass(obj->klass());
  event->set_address((uintptr_t)(void*)obj);
  event->set_cause((u1)cause);
  event->commit();
}

// Fast path code shared by multiple functions

src/hotspot/share/runtime/synchronizer.cpp:

                                     obj,
                                     inflate_cause_vm_internal);
}

ObjectMonitor* ObjectSynchronizer::inflate(Thread * Self,
                                                     oop object,
                                                     const InflateCause cause) {

  // Inflate mutates the heap ...
  // Relaxing assertion for bug 6320749.
  assert(Universe::verify_in_progress() ||
         !SafepointSynchronize::is_at_safepoint(), "invariant");

  EventJavaMonitorInflate event;

  for (;;) {
    const markOop mark = object->mark();
    assert(!mark->has_bias_pattern(), "invariant");

    // The mark can be in one of the following states:
    // *  Inflated     - just return
    // *  Stack-locked - coerce it to inflated
    // *  INFLATING    - busy wait for conversion to complete
    // *  Neutral      - aggressively inflate the object.
    // *  BIASED       - Illegal.  We should never see this

Configuration enabled stackTrace threshold
default false true 20 ms
profiling true true 10 ms

Field Type Description
monitorClass Class Monitor Class Consider contributing a description to jfreventcollector.
address ulong: address Monitor Address
cause InflateCause Monitor Inflation Cause Cause of inflation

ObjectAllocationInNewTLAB

profiling startTime eventThread stackTrace 11 17 21 25 26

Category: Java Application

Allocation in new Thread Local Allocation Buffer

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/gc/shared/allocTracer.cpp:

void AllocTracer::send_allocation_outside_tlab(Klass* klass, HeapWord* obj, size_t alloc_size, Thread* thread) {
  JFR_ONLY(JfrAllocationTracer tracer(obj, alloc_size, thread);)
  EventObjectAllocationOutsideTLAB event;
  if (event.should_commit()) {
    event.set_objectClass(klass);
    event.set_allocationSize(alloc_size);
    event.commit();
  }
}

void AllocTracer::send_allocation_in_new_tlab(Klass* klass, HeapWord* obj, size_t tlab_size, size_t alloc_size, Thread* thread) {
  JFR_ONLY(JfrAllocationTracer tracer(obj, alloc_size, thread);)
  EventObjectAllocationInNewTLAB event;
  if (event.should_commit()) {
    event.set_objectClass(klass);
    event.set_allocationSize(alloc_size);
    event.set_tlabSize(tlab_size);
    event.commit();
  }
}

void AllocTracer::send_allocation_requiring_gc_event(size_t size, uint gcId) {
  EventAllocationRequiringGC event;
  if (event.should_commit()) {

Configuration enabled stackTrace
default false true
profiling true true

Field Type Description
objectClass Class Object Class Class of allocated object
allocationSize ulong: bytes Allocation Size
tlabSize ulong: bytes TLAB Size

Examples 3
allocationSize ulong: bytes
32
objectClass Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
24
name string
java/util/concurrent/locks/AbstractQueuedSynchronizer$ConditionNode
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/util/concurrent/locks
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
10
lineNumber int
1627
method Method
descriptor string
()Ljava/util/concurrent/locks/AbstractQueuedSynchronizer$ConditionNode;
hidden boolean
false
modifiers int
2
name string
newConditionNode
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/util/concurrent/locks/AbstractQueuedSynchronizer$ConditionObject
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/util/concurrent/locks
type FrameType
Inlined
truncated boolean
false
startTime long: millis
237699784417
tlabSize ulong: bytes
126568
allocationSize ulong: bytes
40
objectClass Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
24
name string
java/util/TreeMap$Entry
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/util
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
8
lineNumber int
812
method Method
descriptor string
(Ljava/lang/Object;Ljava/lang/Object;)V
hidden boolean
false
modifiers int
2
name string
addEntryToEmptyMap
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/util/TreeMap
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/util
type FrameType
JIT compiled
truncated boolean
false
startTime long: millis
229754724708
tlabSize ulong: bytes
3112
allocationSize ulong: bytes
48
objectClass Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/util/HashMap
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/util
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
34
lineNumber int
89
method Method
descriptor string
(Ljava/lang/String;Ljava/lang/String;)V
hidden boolean
false
modifiers int
1
name string
put
type Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/net
hidden boolean
false
modifiers int
1
name string
org/apache/logging/log4j/spi/DefaultThreadContextMap
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/net
location string
null
name string
null
version string
null
name string
org/apache/logging/log4j/spi
type FrameType
Interpreted
truncated boolean
false
startTime long: millis
199168054583
tlabSize ulong: bytes
4194304

ObjectAllocationOutsideTLAB

profiling startTime eventThread stackTrace 11 17 21 25 26

Category: Java Application

Allocation outside Thread Local Allocation Buffers

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/gc/shared/allocTracer.cpp:

#if INCLUDE_JFR
#include "jfr/support/jfrAllocationTracer.hpp"
#endif

void AllocTracer::send_allocation_outside_tlab(Klass* klass, HeapWord* obj, size_t alloc_size, Thread* thread) {
  JFR_ONLY(JfrAllocationTracer tracer(obj, alloc_size, thread);)
  EventObjectAllocationOutsideTLAB event;
  if (event.should_commit()) {
    event.set_objectClass(klass);
    event.set_allocationSize(alloc_size);
    event.commit();
  }
}

void AllocTracer::send_allocation_in_new_tlab(Klass* klass, HeapWord* obj, size_t tlab_size, size_t alloc_size, Thread* thread) {
  JFR_ONLY(JfrAllocationTracer tracer(obj, alloc_size, thread);)
  EventObjectAllocationInNewTLAB event;
  if (event.should_commit()) {

Configuration enabled stackTrace
default false true
profiling true true

Field Type Description
objectClass Class Object Class Class of allocated object
allocationSize ulong: bytes Allocation Size

Examples 3
allocationSize ulong: bytes
65552
objectClass Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1040
name string
[Ljava/util/HashMap$Node;
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/util
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
133
lineNumber int
710
method Method
descriptor string
()[Ljava/util/HashMap$Node;
hidden boolean
false
modifiers int
16
name string
resize
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/util/HashMap
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/util
type FrameType
JIT compiled
truncated boolean
false
startTime long: millis
245135160250
allocationSize ulong: bytes
32952
objectClass Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1041
name string
[B
package Package
null
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
50
lineNumber int
104
method Method
descriptor string
(Ljava/io/OutputStream;ILnet/jpountz/lz4/LZ4Compressor;Ljava/util/zip/Checksum;Z)V
hidden boolean
false
modifiers int
1
name string
<init>
type Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/net
hidden boolean
false
modifiers int
1
name string
net/jpountz/lz4/LZ4BlockOutputStream
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/net
location string
null
name string
null
version string
null
name string
net/jpountz/lz4
type FrameType
JIT compiled
truncated boolean
false
startTime long: millis
237761223542
allocationSize ulong: bytes
32784
objectClass Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1041
name string
[B
package Package
null
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
31
lineNumber int
102
method Method
descriptor string
(Ljava/io/OutputStream;ILnet/jpountz/lz4/LZ4Compressor;Ljava/util/zip/Checksum;Z)V
hidden boolean
false
modifiers int
1
name string
<init>
type Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/net
hidden boolean
false
modifiers int
1
name string
net/jpountz/lz4/LZ4BlockOutputStream
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/net
location string
null
name string
null
version string
null
name string
net/jpountz/lz4
type FrameType
JIT compiled
truncated boolean
false
startTime long: millis
200881987125

JavaErrorThrow

default profiling startTime duration stackTrace 11 17 21 25 26

Source src/jdk.jfr/share/classes/jdk/jfr/events/ErrorThrownEvent.java

Category: Java Application

An object derived from java.lang.Error has been created. OutOfMemoryErrors are ignored

Configuration enabled stackTrace
default true true
profiling true true

Field Type Description
message string Message Consider contributing a description to jfreventcollector.
thrownClass Class Class Consider contributing a description to jfreventcollector.

Examples 3
message string
static Lorg/apache/spark/executor/ShuffleWriteMetrics;.<clinit>()V
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
7
lineNumber int
68
method Method
descriptor string
(Ljava/lang/String;)V
hidden boolean
false
modifiers int
1
name string
<init>
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/lang/Error
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/lang
type FrameType
Inlined
truncated boolean
false
startTime long: millis
253207658708
thrownClass Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/lang/NoSuchMethodError
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/lang
message string
static Lorg/apache/spark/sql/catalyst/expressions/BoundReference;.<clinit>()V
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
7
lineNumber int
68
method Method
descriptor string
(Ljava/lang/String;)V
hidden boolean
false
modifiers int
1
name string
<init>
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/lang/Error
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/lang
type FrameType
Inlined
truncated boolean
true
startTime long: millis
273971180000
thrownClass Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/lang/NoSuchMethodError
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/lang
message string
static Lorg/apache/spark/sql/execution/metric/SQLMetric;.<clinit>()V
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
7
lineNumber int
68
method Method
descriptor string
(Ljava/lang/String;)V
hidden boolean
false
modifiers int
1
name string
<init>
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/lang/Error
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
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21.0.7
name string
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type FrameType
Inlined
truncated boolean
true
startTime long: millis
233051729250
thrownClass Class
classLoader ClassLoader
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bootstrap
type Class
null
hidden boolean
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modifiers int
1
name string
java/lang/NoSuchMethodError
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/lang

FileForce

default profiling startTime duration stackTrace 11 17 21 25 26

Source src/jdk.jfr/share/classes/jdk/jfr/events/FileForceEvent.java

Category: Java Application

Force updates to be written to file

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/jdk.jfr/share/classes/jdk/jfr/events/FileForceEvent.java:

package jdk.jfr.events;

import jdk.jfr.Category;
import jdk.jfr.Description;
import jdk.jfr.Label;
import jdk.jfr.Name;
import jdk.jfr.internal.Type;

@Name(Type.EVENT_NAME_PREFIX + "FileForce")
@Label("File Force")
@Category("Java Application")
@Description("Force updates to be written to file")
public final class FileForceEvent extends AbstractJDKEvent {

    public static final ThreadLocal<FileForceEvent> EVENT =
        new ThreadLocal<>() {
            @Override protected FileForceEvent initialValue() {
                return new FileForceEvent();
            }
        };

    @Label("Path")
    @Description("Full path of the file")
    public String path;

    @Label("Update Metadata")
    @Description("Whether the file metadata is updated")
    public boolean metaData;

src/jdk.jfr/share/classes/jdk/jfr/internal/instrument/JDKEvents.java:

public final class JDKEvents {

    private static final Class<?>[] mirrorEventClasses = {
        SecurityPropertyModificationEvent.class,
        TLSHandshakeEvent.class,
        X509CertificateEvent.class,
        X509ValidationEvent.class
    };

    private static final Class<?>[] eventClasses = {
        FileForceEvent.class,
        FileReadEvent.class,
        FileWriteEvent.class,
        SocketReadEvent.class,
        SocketWriteEvent.class,
        ExceptionThrownEvent.class,
        ExceptionStatisticsEvent.class,
        ErrorThrownEvent.class,
        ActiveSettingEvent.class,
        ActiveRecordingEvent.class,
        jdk.internal.event.SecurityPropertyModificationEvent.class,
        jdk.internal.event.TLSHandshakeEvent.class,

src/jdk.jfr/share/classes/jdk/jfr/internal/instrument/FileChannelImplInstrumentor.java:

 * See {@link JITracer} for an explanation of this code.
 */
@JIInstrumentationTarget("sun.nio.ch.FileChannelImpl")
final class FileChannelImplInstrumentor {

    private FileChannelImplInstrumentor() {
    }

    private String path;

    @SuppressWarnings("deprecation")
    @JIInstrumentationMethod
    public void force(boolean metaData) throws IOException {
        FileForceEvent event = FileForceEvent.EVENT.get();
        if (!event.isEnabled()) {
            force(metaData);
            return;
        }
        try {
            event.begin();
            force(metaData);
        } finally {
            event.path = path;
            event.metaData = metaData;
            event.commit();

Configuration enabled stackTrace threshold
default true true 20 ms
profiling true true 10 ms

Field Type Description
path string Path Full path of the file
metaData boolean Update Metadata Whether the file metadata is updated

SocketWrite

default profiling startTime duration stackTrace 11 17 21 25 26

Source src/jdk.jfr/share/classes/jdk/jfr/events/SocketWriteEvent.java

Category: Java Application

Writing data to a socket

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/jdk.jfr/share/classes/jdk/jfr/events/SocketWriteEvent.java:

package jdk.jfr.events;

import jdk.jfr.Category;
import jdk.jfr.Description;
import jdk.jfr.Label;
import jdk.jfr.DataAmount;
import jdk.jfr.Name;
import jdk.jfr.internal.Type;

@Name(Type.EVENT_NAME_PREFIX + "SocketWrite")
@Label("Socket Write")
@Category("Java Application")
@Description("Writing data to a socket")
public final class SocketWriteEvent extends AbstractJDKEvent {

    public static final ThreadLocal<SocketWriteEvent> EVENT =
        new ThreadLocal<>() {
            @Override protected SocketWriteEvent initialValue() {
                return new SocketWriteEvent();
            }
        };

    @Label("Remote Host")
    public String host;

    @Label("Remote Address")
    public String address;

    @Label("Remote Port")
    public int port;

src/jdk.jfr/share/classes/jdk/jfr/internal/instrument/JDKEvents.java:

    private static final Class<?>[] mirrorEventClasses = {
        SecurityPropertyModificationEvent.class,
        TLSHandshakeEvent.class,
        X509CertificateEvent.class,
        X509ValidationEvent.class
    };

    private static final Class<?>[] eventClasses = {
        FileForceEvent.class,
        FileReadEvent.class,
        FileWriteEvent.class,
        SocketReadEvent.class,
        SocketWriteEvent.class,
        ExceptionThrownEvent.class,
        ExceptionStatisticsEvent.class,
        ErrorThrownEvent.class,
        ActiveSettingEvent.class,
        ActiveRecordingEvent.class,
        jdk.internal.event.SecurityPropertyModificationEvent.class,
        jdk.internal.event.TLSHandshakeEvent.class,
        jdk.internal.event.X509CertificateEvent.class,
        jdk.internal.event.X509ValidationEvent.class
    };

src/jdk.jfr/share/classes/jdk/jfr/internal/instrument/SocketChannelImplInstrumentor.java:

                event.timeout   = 0;

                event.commit();
                event.reset();
            }
        }
        return bytesRead;
    }

    @SuppressWarnings("deprecation")
    @JIInstrumentationMethod
    public int write(ByteBuffer buf) throws IOException {
        SocketWriteEvent event = SocketWriteEvent.EVENT.get();
        if (!event.isEnabled()) {
            return write(buf);
        }

        int bytesWritten = 0;
        try {
            event.begin();
            bytesWritten = write(buf);
        } finally {
            event.end();
            if (event.shouldCommit()) {

src/jdk.jfr/share/classes/jdk/jfr/internal/instrument/SocketChannelImplInstrumentor.java:

                event.port         = remoteAddress.getPort();
                event.bytesWritten = bytesWritten < 0 ? 0 : bytesWritten;

                event.commit();
                event.reset();
            }
        }
        return bytesWritten;
    }

    @SuppressWarnings("deprecation")
    @JIInstrumentationMethod
    public long write(ByteBuffer[] srcs, int offset, int length) throws IOException {
        SocketWriteEvent event = SocketWriteEvent.EVENT.get();
        if (!event.isEnabled()) {
            return write(srcs, offset, length);
        }
        long bytesWritten = 0;
        try {
            event.begin();
            bytesWritten = write(srcs, offset, length);
        } finally {
            event.end();
            if (event.shouldCommit()) {
                String hostString  = remoteAddress.getAddress().toString();

src/jdk.jfr/share/classes/jdk/jfr/internal/instrument/SocketOutputStreamInstrumentor.java:

 * See {@link JITracer} for an explanation of this code.
 */
@JIInstrumentationTarget("java.net.SocketOutputStream")
@JITypeMapping(from = "jdk.jfr.internal.instrument.SocketOutputStreamInstrumentor$AbstractPlainSocketImpl",
            to = "java.net.AbstractPlainSocketImpl")
final class SocketOutputStreamInstrumentor {

    private SocketOutputStreamInstrumentor() {
    }

    @SuppressWarnings("deprecation")
    @JIInstrumentationMethod
    private void socketWrite(byte b[], int off, int len) throws IOException {
        SocketWriteEvent event = SocketWriteEvent.EVENT.get();
        if (!event.isEnabled()) {
            socketWrite(b, off, len);
            return;
        }
        int bytesWritten = 0;
        try {
            event.begin();
            socketWrite(b, off, len);
            bytesWritten = len;
        } finally {
            event.end() ;

Configuration enabled stackTrace threshold
default true true 20 ms
profiling true true 10 ms

Field Type Description
host string Remote Host
address string Remote Address
port int Remote Port
bytesWritten long: bytes Bytes Written Number of bytes written to the socket

Examples 3
address string
127.0.0.1
bytesWritten long: bytes
91
host string
localhost
port int
53378
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
584
lineNumber int
191
method Method
descriptor string
([Ljava/nio/ByteBuffer;II)J
hidden boolean
false
modifiers int
1
name string
write
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
0
name string
sun/nio/ch/SocketChannelImpl
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
sun/nio/ch
type FrameType
JIT compiled
truncated boolean
false
startTime long: millis
253171569541
address string
127.0.0.1
bytesWritten long: bytes
32
host string
port int
55732
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
584
lineNumber int
191
method Method
descriptor string
([Ljava/nio/ByteBuffer;II)J
hidden boolean
false
modifiers int
1
name string
write
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
0
name string
sun/nio/ch/SocketChannelImpl
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
sun/nio/ch
type FrameType
JIT compiled
truncated boolean
false
startTime long: millis
292518303625
address string
127.0.0.1
bytesWritten long: bytes
101
host string
localhost
port int
54137
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
584
lineNumber int
191
method Method
descriptor string
([Ljava/nio/ByteBuffer;II)J
hidden boolean
false
modifiers int
1
name string
write
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
0
name string
sun/nio/ch/SocketChannelImpl
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
sun/nio/ch
type FrameType
JIT compiled
truncated boolean
true
startTime long: millis
269273325375

JavaExceptionThrow

startTime duration stackTrace 11 17 21 25 26

Source src/jdk.jfr/share/classes/jdk/jfr/events/ExceptionThrownEvent.java

Category: Java Application

An object derived from java.lang.Exception has been created

Configuration enabled stackTrace
default false true
profiling false true

Field Type Description
message string Message Consider contributing a description to jfreventcollector.
thrownClass Class Class Consider contributing a description to jfreventcollector.

Examples 3
message string
null
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
62
lineNumber int
375
method Method
descriptor string
(Ljava/lang/String;Ljava/lang/Throwable;ZZ)V
hidden boolean
false
modifiers int
4
name string
<init>
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/lang/Throwable
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/lang
type FrameType
JIT compiled
truncated boolean
false
startTime long: millis
230287686125
thrownClass Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/net
hidden boolean
false
modifiers int
1
name string
scala/runtime/NonLocalReturnControl
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/net
location string
null
name string
null
version string
null
name string
scala/runtime
message string
null
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
30
lineNumber int
259
method Method
descriptor string
()V
hidden boolean
false
modifiers int
1
name string
<init>
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/lang/Throwable
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/lang
type FrameType
JIT compiled
truncated boolean
true
startTime long: millis
237739133458
thrownClass Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/io/EOFException
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/io
message string
null
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
62
lineNumber int
375
method Method
descriptor string
(Ljava/lang/String;Ljava/lang/Throwable;ZZ)V
hidden boolean
false
modifiers int
4
name string
<init>
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/lang/Throwable
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/lang
type FrameType
JIT compiled
truncated boolean
false
startTime long: millis
198990064916
thrownClass Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/net
hidden boolean
false
modifiers int
1
name string
scala/runtime/NonLocalReturnControl
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/net
location string
null
name string
null
version string
null
name string
scala/runtime

FileWrite

default profiling startTime duration stackTrace 11 17 21 25 26

Source src/jdk.jfr/share/classes/jdk/jfr/events/FileWriteEvent.java

Category: Java Application

Appearing in: G1GC

Missing in: ParallelGC, SerialGC, ShenandoahGC, ZGC

Writing data to a file

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/jdk.jfr/share/classes/jdk/jfr/events/FileWriteEvent.java:

package jdk.jfr.events;

import jdk.jfr.Category;
import jdk.jfr.Description;
import jdk.jfr.Label;
import jdk.jfr.DataAmount;
import jdk.jfr.Name;
import jdk.jfr.internal.Type;

@Name(Type.EVENT_NAME_PREFIX + "FileWrite")
@Label("File Write")
@Category("Java Application")
@Description("Writing data to a file")
public final class FileWriteEvent extends AbstractJDKEvent {

    public static final ThreadLocal<FileWriteEvent> EVENT =
        new ThreadLocal<>() {
            @Override protected FileWriteEvent initialValue() {
                return new FileWriteEvent();
            }
        };

    @Label("Path")
    @Description("Full path of the file")
    public String path;

    @Label("Bytes Written")
    @Description("Number of bytes written to the file")
    @DataAmount
    public long bytesWritten;

src/jdk.jfr/share/classes/jdk/jfr/internal/instrument/JDKEvents.java:

public final class JDKEvents {

    private static final Class<?>[] mirrorEventClasses = {
        SecurityPropertyModificationEvent.class,
        TLSHandshakeEvent.class,
        X509CertificateEvent.class,
        X509ValidationEvent.class
    };

    private static final Class<?>[] eventClasses = {
        FileForceEvent.class,
        FileReadEvent.class,
        FileWriteEvent.class,
        SocketReadEvent.class,
        SocketWriteEvent.class,
        ExceptionThrownEvent.class,
        ExceptionStatisticsEvent.class,
        ErrorThrownEvent.class,
        ActiveSettingEvent.class,
        ActiveRecordingEvent.class,
        jdk.internal.event.SecurityPropertyModificationEvent.class,
        jdk.internal.event.TLSHandshakeEvent.class,
        jdk.internal.event.X509CertificateEvent.class,
        jdk.internal.event.X509ValidationEvent.class

src/jdk.jfr/share/classes/jdk/jfr/internal/instrument/RandomAccessFileInstrumentor.java:

            } else {
                event.bytesRead = bytesRead;
            }
            event.path = path;
            event.commit();
            event.reset();
        }
        return bytesRead;
    }

    @SuppressWarnings("deprecation")
    @JIInstrumentationMethod
    public void write(int b) throws IOException {
        FileWriteEvent event = FileWriteEvent.EVENT.get();
        if (!event.isEnabled()) {
            write(b);
            return;
        }
        try {
            event.begin();
            write(b);
            event.bytesWritten = 1;
        } finally {
            event.path = path;
            event.commit();
            event.reset();
        }
    }

    @SuppressWarnings("deprecation")
    @JIInstrumentationMethod
    public void write(byte b[]) throws IOException {
        FileWriteEvent event = FileWriteEvent.EVENT.get();
        if (!event.isEnabled()) {
            write(b);
            return;
        }
        try {
            event.begin();
            write(b);
            event.bytesWritten = b.length;
        } finally {
            event.path = path;
            event.commit();
            event.reset();
        }
    }

    @SuppressWarnings("deprecation")
    @JIInstrumentationMethod
    public void write(byte b[], int off, int len) throws IOException {
        FileWriteEvent event = FileWriteEvent.EVENT.get();
        if (!event.isEnabled()) {
            write(b, off, len);
            return;
        }
        try {
            event.begin();
            write(b, off, len);
            event.bytesWritten = len;
        } finally {
            event.path = path;
            event.commit();

src/jdk.jfr/share/classes/jdk/jfr/internal/instrument/FileChannelImplInstrumentor.java:

            } else {
                event.bytesRead = bytesRead;
            }
            event.path = path;
            event.commit();
            event.reset();
        }
        return bytesRead;
    }

    @SuppressWarnings("deprecation")
    @JIInstrumentationMethod
    public int write(ByteBuffer src) throws IOException {
        FileWriteEvent event = FileWriteEvent.EVENT.get();
        if (!event.isEnabled()) {
            return write(src);
        }
        int bytesWritten = 0;
        try {
            event.begin();
            bytesWritten = write(src);
        } finally {
            event.bytesWritten = bytesWritten > 0 ? bytesWritten : 0;
            event.path = path;
            event.commit();
            event.reset();
        }
        return bytesWritten;
    }

    @SuppressWarnings("deprecation")
    @JIInstrumentationMethod
    public int write(ByteBuffer src, long position) throws IOException {
        FileWriteEvent event = FileWriteEvent.EVENT.get();
        if (!event.isEnabled()) {
            return write(src, position);
        }

        int bytesWritten = 0;
        try {
            event.begin();
            bytesWritten = write(src, position);
        } finally {
            event.bytesWritten = bytesWritten > 0 ? bytesWritten : 0;
            event.path = path;
            event.commit();
            event.reset();
        }
        return bytesWritten;
    }

    @SuppressWarnings("deprecation")
    @JIInstrumentationMethod
    public long write(ByteBuffer[] srcs, int offset, int length) throws IOException {
        FileWriteEvent event = FileWriteEvent.EVENT.get();
        if (!event.isEnabled()) {
            return write(srcs, offset, length);
        }
        long bytesWritten = 0;
        try {
            event.begin();
            bytesWritten = write(srcs, offset, length);
        } finally {
            event.bytesWritten = bytesWritten > 0 ? bytesWritten : 0;
            event.path = path;
            event.commit();

src/jdk.jfr/share/classes/jdk/jfr/internal/instrument/FileOutputStreamInstrumentor.java:

 * See {@link JITracer} for an explanation of this code.
 */
@JIInstrumentationTarget("java.io.FileOutputStream")
final class FileOutputStreamInstrumentor {

    private FileOutputStreamInstrumentor() {
    }

    private String path;

    @SuppressWarnings("deprecation")
    @JIInstrumentationMethod
    public void write(int b) throws IOException {
        FileWriteEvent event = FileWriteEvent.EVENT.get();
        if (!event.isEnabled()) {
            write(b);
            return;
        }
        try {
            event.begin();
            write(b);
            event.bytesWritten = 1;
        } finally {
            event.path = path;
            event.commit();
            event.reset();
        }
    }

    @SuppressWarnings("deprecation")
    @JIInstrumentationMethod
    public void write(byte b[]) throws IOException {
        FileWriteEvent event = FileWriteEvent.EVENT.get();
        if (!event.isEnabled()) {
            write(b);
            return;
        }
        try {
            event.begin();
            write(b);
            event.bytesWritten = b.length;
        } finally {
            event.path = path;
            event.commit();
            event.reset();
        }
    }

    @SuppressWarnings("deprecation")
    @JIInstrumentationMethod
    public void write(byte b[], int off, int len) throws IOException {
        FileWriteEvent event = FileWriteEvent.EVENT.get();
        if (!event.isEnabled()) {
            write(b, off, len);
            return;
        }
        try {
            event.begin();
            write(b, off, len);
            event.bytesWritten = len;
        } finally {
            event.path = path;
            event.commit();

Configuration enabled stackTrace threshold
default true true 20 ms
profiling true true 10 ms

Field Type Description
path string Path Full path of the file
bytesWritten long: bytes Bytes Written Number of bytes written to the file

Examples 1
bytesWritten long: bytes
4356
path string
[...]_1/code/experiments/jfreventcollector/harness-130453-1906420335947283803/apache-spark/log-regression/blockmgr-bce61232-add2-496c-aa06-56d21451dcb8/11/shuffle_2_38_0.data.bf2e661e-20b8-4658-a95e-6c134ddf2977
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
171
lineNumber int
103
method Method
descriptor string
([BII)V
hidden boolean
false
modifiers int
1
name string
write
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/io/FileOutputStream
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/io
type FrameType
Interpreted
truncated boolean
false
startTime long: millis
235557301625

SocketRead

default profiling startTime duration stackTrace 11 17 21 25 26

Source src/jdk.jfr/share/classes/jdk/jfr/events/SocketReadEvent.java

Category: Java Application

Appearing in: G1GC, ParallelGC, SerialGC, ZGC

Missing in: ShenandoahGC

Reading data from a socket

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/jdk.jfr/share/classes/jdk/jfr/events/SocketReadEvent.java:

@Name(Type.EVENT_NAME_PREFIX + "SocketRead")
@Label("Socket Read")
@Category("Java Application")
@Description("Reading data from a socket")
public final class SocketReadEvent extends AbstractJDKEvent {

    public static final ThreadLocal<SocketReadEvent> EVENT =
        new ThreadLocal<>() {
            @Override protected SocketReadEvent initialValue() {
                return new SocketReadEvent();
            }
        };

    @Label("Remote Host")
    public String host;

    @Label("Remote Address")
    public String address;

    @Label("Remote Port")
    public int port;

src/jdk.jfr/share/classes/jdk/jfr/internal/instrument/JDKEvents.java:

public final class JDKEvents {

    private static final Class<?>[] mirrorEventClasses = {
        SecurityPropertyModificationEvent.class,
        TLSHandshakeEvent.class,
        X509CertificateEvent.class,
        X509ValidationEvent.class
    };

    private static final Class<?>[] eventClasses = {
        FileForceEvent.class,
        FileReadEvent.class,
        FileWriteEvent.class,
        SocketReadEvent.class,
        SocketWriteEvent.class,
        ExceptionThrownEvent.class,
        ExceptionStatisticsEvent.class,
        ErrorThrownEvent.class,
        ActiveSettingEvent.class,
        ActiveRecordingEvent.class,
        jdk.internal.event.SecurityPropertyModificationEvent.class,
        jdk.internal.event.TLSHandshakeEvent.class,
        jdk.internal.event.X509CertificateEvent.class,
        jdk.internal.event.X509ValidationEvent.class
    };

src/jdk.jfr/share/classes/jdk/jfr/internal/instrument/SocketChannelImplInstrumentor.java:

 * See {@link JITracer} for an explanation of this code.
 */
@JIInstrumentationTarget("sun.nio.ch.SocketChannelImpl")
final class SocketChannelImplInstrumentor {

    private SocketChannelImplInstrumentor() {
    }

    private InetSocketAddress remoteAddress;

    @SuppressWarnings("deprecation")
    @JIInstrumentationMethod
    public int read(ByteBuffer dst) throws IOException {
        SocketReadEvent event = SocketReadEvent.EVENT.get();
        if (!event.isEnabled()) {
            return read(dst);
        }
        int bytesRead = 0;
        try {
            event.begin();
            bytesRead = read(dst);
        } finally {
            event.end();
            if (event.shouldCommit())  {
                String hostString  = remoteAddress.getAddress().toString();

src/jdk.jfr/share/classes/jdk/jfr/internal/instrument/SocketChannelImplInstrumentor.java:

                event.timeout   = 0;

                event.commit();
                event.reset();
            }
        }
        return bytesRead;
    }

    @SuppressWarnings("deprecation")
    @JIInstrumentationMethod
    public long read(ByteBuffer[] dsts, int offset, int length) throws IOException {
        SocketReadEvent event = SocketReadEvent.EVENT.get();
        if(!event.isEnabled()) {
            return read(dsts, offset, length);
        }

        long bytesRead = 0;
        try {
            event.begin();
            bytesRead = read(dsts, offset, length);
        } finally {
            event.end();
            if (event.shouldCommit()) {

src/jdk.jfr/share/classes/jdk/jfr/internal/instrument/SocketInputStreamInstrumentor.java:

 * See {@link JITracer} for an explanation of this code.
 */
@JIInstrumentationTarget("java.net.SocketInputStream")
@JITypeMapping(from = "jdk.jfr.internal.instrument.SocketInputStreamInstrumentor$AbstractPlainSocketImpl",
            to = "java.net.AbstractPlainSocketImpl")
final class SocketInputStreamInstrumentor {

    private SocketInputStreamInstrumentor() {
    }

    @SuppressWarnings("deprecation")
    @JIInstrumentationMethod
    int read(byte b[], int off, int length, int timeout) throws IOException {
        SocketReadEvent event = SocketReadEvent.EVENT.get();
        if (!event.isEnabled()) {
            return read(b, off, length, timeout);
        }
        int bytesRead = 0;
        try {
            event.begin();
            bytesRead = read(b, off, length, timeout);
        } finally {
            event.end();
            if (event.shouldCommit()) {
                String hostString  = impl.address.toString();

Configuration enabled stackTrace threshold
default true true 20 ms
profiling true true 10 ms

Field Type Description
host string Remote Host
address string Remote Address
port int Remote Port
timeout long: millis Timeout Value
bytesRead long: bytes Bytes Read Number of bytes read from the socket
endOfStream boolean End of Stream If end of stream was reached

Examples 3
address string
127.0.0.1
bytesRead long: bytes
60
endOfStream boolean
false
host string
localhost
port int
55171
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
846
lineNumber int
72
method Method
descriptor string
(Ljava/nio/ByteBuffer;)I
hidden boolean
false
modifiers int
1
name string
read
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
0
name string
sun/nio/ch/SocketChannelImpl
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
sun/nio/ch
type FrameType
JIT compiled
truncated boolean
false
startTime long: millis
292147302375
timeout long: millis
0
address string
127.0.0.1
bytesRead long: bytes
10
endOfStream boolean
false
host string
localhost
port int
54137
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
846
lineNumber int
72
method Method
descriptor string
(Ljava/nio/ByteBuffer;)I
hidden boolean
false
modifiers int
1
name string
read
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
0
name string
sun/nio/ch/SocketChannelImpl
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
sun/nio/ch
type FrameType
JIT compiled
truncated boolean
false
startTime long: millis
269273625250
timeout long: millis
0
address string
127.0.0.1
bytesRead long: bytes
13
endOfStream boolean
false
host string
port int
54014
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
846
lineNumber int
72
method Method
descriptor string
(Ljava/nio/ByteBuffer;)I
hidden boolean
false
modifiers int
1
name string
read
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
0
name string
sun/nio/ch/SocketChannelImpl
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
sun/nio/ch
type FrameType
JIT compiled
truncated boolean
false
startTime long: millis
251773180208
timeout long: millis
0

FileRead

default profiling startTime duration stackTrace 11 17 21 25 26

Source src/jdk.jfr/share/classes/jdk/jfr/events/FileReadEvent.java

Category: Java Application

Appearing in: G1GC, SerialGC

Missing in: ParallelGC, ShenandoahGC, ZGC

Reading data from a file

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/jdk.jfr/share/classes/jdk/jfr/events/FileReadEvent.java:

package jdk.jfr.events;

import jdk.jfr.Category;
import jdk.jfr.Description;
import jdk.jfr.Label;
import jdk.jfr.DataAmount;
import jdk.jfr.Name;
import jdk.jfr.internal.Type;

@Name(Type.EVENT_NAME_PREFIX + "FileRead")
@Label("File Read")
@Category("Java Application")
@Description("Reading data from a file")
public final class FileReadEvent extends AbstractJDKEvent {

    public static final ThreadLocal<FileReadEvent> EVENT =
        new ThreadLocal<>() {
            @Override protected FileReadEvent initialValue() {
                return new FileReadEvent();
            }
        };

    @Label("Path")
    @Description("Full path of the file")
    public String path;

    @Label("Bytes Read")
    @Description("Number of bytes read from the file (possibly 0)")
    @DataAmount
    public long bytesRead;

src/jdk.jfr/share/classes/jdk/jfr/internal/instrument/JDKEvents.java:

public final class JDKEvents {

    private static final Class<?>[] mirrorEventClasses = {
        SecurityPropertyModificationEvent.class,
        TLSHandshakeEvent.class,
        X509CertificateEvent.class,
        X509ValidationEvent.class
    };

    private static final Class<?>[] eventClasses = {
        FileForceEvent.class,
        FileReadEvent.class,
        FileWriteEvent.class,
        SocketReadEvent.class,
        SocketWriteEvent.class,
        ExceptionThrownEvent.class,
        ExceptionStatisticsEvent.class,
        ErrorThrownEvent.class,
        ActiveSettingEvent.class,
        ActiveRecordingEvent.class,
        jdk.internal.event.SecurityPropertyModificationEvent.class,
        jdk.internal.event.TLSHandshakeEvent.class,
        jdk.internal.event.X509CertificateEvent.class,

src/jdk.jfr/share/classes/jdk/jfr/internal/instrument/FileInputStreamInstrumentor.java:

 * See {@link JITracer} for an explanation of this code.
 */
@JIInstrumentationTarget("java.io.FileInputStream")
final class FileInputStreamInstrumentor {

    private FileInputStreamInstrumentor() {
    }

    private String path;

    @SuppressWarnings("deprecation")
    @JIInstrumentationMethod
    public int read() throws IOException {
        FileReadEvent event = FileReadEvent.EVENT.get();
        if (!event.isEnabled()) {
            return read();
        }
        int result = 0;
        try {
            event.begin();
            result = read();
            if (result < 0) {
                event.endOfFile = true;
            } else {
                event.bytesRead = 1;
            }
        } finally {
            event.path = path;
            event.commit();
            event.reset();
        }
        return result;
    }

    @SuppressWarnings("deprecation")
    @JIInstrumentationMethod
    public int read(byte b[]) throws IOException {
        FileReadEvent event = FileReadEvent.EVENT.get();
        if (!event.isEnabled()) {
            return read(b);
        }
        int bytesRead = 0;
        try {
            event.begin();
            bytesRead = read(b);
        } finally {
            if (bytesRead < 0) {
                event.endOfFile = true;
            } else {
                event.bytesRead = bytesRead;
            }
            event.path = path;
            event.commit();
            event.reset();
        }
        return bytesRead;
    }

    @SuppressWarnings("deprecation")
    @JIInstrumentationMethod
    public int read(byte b[], int off, int len) throws IOException {
        FileReadEvent event = FileReadEvent.EVENT.get();
        if (!event.isEnabled()) {
            return read(b, off, len);
        }
        int bytesRead = 0;
        try {
            event.begin();
            bytesRead = read(b, off, len);
        } finally {
            if (bytesRead < 0) {
                event.endOfFile = true;
            } else {

src/jdk.jfr/share/classes/jdk/jfr/internal/instrument/RandomAccessFileInstrumentor.java:

 * See {@link JITracer} for an explanation of this code.
 */
@JIInstrumentationTarget("java.io.RandomAccessFile")
final class RandomAccessFileInstrumentor {

    private RandomAccessFileInstrumentor() {
    }

    private String path;

    @SuppressWarnings("deprecation")
    @JIInstrumentationMethod
    public int read() throws IOException {
        FileReadEvent event = FileReadEvent.EVENT.get();
        if (!event.isEnabled()) {
            return read();
        }
        int result = 0;
        try {
            event.begin();
            result = read();
            if (result < 0) {
                event.endOfFile = true;
            } else {
                event.bytesRead = 1;
            }
        } finally {
            event.path = path;
            event.commit();
            event.reset();
        }
        return result;
    }

    @SuppressWarnings("deprecation")
    @JIInstrumentationMethod
    public int read(byte b[]) throws IOException {
        FileReadEvent event = FileReadEvent.EVENT.get();
        if (!event.isEnabled()) {
            return read(b);
        }
        int bytesRead = 0;
        try {
            event.begin();
            bytesRead = read(b);
        } finally {
            if (bytesRead < 0) {
                event.endOfFile = true;
            } else {
                event.bytesRead = bytesRead;
            }
            event.path = path;
            event.commit();
            event.reset();
        }
        return bytesRead;
    }

    @SuppressWarnings("deprecation")
    @JIInstrumentationMethod
    public int read(byte b[], int off, int len) throws IOException {
        FileReadEvent event = FileReadEvent.EVENT.get();
        if (!event.isEnabled()) {
            return read(b, off, len);
        }
        int bytesRead = 0;
        try {
            event.begin();
            bytesRead = read(b, off, len);
        } finally {
            if (bytesRead < 0) {
                event.endOfFile = true;
            } else {

src/jdk.jfr/share/classes/jdk/jfr/internal/instrument/FileChannelImplInstrumentor.java:

            event.begin();
            force(metaData);
        } finally {
            event.path = path;
            event.metaData = metaData;
            event.commit();
            event.reset();
        }
    }

    @SuppressWarnings("deprecation")
    @JIInstrumentationMethod
    public int read(ByteBuffer dst) throws IOException {
        FileReadEvent event = FileReadEvent.EVENT.get();
        if (!event.isEnabled()) {
            return read(dst);
        }
        int bytesRead = 0;
        try {
            event.begin();
            bytesRead = read(dst);
        } finally {
            if (bytesRead < 0) {
                event.endOfFile = true;
            } else {
                event.bytesRead = bytesRead;
            }
            event.path = path;
            event.commit();
            event.reset();
        }
        return bytesRead;
    }

    @SuppressWarnings("deprecation")
    @JIInstrumentationMethod
    public int read(ByteBuffer dst, long position) throws IOException {
        FileReadEvent event = FileReadEvent.EVENT.get();
        if (!event.isEnabled()) {
            return read(dst, position);
        }
        int bytesRead = 0;
        try {
            event.begin();
            bytesRead = read(dst, position);
        } finally {
            if (bytesRead < 0) {
                event.endOfFile = true;
            } else {
                event.bytesRead = bytesRead;
            }
            event.path = path;
            event.commit();
            event.reset();
        }
        return bytesRead;
    }

    @SuppressWarnings("deprecation")
    @JIInstrumentationMethod
    public long read(ByteBuffer[] dsts, int offset, int length) throws IOException {
        FileReadEvent event = FileReadEvent.EVENT.get();
        if (!event.isEnabled()) {
            return read(dsts, offset, length);
        }
        long bytesRead = 0;
        try {
            event.begin();
            bytesRead = read(dsts, offset, length);
        } finally {
            if (bytesRead < 0) {
                event.endOfFile = true;
            } else {

Configuration enabled stackTrace threshold
default true true 20 ms
profiling true true 10 ms

Field Type Description
path string Path Full path of the file
bytesRead long: bytes Bytes Read Number of bytes read from the file (possibly 0)
endOfFile boolean End of File If end of file was reached

Examples 2
bytesRead long: bytes
65536
endOfFile boolean
false
path string
[...]_1/code/experiments/jfreventcollector/harness-131340-18105539698102044895/apache-spark/log-regression/input.txt
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
162
lineNumber int
113
method Method
descriptor string
([BII)I
hidden boolean
false
modifiers int
1
name string
read
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/io/FileInputStream
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/io
type FrameType
JIT compiled
truncated boolean
false
startTime long: millis
273457008792
bytesRead long: bytes
65536
endOfFile boolean
false
path string
[...]_1/code/experiments/jfreventcollector/harness-130453-1906420335947283803/apache-spark/log-regression/input.txt
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
162
lineNumber int
113
method Method
descriptor string
([BII)I
hidden boolean
false
modifiers int
1
name string
read
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/io/FileInputStream
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/io
type FrameType
Interpreted
truncated boolean
false
startTime long: millis
233899060250

Java Application Statistics

JavaThreadStatistics

default profiling startTime duration every chunk 11 17 21 25 26

Category: Java Application / Statistics

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/jfr/periodic/jfrPeriodic.cpp:

 *
 *  If running inside a guest OS on top of a hypervisor in a virtualized environment,
 *  the total memory reported is the amount of memory configured for the guest OS by the hypervisor.
 */
TRACE_REQUEST_FUNC(PhysicalMemory) {
  u8 totalPhysicalMemory = os::physical_memory();
  EventPhysicalMemory event;
  event.set_totalSize(totalPhysicalMemory);
  event.set_usedSize(totalPhysicalMemory - os::available_memory());
  event.commit();
}

TRACE_REQUEST_FUNC(JavaThreadStatistics) {
  EventJavaThreadStatistics event;
  event.set_activeCount(ThreadService::get_live_thread_count());
  event.set_daemonCount(ThreadService::get_daemon_thread_count());
  event.set_accumulatedCount(ThreadService::get_total_thread_count());
  event.set_peakCount(ThreadService::get_peak_thread_count());
  event.commit();
}

TRACE_REQUEST_FUNC(ClassLoadingStatistics) {
  EventClassLoadingStatistics event;
  event.set_loadedClassCount(ClassLoadingService::loaded_class_count());
  event.set_unloadedClassCount(ClassLoadingService::unloaded_class_count());

Configuration enabled period
default true 1000 ms
profiling true 1000 ms

Field Type Description
activeCount long Active Threads Number of live active threads including both daemon and non-daemon threads
daemonCount long Daemon Threads Number of live daemon threads
accumulatedCount long Accumulated Threads Number of threads created and also started since JVM start
peakCount long Peak Threads Peak live thread count since JVM start or when peak count was reset

Examples 3
accumulatedCount long
1839
activeCount long
169
daemonCount long
168
peakCount long
324
startTime long: millis
254560650750
accumulatedCount long
1744
activeCount long
92
daemonCount long
91
peakCount long
324
startTime long: millis
267056018292
accumulatedCount long
2315
activeCount long
95
daemonCount long
94
peakCount long
357
startTime long: millis
245620234083

ClassLoadingStatistics

default profiling startTime duration every chunk 11 17 21 25 26

Category: Java Application / Statistics

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/jfr/periodic/jfrPeriodic.cpp:

  event.commit();
}

TRACE_REQUEST_FUNC(JavaThreadStatistics) {
  EventJavaThreadStatistics event;
  event.set_activeCount(ThreadService::get_live_thread_count());
  event.set_daemonCount(ThreadService::get_daemon_thread_count());
  event.set_accumulatedCount(ThreadService::get_total_thread_count());
  event.set_peakCount(ThreadService::get_peak_thread_count());
  event.commit();
}

TRACE_REQUEST_FUNC(ClassLoadingStatistics) {
  EventClassLoadingStatistics event;
  event.set_loadedClassCount(ClassLoadingService::loaded_class_count());
  event.set_unloadedClassCount(ClassLoadingService::unloaded_class_count());
  event.commit();
}

class JfrClassLoaderStatsClosure : public ClassLoaderStatsClosure {
public:
  JfrClassLoaderStatsClosure() : ClassLoaderStatsClosure(NULL) {}

  bool do_entry(oop const& key, ClassLoaderStats* const& cls) {
    const ClassLoaderData* this_cld = cls->_class_loader != NULL ?

Configuration enabled period
default true 1000 ms
profiling true 1000 ms

Field Type Description
loadedClassCount long Loaded Class Count Number of classes loaded since JVM start
unloadedClassCount long Unloaded Class Count Number of classes unloaded since JVM start

Examples 3
loadedClassCount long
131857
startTime long: millis
264811511250
unloadedClassCount long
4158
loadedClassCount long
139294
startTime long: millis
250660322416
unloadedClassCount long
9318
loadedClassCount long
139187
startTime long: millis
293799310792
unloadedClassCount long
9324

ClassLoaderStatistics

default profiling startTime duration every chunk 11 17 21 25 26

Category: Java Application / Statistics

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/jfr/periodic/jfrPeriodic.cpp:

  event.set_unloadedClassCount(ClassLoadingService::unloaded_class_count());
  event.commit();
}

class JfrClassLoaderStatsClosure : public ClassLoaderStatsClosure {
public:
  JfrClassLoaderStatsClosure() : ClassLoaderStatsClosure(NULL) {}

  bool do_entry(oop const& key, ClassLoaderStats* const& cls) {
    const ClassLoaderData* this_cld = cls->_class_loader != NULL ?
      java_lang_ClassLoader::loader_data_acquire(cls->_class_loader) : NULL;
    const ClassLoaderData* parent_cld = cls->_parent != NULL ?
      java_lang_ClassLoader::loader_data_acquire(cls->_parent) : NULL;
    EventClassLoaderStatistics event;
    event.set_classLoader(this_cld);
    event.set_parentClassLoader(parent_cld);
    event.set_classLoaderData((intptr_t)cls->_cld);
    event.set_classCount(cls->_classes_count);
    event.set_chunkSize(cls->_chunk_sz);
    event.set_blockSize(cls->_block_sz);
    event.set_unsafeAnonymousClassCount(cls->_anon_classes_count);
    event.set_unsafeAnonymousChunkSize(cls->_anon_chunk_sz);
    event.set_unsafeAnonymousBlockSize(cls->_anon_block_sz);
    event.commit();
    return true;

Configuration enabled period
default true everyChunk
profiling true everyChunk

Field Type Description
classLoader ClassLoader Class Loader Consider contributing a description to jfreventcollector.
parentClassLoader ClassLoader Parent Class Loader Consider contributing a description to jfreventcollector.
classLoaderData ulong: address ClassLoaderData Pointer Pointer to the ClassLoaderData structure in the JVM
classCount long Classes Number of loaded classes
chunkSize ulong: bytes Total Chunk Size Total size of all allocated metaspace chunks (each chunk has several blocks)
blockSize ulong: bytes Total Block Size Total size of all allocated metaspace blocks (each chunk has several blocks)
unsafeAnonymousClassCount long until JDK 15 Unsafe Anonymous Classes Number of loaded classes to support invokedynamic
unsafeAnonymousChunkSize ulong: bytes until JDK 15 Total Unsafe Anonymous Classes Chunk Size Total size of all allocated metaspace chunks for unsafe anonymous classes (each chunk has several blocks)
unsafeAnonymousBlockSize ulong: bytes until JDK 15 Total Unsafe Anonymous Classes Block Size Total size of all allocated metaspace blocks for unsafe anonymous classes (each chunk has several blocks)

Examples 3
blockSize ulong: bytes
3472
chunkSize ulong: bytes
4096
classCount long
1
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
0
name string
jdk/internal/reflect/DelegatingClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
jdk/internal/reflect
classLoaderData ulong: address
105553179034240
parentClassLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/net
startTime long: millis
230209996583
blockSize ulong: bytes
0
chunkSize ulong: bytes
0
classCount long
0
classLoader ClassLoader
null
classLoaderData ulong: address
0
parentClassLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/net
hidden boolean
false
modifiers int
1
name string
org/apache/spark/util/MutableURLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/net
location string
null
name string
null
version string
null
name string
org/apache/spark/util
startTime long: millis
242226560750
blockSize ulong: bytes
3160
chunkSize ulong: bytes
4096
classCount long
1
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
0
name string
jdk/internal/reflect/DelegatingClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
jdk/internal/reflect
classLoaderData ulong: address
105553120266432
parentClassLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/net
startTime long: millis
199126693166

ThreadAllocationStatistics

default profiling startTime every chunk 11 17 21 25 26

Category: Java Application / Statistics

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/jfr/periodic/jfrPeriodic.cpp:

  GrowableArray<traceid> thread_ids(initial_size);
  JfrTicks time_stamp = JfrTicks::now();
  {
    // Collect allocation statistics while holding threads lock
    MutexLockerEx ml(Threads_lock);
    for (JavaThreadIteratorWithHandle jtiwh; JavaThread *jt = jtiwh.next(); ) {
      allocated.append(jt->cooked_allocated_bytes());
      thread_ids.append(JFR_THREAD_ID(jt));
    }
  }

  // Write allocation statistics to buffer.
  for(int i = 0; i < thread_ids.length(); i++) {
    EventThreadAllocationStatistics event(UNTIMED);
    event.set_allocated(allocated.at(i));
    event.set_thread(thread_ids.at(i));
    event.set_endtime(time_stamp);
    event.commit();
  }
}

/**
 *  PhysicalMemory event represents:
 *
 *  @totalSize == The amount of physical memory (hw) installed and reported by the OS, in bytes.

Configuration enabled period
default true everyChunk
profiling true everyChunk

Field Type Description
allocated ulong: bytes Allocated Approximate number of bytes allocated since thread start
thread Thread Thread Consider contributing a description to jfreventcollector.

Examples 3
allocated ulong: bytes
272
startTime long: millis
242226660042
thread Thread
group ThreadGroup
name string
main
parent ThreadGroup
name string
system
parent ThreadGroup
null
javaName string
scala-execution-context-global-223
javaThreadId long
223
osName string
scala-execution-context-global-223
osThreadId long
84235
virtual boolean
false
allocated ulong: bytes
2516472
startTime long: millis
199126884041
thread Thread
group ThreadGroup
name string
main
parent ThreadGroup
name string
system
parent ThreadGroup
null
javaName string
RxComputationThreadPool-5
javaThreadId long
1135
osName string
RxComputationThreadPool-5
osThreadId long
179739
virtual boolean
false
allocated ulong: bytes
272
startTime long: millis
230210215167
thread Thread
group ThreadGroup
name string
main
parent ThreadGroup
name string
system
parent ThreadGroup
null
javaName string
scala-execution-context-global-227
javaThreadId long
227
osName string
scala-execution-context-global-227
osThreadId long
130311
virtual boolean
false

ExceptionStatistics

default profiling startTime duration stackTrace 11 17 21 25 26

Source src/jdk.jfr/share/classes/jdk/jfr/events/ExceptionStatisticsEvent.java

Category: Java Application / Statistics

Number of objects derived from java.lang.Throwable that have been created

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/jdk.jfr/share/classes/jdk/jfr/events/ExceptionStatisticsEvent.java:

package jdk.jfr.events;

import jdk.jfr.Category;
import jdk.jfr.Description;
import jdk.jfr.Label;
import jdk.jfr.Name;
import jdk.jfr.StackTrace;
import jdk.jfr.internal.Type;

@Name(Type.EVENT_NAME_PREFIX + "ExceptionStatistics")
@Label("Exception Statistics")
@Category({ "Java Application", "Statistics" })
@Description("Number of objects derived from java.lang.Throwable that have been created")
@StackTrace(false)
public final class ExceptionStatisticsEvent extends AbstractJDKEvent {

    @Label("Exceptions Created")
    public long throwables;
}

src/jdk.jfr/share/classes/jdk/jfr/internal/instrument/JDKEvents.java:

        SecurityPropertyModificationEvent.class,
        TLSHandshakeEvent.class,
        X509CertificateEvent.class,
        X509ValidationEvent.class
    };

    private static final Class<?>[] eventClasses = {
        FileForceEvent.class,
        FileReadEvent.class,
        FileWriteEvent.class,
        SocketReadEvent.class,
        SocketWriteEvent.class,
        ExceptionThrownEvent.class,
        ExceptionStatisticsEvent.class,
        ErrorThrownEvent.class,
        ActiveSettingEvent.class,
        ActiveRecordingEvent.class,
        jdk.internal.event.SecurityPropertyModificationEvent.class,
        jdk.internal.event.TLSHandshakeEvent.class,
        jdk.internal.event.X509CertificateEvent.class,
        jdk.internal.event.X509ValidationEvent.class
    };

    // This is a list of the classes with instrumentation code that should be applied.
    private static final Class<?>[] instrumentationClasses = new Class<?>[] {

src/jdk.jfr/share/classes/jdk/jfr/internal/instrument/JDKEvents.java:

    private static boolean initializationTriggered;

    @SuppressWarnings("unchecked")
    public synchronized static void initialize() {
        try {
            if (initializationTriggered == false) {
                for (Class<?> mirrorEventClass : mirrorEventClasses) {
                    SecuritySupport.registerMirror(((Class<? extends Event>)mirrorEventClass));
                }
                for (Class<?> eventClass : eventClasses) {
                    SecuritySupport.registerEvent((Class<? extends Event>) eventClass);
                }
                initializationTriggered = true;
                RequestEngine.addTrustedJDKHook(ExceptionStatisticsEvent.class, emitExceptionStatistics);
            }
        } catch (Exception e) {
            Logger.log(LogTag.JFR_SYSTEM, LogLevel.WARN, "Could not initialize JDK events. " + e.getMessage());
        }
    }

    public static void addInstrumentation() {
        try {
            List<Class<?>> list = new ArrayList<>();
            for (int i = 0; i < instrumentationClasses.length; i++) {
                JIInstrumentationTarget tgt = instrumentationClasses[i].getAnnotation(JIInstrumentationTarget.class);

src/jdk.jfr/share/classes/jdk/jfr/internal/instrument/JDKEvents.java:

                targetClasses[i] = clazz;
                list.add(clazz);
            }
            list.add(java.lang.Throwable.class);
            list.add(java.lang.Error.class);
            Logger.log(LogTag.JFR_SYSTEM, LogLevel.INFO, "Retransformed JDK classes");
            jvm.retransformClasses(list.toArray(new Class<?>[list.size()]));
        } catch (Exception e) {
            Logger.log(LogTag.JFR_SYSTEM, LogLevel.WARN, "Could not add instrumentation for JDK events. " + e.getMessage());
        }
    }

    private static void emitExceptionStatistics() {
        ExceptionStatisticsEvent t = new ExceptionStatisticsEvent();
        t.throwables = ThrowableTracer.numThrowables();
        t.commit();
    }

    @SuppressWarnings("deprecation")
    public static byte[] retransformCallback(Class<?> klass, byte[] oldBytes) throws Throwable {
        if (java.lang.Throwable.class == klass) {
            Logger.log(LogTag.JFR_SYSTEM, LogLevel.TRACE, "Instrumenting java.lang.Throwable");
            return ConstructorTracerWriter.generateBytes(java.lang.Throwable.class, oldBytes);
        }

Configuration enabled period
default true 1000 ms
profiling true 1000 ms

Field Type Description
throwables long Exceptions Created

Examples 3
stackTrace StackTrace
null
startTime long: millis
242598256875
throwables long
2445601
stackTrace StackTrace
null
startTime long: millis
276149984125
throwables long
2435469
stackTrace StackTrace
null
startTime long: millis
258393670083
throwables long
2436447

Java Development Kit

X509Certificate

startTime duration stackTrace 11 17 21 25 26

Source src/jdk.jfr/share/classes/jdk/jfr/events/X509CertificateEvent.java

Category: Java Development Kit / Security

Details of X.509 Certificate parsed by JDK

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/jdk.jfr/share/classes/jdk/jfr/events/X509CertificateEvent.java:

package jdk.jfr.events;

import jdk.jfr.*;
import jdk.jfr.internal.MirrorEvent;

@Category({"Java Development Kit", "Security"})
@Label("X509 Certificate")
@Name("jdk.X509Certificate")
@Description("Details of X.509 Certificate parsed by JDK")
@MirrorEvent(className = "jdk.internal.event.X509CertificateEvent")
public final class X509CertificateEvent extends AbstractJDKEvent {
    @Label("Signature Algorithm")
    public String algorithm;

    @Label("Serial Number")
    public String serialNumber;

    @Label("Subject")
    public String subject;

    @Label("Issuer")
    public String issuer;

    @Label("Key Type")

src/jdk.jfr/share/classes/jdk/jfr/internal/instrument/JDKEvents.java:

public final class JDKEvents {

    private static final Class<?>[] mirrorEventClasses = {
        SecurityPropertyModificationEvent.class,
        TLSHandshakeEvent.class,
        X509CertificateEvent.class,
        X509ValidationEvent.class
    };

    private static final Class<?>[] eventClasses = {
        FileForceEvent.class,
        FileReadEvent.class,
        FileWriteEvent.class,
        SocketReadEvent.class,
        SocketWriteEvent.class,
        ExceptionThrownEvent.class,
        ExceptionStatisticsEvent.class,

src/java.base/share/classes/jdk/internal/event/X509CertificateEvent.java:

package jdk.internal.event;


/**
 * Event recording details of X.509 Certificate.
 */

public final class X509CertificateEvent extends Event {
    public String algorithm;
    public String serialNumber;
    public String subject;
    public String issuer;
    public String keyType;
    public int keyLength;
    public long certificateId;
    public long validFrom;
    public long validUntil;
}

src/java.base/share/classes/sun/security/provider/X509Factory.java:

                length = (highByte << 24 ) | (nextByte << 16) |
                        (midByte << 8) | lowByte;
            } else { // ignore longer length forms
                throw new IOException("Invalid BER/DER data (too huge?)");
            }
            if (readFully(is, bout, length) != length) {
                throw new IOException("Incomplete BER/DER data");
            }
        }
        return tag;
    }

    private void commitEvent(X509CertImpl info) {
        X509CertificateEvent xce = new X509CertificateEvent();
        if (xce.shouldCommit() || EventHelper.isLoggingSecurity()) {
            PublicKey pKey = info.getPublicKey();
            String algId = info.getSigAlgName();
            String serNum = info.getSerialNumber().toString(16);
            String subject = info.getSubjectDN().getName();
            String issuer = info.getIssuerDN().getName();
            String keyType = pKey.getAlgorithm();
            int length = KeyUtil.getKeySize(pKey);
            int hashCode = info.hashCode();
            long beginDate = info.getNotBefore().getTime();
            long endDate = info.getNotAfter().getTime();

Configuration enabled stackTrace
default false true
profiling false true

Field Type Description
algorithm string Signature Algorithm
serialNumber string Serial Number Consider contributing a description to jfreventcollector.
subject string Subject Consider contributing a description to jfreventcollector.
issuer string Issuer Consider contributing a description to jfreventcollector.
keyType string Key Type Consider contributing a description to jfreventcollector.
keyLength int Key Length
certificateId long: certificateId Certificate Id
validFrom long: epochmillis Valid From
validUntil long: epochmillis Valid Until

Examples 3
algorithm string
SHA1withDSA
certificateId long: certificateId
3045411335
issuer string
CN=Unknown, OU=Unknown, O=Unknown, L=Unknown, ST=Unknown, C=Unknown
keyLength int
1024
keyType string
DSA
serialNumber string
46:10:1f:71
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
185
lineNumber int
128
method Method
descriptor string
(Ljava/security/cert/Certificate;)V
hidden boolean
false
modifiers int
9
name string
tryCommitCertEvent
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
17
name string
sun/security/jca/JCAUtil
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
sun/security/jca
type FrameType
Interpreted
truncated boolean
false
startTime long: millis
272057185083
subject string
CN=Unknown, OU=Unknown, O=Unknown, L=Unknown, ST=Unknown, C=Unknown
validFrom long: epochmillis
1175461745000
validUntil long: epochmillis
4329061745000
algorithm string
SHA1withDSA
certificateId long: certificateId
3045411335
issuer string
CN=Unknown, OU=Unknown, O=Unknown, L=Unknown, ST=Unknown, C=Unknown
keyLength int
1024
keyType string
DSA
serialNumber string
46:10:1f:71
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
185
lineNumber int
128
method Method
descriptor string
(Ljava/security/cert/Certificate;)V
hidden boolean
false
modifiers int
9
name string
tryCommitCertEvent
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
17
name string
sun/security/jca/JCAUtil
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
sun/security/jca
type FrameType
Interpreted
truncated boolean
false
startTime long: millis
252845703292
subject string
CN=Unknown, OU=Unknown, O=Unknown, L=Unknown, ST=Unknown, C=Unknown
validFrom long: epochmillis
1175461745000
validUntil long: epochmillis
4329061745000
algorithm string
SHA1withDSA
certificateId long: certificateId
3045411335
issuer string
CN=Unknown, OU=Unknown, O=Unknown, L=Unknown, ST=Unknown, C=Unknown
keyLength int
1024
keyType string
DSA
serialNumber string
46:10:1f:71
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
185
lineNumber int
128
method Method
descriptor string
(Ljava/security/cert/Certificate;)V
hidden boolean
false
modifiers int
9
name string
tryCommitCertEvent
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
17
name string
sun/security/jca/JCAUtil
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
sun/security/jca
type FrameType
Interpreted
truncated boolean
false
startTime long: millis
232653834333
subject string
CN=Unknown, OU=Unknown, O=Unknown, L=Unknown, ST=Unknown, C=Unknown
validFrom long: epochmillis
1175461745000
validUntil long: epochmillis
4329061745000

TLSHandshake

startTime duration stackTrace 11 17 21 25 26

Source src/jdk.jfr/share/classes/jdk/jfr/events/TLSHandshakeEvent.java

Category: Java Development Kit / Security

Parameters used in TLS Handshake

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/jdk.jfr/share/classes/jdk/jfr/events/TLSHandshakeEvent.java:

package jdk.jfr.events;

import jdk.jfr.Category;
import jdk.jfr.Description;
import jdk.jfr.Label;
import jdk.jfr.Name;
import jdk.jfr.internal.MirrorEvent;

@Category({"Java Development Kit", "Security"})
@Label("TLS Handshake")
@Name("jdk.TLSHandshake")
@Description("Parameters used in TLS Handshake")
@MirrorEvent(className = "jdk.internal.event.TLSHandshakeEvent")
public final class TLSHandshakeEvent extends AbstractJDKEvent {
    @Label("Peer Host")
    public String peerHost;

    @Label("Peer Port")
    public int peerPort;

    @Label("Protocol Version")
    public String protocolVersion;

    @Label("Cipher Suite")
    public String cipherSuite;

src/jdk.jfr/share/classes/jdk/jfr/internal/instrument/JDKEvents.java:

public final class JDKEvents {

    private static final Class<?>[] mirrorEventClasses = {
        SecurityPropertyModificationEvent.class,
        TLSHandshakeEvent.class,
        X509CertificateEvent.class,
        X509ValidationEvent.class
    };

    private static final Class<?>[] eventClasses = {
        FileForceEvent.class,
        FileReadEvent.class,
        FileWriteEvent.class,
        SocketReadEvent.class,
        SocketWriteEvent.class,
        ExceptionThrownEvent.class,

src/java.base/share/classes/sun/security/ssl/Finished.java:

            //
            // produce
            if (SSLLogger.isOn && SSLLogger.isOn("ssl,handshake")) {
                SSLLogger.fine(
                "Sending new session ticket");
            }
            NewSessionTicket.kickstartProducer.produce(shc);

        }
    }

    private static void recordEvent(SSLSessionImpl session) {
        TLSHandshakeEvent event = new TLSHandshakeEvent();
        if (event.shouldCommit() || EventHelper.isLoggingSecurity()) {
            int peerCertificateId = 0;
            try {
                // use hash code for Id
                peerCertificateId = session
                        .getCertificateChain()[0]
                        .hashCode();
            } catch (SSLPeerUnverifiedException e) {
                 // not verified msg
            }
            if (event.shouldCommit()) {

src/java.base/share/classes/jdk/internal/event/TLSHandshakeEvent.java:

package jdk.internal.event;

/**
 * Event recording details of successful TLS handshakes.
 */

public final class TLSHandshakeEvent extends Event {
    public String peerHost;
    public int peerPort;
    public String protocolVersion;
    public String cipherSuite;
    public long certificateId;
}

Configuration enabled stackTrace
default false true
profiling false true

Field Type Description
peerHost string Peer Host Consider contributing a description to jfreventcollector.
peerPort int Peer Port
protocolVersion string Protocol Version Consider contributing a description to jfreventcollector.
cipherSuite string Cipher Suite Consider contributing a description to jfreventcollector.
certificateId long: certificateId Certificate Id Peer Certificate Id

X509Validation

startTime duration stackTrace 11 17 21 25 26

Source src/jdk.jfr/share/classes/jdk/jfr/events/X509ValidationEvent.java

Category: Java Development Kit / Security

Serial numbers from X.509 Certificates forming chain of trust

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/jdk.jfr/share/classes/jdk/jfr/events/X509ValidationEvent.java:

package jdk.jfr.events;

import jdk.jfr.*;
import jdk.jfr.internal.MirrorEvent;

@Category({"Java Development Kit", "Security"})
@Label("X509 Validation")
@Name("jdk.X509Validation")
@Description("Serial numbers from X.509 Certificates forming chain of trust")
@MirrorEvent(className = "jdk.internal.event.X509ValidationEvent")
public final class X509ValidationEvent extends AbstractJDKEvent {
    @CertificateId
    @Label("Certificate Id")
    public long certificateId;

    @Label("Certificate Position")
    @Description("Certificate position in chain of trust, 1 = trust anchor")
    public int certificatePosition;

    @Label("Validation Counter")
    public long validationCounter;
}

src/jdk.jfr/share/classes/jdk/jfr/internal/instrument/JDKEvents.java:

public final class JDKEvents {

    private static final Class<?>[] mirrorEventClasses = {
        SecurityPropertyModificationEvent.class,
        TLSHandshakeEvent.class,
        X509CertificateEvent.class,
        X509ValidationEvent.class
    };

    private static final Class<?>[] eventClasses = {
        FileForceEvent.class,
        FileReadEvent.class,
        FileWriteEvent.class,
        SocketReadEvent.class,
        SocketWriteEvent.class,
        ExceptionThrownEvent.class,
        ExceptionStatisticsEvent.class,
        ErrorThrownEvent.class,

src/java.base/share/classes/sun/security/provider/certpath/PKIXCertPathValidator.java:

        // only add a RevocationChecker if revocation is enabled and
        // a PKIXRevocationChecker has not already been added
        if (params.revocationEnabled() && !revCheckerAdded) {
            certPathCheckers.add(new RevocationChecker(anchor, params));
        }
        // add user-specified checkers
        certPathCheckers.addAll(checkers);

        PKIXMasterCertPathValidator.validate(params.certPath(),
                                             params.certificates(),
                                             certPathCheckers);

        X509ValidationEvent xve = new X509ValidationEvent();
        if (xve.shouldCommit() || EventHelper.isLoggingSecurity()) {
            int[] certIds = params.certificates().stream()
                    .mapToInt(x -> x.hashCode())
                    .toArray();
            int anchorCertId =
                    anchor.getTrustedCert().hashCode();
            if (xve.shouldCommit()) {
                xve.certificateId = anchorCertId;
                int certificatePos = 1; //anchor cert
                xve.certificatePosition = certificatePos;
                xve.validationCounter = validationCounter.incrementAndGet();

src/java.base/share/classes/jdk/internal/event/X509ValidationEvent.java:

package jdk.internal.event;

/**
 * Event recording details of X.509 Certificate serial numbers
 * used in X509 cert path validation.
 */

public final class X509ValidationEvent extends Event {
    public long certificateId;
    public int certificatePosition;
    public long validationCounter;
}

Configuration enabled stackTrace
default false true
profiling false true

Field Type Description
certificateId long: certificateId Certificate Id
certificatePosition int Certificate Position Certificate position in chain of trust, 1 = trust anchor
validationCounter long Validation Counter

SecurityPropertyModification

startTime duration stackTrace 11 17 21 25 26

Source src/jdk.jfr/share/classes/jdk/jfr/events/SecurityPropertyModificationEvent.java

Category: Java Development Kit / Security

Modification of Security property

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/java.base/share/classes/java/security/Security.java:

     *          if a security manager exists and its {@link
     *          java.lang.SecurityManager#checkPermission} method
     *          denies access to set the specified security property value
     * @throws  NullPointerException if key or datum is null
     *
     * @see #getProperty
     * @see java.security.SecurityPermission
     */
    public static void setProperty(String key, String datum) {
        check("setProperty." + key);
        props.put(key, datum);
        invalidateSMCache(key);  /* See below. */

        SecurityPropertyModificationEvent spe = new SecurityPropertyModificationEvent();
        // following is a no-op if event is disabled
        spe.key = key;
        spe.value = datum;
        spe.commit();

        if (EventHelper.isLoggingSecurity()) {
            EventHelper.logSecurityPropertyEvent(key, datum);
        }
    }

    /*

src/jdk.jfr/share/classes/jdk/jfr/events/SecurityPropertyModificationEvent.java:

package jdk.jfr.events;

import jdk.jfr.*;
import jdk.jfr.internal.MirrorEvent;

@Category({"Java Development Kit", "Security"})
@Label("Security Property Modification")
@Name("jdk.SecurityPropertyModification")
@Description("Modification of Security property")
@MirrorEvent(className = "jdk.internal.event.SecurityPropertyModificationEvent")
public final class SecurityPropertyModificationEvent extends AbstractJDKEvent {
    @Label("Key")
    public String key;

    @Label("Value")
    public String value;
}

src/jdk.jfr/share/classes/jdk/jfr/internal/instrument/JDKEvents.java:

public final class JDKEvents {

    private static final Class<?>[] mirrorEventClasses = {
        SecurityPropertyModificationEvent.class,
        TLSHandshakeEvent.class,
        X509CertificateEvent.class,
        X509ValidationEvent.class
    };

    private static final Class<?>[] eventClasses = {
        FileForceEvent.class,
        FileReadEvent.class,
        FileWriteEvent.class,
        SocketReadEvent.class,
        SocketWriteEvent.class,

src/java.base/share/classes/jdk/internal/event/SecurityPropertyModificationEvent.java:

package jdk.internal.event;

/**
 * Event details relating to the modification of a Security property.
 */

public final class SecurityPropertyModificationEvent extends Event {
    public String key;
    public String value;
}

Configuration enabled stackTrace
default false true
profiling false true

Field Type Description
key string Key Consider contributing a description to jfreventcollector.
value string Value Consider contributing a description to jfreventcollector.

Operating System

OSInformation

default profiling startTime duration end of every chunk 11 17 21 25 26

Category: Operating System

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/jfr/periodic/jfrPeriodic.cpp:

  event.set_jvmVersion(VM_Version::internal_vm_info_string());
  event.set_javaArguments(Arguments::java_command());
  event.set_jvmArguments(Arguments::jvm_args());
  event.set_jvmFlags(Arguments::jvm_flags());
  event.set_jvmStartTime(Management::vm_init_done_time());
  event.set_pid(os::current_process_id());
  event.commit();
 }

TRACE_REQUEST_FUNC(OSInformation) {
  ResourceMark rm;
  char* os_name = NEW_RESOURCE_ARRAY(char, 2048);
  JfrOSInterface::os_version(&os_name);
  EventOSInformation event;
  event.set_osVersion(os_name);
  event.commit();
}

TRACE_REQUEST_FUNC(ModuleRequire) {
  JfrModuleEvent::generate_module_dependency_events();
}

TRACE_REQUEST_FUNC(ModuleExport) {
  JfrModuleEvent::generate_module_export_events();
}

Configuration enabled period
default true beginChunk
profiling true beginChunk

Field Type Description
osVersion string OS Version

Examples 3
osVersion string
uname: Darwin 24.6.0 Darwin Kernel Version 24.6.0: Mon Jul 14 11:30:40 PDT 2025; root:xnu-11417.140.69~1/RELEASE_ARM64_T6041 arm64
startTime long: millis
287137243792
osVersion string
uname: Darwin 24.6.0 Darwin Kernel Version 24.6.0: Mon Jul 14 11:30:40 PDT 2025; root:xnu-11417.140.69~1/RELEASE_ARM64_T6041 arm64
startTime long: millis
217937017583
osVersion string
uname: Darwin 24.6.0 Darwin Kernel Version 24.6.0: Mon Jul 14 11:30:40 PDT 2025; root:xnu-11417.140.69~1/RELEASE_ARM64_T6041 arm64
startTime long: millis
269257990000

InitialEnvironmentVariable

default profiling startTime end of every chunk 11 17 21 25 26

Category: Operating System

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/jfr/periodic/jfrOSInterface.cpp:

int JfrOSInterface::cpu_loads_process(double* jvm_user_load, double* jvm_kernel_load, double* system_total_load){
  return instance()._impl->cpu_loads_process(jvm_user_load, jvm_kernel_load, system_total_load);
}

int JfrOSInterface::os_version(char** os_version) {
  return instance()._impl->os_version(os_version);
}

int JfrOSInterface::generate_initial_environment_variable_events() {
  if (environ == NULL) {
    return OS_ERR;
  }

  if (EventInitialEnvironmentVariable::is_enabled()) {
    // One time stamp for all events, so they can be grouped together
    JfrTicks time_stamp = JfrTicks::now();
    for (char** p = environ; *p != NULL; p++) {
      char* variable = *p;
      char* equal_sign = strchr(variable, '=');
      if (equal_sign != NULL) {
        // Extract key/value
        ResourceMark rm;
        ptrdiff_t key_length = equal_sign - variable;
        char* key = NEW_RESOURCE_ARRAY(char, key_length + 1);
        char* value = equal_sign + 1;
        strncpy(key, variable, key_length);
        key[key_length] = '\0';
        EventInitialEnvironmentVariable event(UNTIMED);
        event.set_endtime(time_stamp);
        event.set_key(key);
        event.set_value(value);
        event.commit();
      }
    }
  }
  return OS_OK;
}

int JfrOSInterface::system_processes(SystemProcess** sys_processes, int* no_of_sys_processes) {

Configuration enabled period
default true beginChunk
profiling true beginChunk

Field Type Description
key string Key
value string Value

Examples 3
key string
ANDROID_HOME
startTime long: millis
247315613958
value string
[...]_1/.android
key string
AUTOJUMP_ERROR_PATH
startTime long: millis
199116091500
value string
[...]_1/Library/autojump/errors.log
key string
MAVEN_HOME
startTime long: millis
232720215500
value string
[...]_1/.sdkman/candidates/maven/current

SystemProcess

default profiling startTime duration end of every chunk 11 17 21 25 26

Category: Operating System

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/jfr/periodic/jfrPeriodic.cpp:

    while (processes != NULL) {
      SystemProcess* tmp = processes;
      const char* info = processes->command_line();
      if (info == NULL) {
         info = processes->path();
      }
      if (info == NULL) {
         info = processes->name();
      }
      if (info == NULL) {
         info = "?";
      }
      jio_snprintf(pid_buf, sizeof(pid_buf), "%d", processes->pid());
      EventSystemProcess event(UNTIMED);
      event.set_pid(pid_buf);
      event.set_commandLine(info);
      event.set_starttime(start_time);
      event.set_endtime(end_time);
      event.commit();
      processes = processes->next();
      delete tmp;
    }
  }
}

Configuration enabled period
default true endChunk
profiling true endChunk

Field Type Description
pid string Process Identifier
commandLine string Command Line

Examples 3
commandLine string
/usr/libexec/airportd
pid string
595
startTime long: millis
200088120250
commandLine string
/usr/sbin/distnoted
pid string
622
startTime long: millis
243796269167
commandLine string
/usr/libexec/endpointsecurityd
pid string
526
startTime long: millis
231199181958

CPUInformation

default profiling startTime duration end of every chunk 11 17 21 25 26

Category: Operating System / Processor

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/jfr/periodic/jfrPeriodic.cpp:

TRACE_REQUEST_FUNC(CPUInformation) {
  CPUInformation cpu_info;
  int ret_val = JfrOSInterface::cpu_information(cpu_info);
  if (ret_val == OS_ERR) {
    log_debug(jfr, system)( "Unable to generate requestable event CPUInformation");
    return;
  }
  if (ret_val == FUNCTIONALITY_NOT_IMPLEMENTED) {
     return;
  }
  if (ret_val == OS_OK) {
    EventCPUInformation event;
    event.set_cpu(cpu_info.cpu_name());
    event.set_description(cpu_info.cpu_description());
    event.set_sockets(cpu_info.number_of_sockets());
    event.set_cores(cpu_info.number_of_cores());
    event.set_hwThreads(cpu_info.number_of_hardware_threads());
    event.commit();
  }
}

TRACE_REQUEST_FUNC(CPULoad) {
  double u = 0; // user time

Configuration enabled period
default true beginChunk
profiling true beginChunk

Field Type Description
cpu string Type
description string Description
sockets uint Sockets
cores uint Cores
hwThreads uint Hardware Threads

Examples 3
cores uint
12
cpu string
AArch64
description string
AArch64 0x61:0x0:0x17d5b93a:0, fp, asimd, aes, pmull, sha1, sha256, crc32, lse, sha3, sha512
hwThreads uint
12
sockets uint
12
startTime long: millis
289840832333
cores uint
12
cpu string
AArch64
description string
AArch64 0x61:0x0:0x17d5b93a:0, fp, asimd, aes, pmull, sha1, sha256, crc32, lse, sha3, sha512
hwThreads uint
12
sockets uint
12
startTime long: millis
230199158417
cores uint
12
cpu string
AArch64
description string
AArch64 0x61:0x0:0x17d5b93a:0, fp, asimd, aes, pmull, sha1, sha256, crc32, lse, sha3, sha512
hwThreads uint
12
sockets uint
12
startTime long: millis
248885929083

CPUTimeStampCounter

default profiling startTime duration end of every chunk 11 17 21 25 26

Category: Operating System / Processor

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/jfr/periodic/jfrPeriodic.cpp:

    event.commit();
  }
}

TRACE_REQUEST_FUNC(ThreadCPULoad) {
  JfrThreadCPULoadEvent::send_events();
}

TRACE_REQUEST_FUNC(NetworkUtilization) {
  JfrNetworkUtilization::send_events();
}

TRACE_REQUEST_FUNC(CPUTimeStampCounter) {
  EventCPUTimeStampCounter event;
  event.set_fastTimeEnabled(JfrTime::is_ft_enabled());
  event.set_fastTimeAutoEnabled(JfrTime::is_ft_supported());
  event.set_osFrequency(os::elapsed_frequency());
  event.set_fastTimeFrequency(JfrTime::frequency());
  event.commit();
}

TRACE_REQUEST_FUNC(SystemProcess) {
  char pid_buf[16];
  SystemProcess* processes = NULL;
  int num_of_processes = 0;

Configuration enabled period
default true beginChunk
profiling true beginChunk

Field Type Description
fastTimeEnabled boolean Fast Time
fastTimeAutoEnabled boolean Trusted Platform
osFrequency long: hertz OS Frequency
fastTimeFrequency long: hertz Fast Time Frequency

Examples 3
fastTimeAutoEnabled boolean
false
fastTimeEnabled boolean
false
fastTimeFrequency long: hertz
1000000000
osFrequency long: hertz
1000000000
startTime long: millis
289840832792
fastTimeAutoEnabled boolean
false
fastTimeEnabled boolean
false
fastTimeFrequency long: hertz
1000000000
osFrequency long: hertz
1000000000
startTime long: millis
260705816208
fastTimeAutoEnabled boolean
false
fastTimeEnabled boolean
false
fastTimeFrequency long: hertz
1000000000
osFrequency long: hertz
1000000000
startTime long: millis
217937027583

CPULoad

default profiling startTime duration every chunk 11 17 21 25 26

Category: Operating System / Processor

OS CPU Load

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/jfr/periodic/jfrPeriodic.cpp:

TRACE_REQUEST_FUNC(CPULoad) {
  double u = 0; // user time
  double s = 0; // kernel time
  double t = 0; // total time
  int ret_val = JfrOSInterface::cpu_loads_process(&u, &s, &t);
  if (ret_val == OS_ERR) {
    log_debug(jfr, system)( "Unable to generate requestable event CPULoad");
    return;
  }
  if (ret_val == OS_OK) {
    EventCPULoad event;
    event.set_jvmUser((float)u);
    event.set_jvmSystem((float)s);
    event.set_machineTotal((float)t);
    event.commit();
  }
}

TRACE_REQUEST_FUNC(ThreadCPULoad) {
  JfrThreadCPULoadEvent::send_events();
}

Configuration enabled period
default true 1000 ms
profiling true 1000 ms

Field Type Description
jvmUser float: percentage JVM User
jvmSystem float: percentage JVM System
machineTotal float: percentage Machine Total

Examples 3
jvmSystem float: percentage
0.0052083335
jvmUser float: percentage
0.23842593
machineTotal float: percentage
0.30221704
startTime long: millis
286046188625
jvmSystem float: percentage
0.029545454
jvmUser float: percentage
0.15530303
machineTotal float: percentage
0.26981708
startTime long: millis
259497744583
jvmSystem float: percentage
0.009144771
jvmUser float: percentage
0.27150953
machineTotal float: percentage
0.35278925
startTime long: millis
212496406791

ThreadCPULoad

default profiling startTime duration eventThread every chunk 11 17 21 25 26

Category: Operating System / Processor

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/jfr/periodic/jfrThreadCPULoadEvent.cpp:

int JfrThreadCPULoadEvent::get_processor_count() {
  int cur_processor_count = os::active_processor_count();
  int last_processor_count = _last_active_processor_count;
  _last_active_processor_count = cur_processor_count;

  // If the number of processors decreases, we don't know at what point during
  // the sample interval this happened, so use the largest number to try
  // to avoid percentages above 100%
  return MAX2(cur_processor_count, last_processor_count);
}

// Returns false if the thread has not been scheduled since the last call to updateEvent
// (i.e. the delta for both system and user time is 0 milliseconds)
bool JfrThreadCPULoadEvent::update_event(EventThreadCPULoad& event, JavaThread* thread, jlong cur_wallclock_time, int processor_count) {
  JfrThreadLocal* const tl = thread->jfr_thread_local();

  jlong cur_cpu_time = os::thread_cpu_time(thread, true);
  jlong prev_cpu_time = tl->get_cpu_time();

  jlong prev_wallclock_time = tl->get_wallclock_time();
  tl->set_wallclock_time(cur_wallclock_time);

  // Threshold of 1 ms
  if (cur_cpu_time - prev_cpu_time < 1 * NANOSECS_PER_MILLISEC) {
    return false;

src/hotspot/share/jfr/periodic/jfrThreadCPULoadEvent.cpp:

void JfrThreadCPULoadEvent::send_events() {
  Thread* periodic_thread = Thread::current();
  JfrThreadLocal* const periodic_thread_tl = periodic_thread->jfr_thread_local();
  traceid periodic_thread_id = periodic_thread_tl->thread_id();
  const int processor_count = JfrThreadCPULoadEvent::get_processor_count();
  JfrTicks event_time = JfrTicks::now();
  jlong cur_wallclock_time = JfrThreadCPULoadEvent::get_wallclock_time();

  JavaThreadIteratorWithHandle jtiwh;
  while (JavaThread* jt = jtiwh.next()) {
    EventThreadCPULoad event(UNTIMED);
    if (JfrThreadCPULoadEvent::update_event(event, jt, cur_wallclock_time, processor_count)) {
      event.set_starttime(event_time);
      if (jt != periodic_thread) {
        // Commit reads the thread id from this thread's trace data, so put it there temporarily
        periodic_thread_tl->set_thread_id(JFR_THREAD_ID(jt));
      } else {
        periodic_thread_tl->set_thread_id(periodic_thread_id);
      }
      event.commit();
    }
  }
  log_trace(jfr)("Measured CPU usage for %d threads in %.3f milliseconds", jtiwh.length(),
    (double)(JfrTicks::now() - event_time).milliseconds());
  // Restore this thread's thread id
  periodic_thread_tl->set_thread_id(periodic_thread_id);
}

void JfrThreadCPULoadEvent::send_event_for_thread(JavaThread* jt) {
  EventThreadCPULoad event;
  if (event.should_commit()) {
    if (update_event(event, jt, get_wallclock_time(), get_processor_count())) {
      event.commit();
    }
  }
}

src/hotspot/share/jfr/periodic/jfrThreadCPULoadEvent.hpp:

#ifndef SHARE_VM_JFR_PERIODIC_JFRTHREADCPULOAD_HPP
#define SHARE_VM_JFR_PERIODIC_JFRTHREADCPULOAD_HPP

#include "jni.h"
#include "memory/allocation.hpp"

class JavaThread;
class EventThreadCPULoad;

class JfrThreadCPULoadEvent : public AllStatic {
  static int _last_active_processor_count;
 public:
  static jlong get_wallclock_time();
  static int get_processor_count();
  static bool update_event(EventThreadCPULoad& event, JavaThread* thread, jlong cur_wallclock_time, int processor_count);
  static void send_events();
  static void send_event_for_thread(JavaThread* jt);
};

#endif // SHARE_VM_JFR_PERIODIC_JFRTHREADCPULOAD_HPP

Configuration enabled period
default true 10 s
profiling true 10 s

Field Type Description
user float: percentage User Mode CPU Load User mode thread CPU load
system float: percentage System Mode CPU Load System mode thread CPU load

Examples 3
startTime long: millis
242262176708
system float: percentage
6.9872907E-4
user float: percentage
0.076000534
startTime long: millis
260702629333
system float: percentage
8.457888E-6
user float: percentage
1.0278132E-5
startTime long: millis
217982923125
system float: percentage
1.5323528E-6
user float: percentage
7.960968E-6

ThreadContextSwitchRate

default profiling startTime duration every chunk 11 17 21 25 26

Category: Operating System / Processor

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/jfr/periodic/jfrPeriodic.cpp:

TRACE_REQUEST_FUNC(ThreadContextSwitchRate) {
  double rate = 0.0;
  int ret_val = JfrOSInterface::context_switch_rate(&rate);
  if (ret_val == OS_ERR) {
    log_debug(jfr, system)( "Unable to generate requestable event ThreadContextSwitchRate");
    return;
  }
  if (ret_val == FUNCTIONALITY_NOT_IMPLEMENTED) {
    return;
  }
  if (ret_val == OS_OK) {
    EventThreadContextSwitchRate event;
    event.set_switchRate((float)rate + 0.0f);
    event.commit();
  }
}

#define SEND_FLAGS_OF_TYPE(eventType, flagType)                   \
  do {                                                            \
    JVMFlag *flag = JVMFlag::flags;                               \
    while (flag->_name != NULL) {                                 \
      if (flag->is_ ## flagType()) {                              \
        if (flag->is_unlocked()) {                                \

Configuration enabled period
default true 10 s
profiling true 10 s

Field Type Description
switchRate float: hertz Switch Rate Number of context switches per second

Examples 3
startTime long: millis
265835528458
switchRate float: hertz
20113.96
startTime long: millis
280489579667
switchRate float: hertz
50959.26
startTime long: millis
245620402041
switchRate float: hertz
19986.436

NetworkUtilization

default profiling startTime every chunk 11 17 21 25 26

Category: Operating System / Network

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/jfr/periodic/jfrNetworkUtilization.cpp:

  static JfrTicks last_sample_instant;
  const JfrTicks cur_time = JfrTicks::now();
  const JfrTickspan interval = last_sample_instant == 0 ? cur_time - cur_time : cur_time - last_sample_instant;
  last_sample_instant = cur_time;
  for (NetworkInterface *cur = network_interfaces; cur != NULL; cur = cur->next()) {
    InterfaceEntry& entry = get_entry(cur);
    if (interval.value() > 0) {
      const uint64_t current_bytes_in = cur->get_bytes_in();
      const uint64_t current_bytes_out = cur->get_bytes_out();
      const uint64_t read_rate = rate_per_second(current_bytes_in, entry.bytes_in, interval);
      const uint64_t write_rate = rate_per_second(current_bytes_out, entry.bytes_out, interval);
      if (read_rate > 0 || write_rate > 0) {
        entry.in_use = true;
        EventNetworkUtilization event(UNTIMED);
        event.set_starttime(cur_time);
        event.set_endtime(cur_time);
        event.set_networkInterface(entry.id);
        event.set_readRate(8 * read_rate);
        event.set_writeRate(8 * write_rate);
        event.commit();
      }
      // update existing entry with new values
      entry.bytes_in = current_bytes_in;
      entry.bytes_out = current_bytes_out;
    }

Configuration enabled period
default true 5 s
profiling true 5 s

Field Type Description
networkInterface NetworkInterfaceName Network Interface Network Interface Name
readRate long: bits-per-second Read Rate Number of incoming bits per second
writeRate long: bits-per-second Write Rate Number of outgoing bits per second

Examples 3
networkInterface NetworkInterfaceName
en0
readRate long: bits-per-second
0
startTime long: millis
234646008083
writeRate long: bits-per-second
882400
networkInterface NetworkInterfaceName
lo0
readRate long: bits-per-second
1472
startTime long: millis
286046258542
writeRate long: bits-per-second
1472
networkInterface NetworkInterfaceName
en0
readRate long: bits-per-second
0
startTime long: millis
260779195625
writeRate long: bits-per-second
9216

PhysicalMemory

default profiling startTime duration every chunk 11 17 21 25 26

Category: Operating System / Memory

OS Physical Memory

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/jfr/periodic/jfrPeriodic.cpp:

 *  PhysicalMemory event represents:
 *
 *  @totalSize == The amount of physical memory (hw) installed and reported by the OS, in bytes.
 *  @usedSize  == The amount of physical memory currently in use in the system (reserved/committed), in bytes.
 *
 *  Both fields are systemwide, i.e. represents the entire OS/HW environment.
 *  These fields do not include virtual memory.
 *
 *  If running inside a guest OS on top of a hypervisor in a virtualized environment,
 *  the total memory reported is the amount of memory configured for the guest OS by the hypervisor.
 */
TRACE_REQUEST_FUNC(PhysicalMemory) {
  u8 totalPhysicalMemory = os::physical_memory();
  EventPhysicalMemory event;
  event.set_totalSize(totalPhysicalMemory);
  event.set_usedSize(totalPhysicalMemory - os::available_memory());
  event.commit();
}

TRACE_REQUEST_FUNC(JavaThreadStatistics) {
  EventJavaThreadStatistics event;
  event.set_activeCount(ThreadService::get_live_thread_count());
  event.set_daemonCount(ThreadService::get_daemon_thread_count());
  event.set_accumulatedCount(ThreadService::get_total_thread_count());
  event.set_peakCount(ThreadService::get_peak_thread_count());

Configuration enabled period
default true everyChunk
profiling true everyChunk

Field Type Description
totalSize ulong: bytes Total Size Total amount of physical memory available to OS
usedSize ulong: bytes Used Size Total amount of physical memory in use

Examples 3
startTime long: millis
233805321333
totalSize ulong: bytes
51539607552
usedSize ulong: bytes
48257548288
startTime long: millis
273065656708
totalSize ulong: bytes
51539607552
usedSize ulong: bytes
49033265152
startTime long: millis
242749015583
totalSize ulong: bytes
51539607552
usedSize ulong: bytes
50128502784

Types

CalleeMethod

No description available. Write your own and contribute it to jfreventcollector. or directly to the OpenJDK.

Field Type Description
type string Class
name string Method Name
descriptor string Method Descriptor

Examples 3
descriptor string
(Ljava/lang/invoke/MethodHandle;Ljava/lang/invoke/MethodType;)Ljava/lang/invoke/MethodHandle;
name string
checkGenericType
type string
java/lang/invoke/Invokers
descriptor string
(Lscala/collection/mutable/HashSet;)V
name string
<init>
type string
org/apache/spark/rdd/RDD$$Lambda+0x0000007006390ee8
descriptor string
(Lorg/apache/spark/storage/DiskBlockObjectWriter;)V
name string
<init>
type string
org/apache/spark/storage/DiskBlockObjectWriter$$Lambda+0x0000007006616000

Class

Java Class

Field Type Description
classLoader ClassLoader Class Loader Consider contributing a description to jfreventcollector.
name Symbol Name Consider contributing a description to jfreventcollector.
package Package Package Consider contributing a description to jfreventcollector.
modifiers int Access Modifiers

ClassLoader

Java Class Loader

Field Type Description
type Class Type Consider contributing a description to jfreventcollector.
name Symbol Name Consider contributing a description to jfreventcollector.

CodeBlobType

Code Blob Type No description available. Write your own and contribute it to jfreventcollector. or directly to the OpenJDK.

Field Type Description
type string Type

Examples 3
CodeHeap 'profiled nmethods'
CodeHeap 'profiled nmethods'
CodeHeap 'non-profiled nmethods'

CompilerPhaseType

Compiler Phase Type No description available. Write your own and contribute it to jfreventcollector. or directly to the OpenJDK.

Field Type Description
phase string Phase

CopyFailed

No description available. Write your own and contribute it to jfreventcollector. or directly to the OpenJDK.

Field Type Description
objectCount ulong Object Count
firstSize ulong: bytes First Failed Object Size
smallestSize ulong: bytes Smallest Failed Object Size
totalSize ulong: bytes Total Object Size

FlagValueOrigin

Flag Value Origin No description available. Write your own and contribute it to jfreventcollector. or directly to the OpenJDK.

Field Type Description
origin string Origin

Examples 3
Default
Default
Ergonomic

FrameType

Frame type No description available. Write your own and contribute it to jfreventcollector. or directly to the OpenJDK.

Field Type Description
description string Description

Examples 3
JIT compiled
JIT compiled
Interpreted

G1EvacuationStatistics

Appearing in: G1GC

Missing in: ParallelGC, SerialGC, ShenandoahGC, ZGC

No description available. Write your own and contribute it to jfreventcollector. or directly to the OpenJDK.

Field Type Description
gcId uint GC Identifier
allocated ulong: bytes Allocated Total memory allocated by PLABs
wasted ulong: bytes Wasted Total memory wasted within PLABs due to alignment or refill
used ulong: bytes Used Total memory occupied by objects within PLABs
undoWaste ulong: bytes Undo Wasted Total memory wasted due to allocation undo within PLABs
regionEndWaste ulong: bytes Region End Wasted Total memory wasted at the end of regions due to refill
regionsRefilled uint: bytes Region Refills Total memory wasted at the end of regions due to refill
directAllocated ulong: bytes Allocated (direct) Total memory allocated using direct allocation outside of PLABs
failureUsed ulong: bytes Used (failure) Total memory occupied by objects in regions where evacuation failed
failureWaste ulong: bytes Wasted (failure) Total memory left unused in regions where evacuation failed

Examples 2
allocated ulong: bytes
6371328
directAllocated ulong: bytes
613344
failureUsed ulong: bytes
0
failureWaste ulong: bytes
0
gcId uint
878
regionEndWaste ulong: bytes
0
regionsRefilled uint: bytes
1
undoWaste ulong: bytes
0
used ulong: bytes
5977712
wasted ulong: bytes
11632
allocated ulong: bytes
0
directAllocated ulong: bytes
0
failureUsed ulong: bytes
0
failureWaste ulong: bytes
0
gcId uint
842
regionEndWaste ulong: bytes
0
regionsRefilled uint: bytes
0
undoWaste ulong: bytes
0
used ulong: bytes
0
wasted ulong: bytes
0

G1HeapRegionType

Appearing in: G1GC

Missing in: ParallelGC, SerialGC, ShenandoahGC, ZGC

G1 Heap Region Type No description available. Write your own and contribute it to jfreventcollector. or directly to the OpenJDK.

Field Type Description
type string Type

Examples 1
Free

G1YCType

Appearing in: G1GC

Missing in: ParallelGC, SerialGC, ShenandoahGC, ZGC

G1 YC Type No description available. Write your own and contribute it to jfreventcollector. or directly to the OpenJDK.

Field Type Description
type string Type

Examples 1
Mixed

GCCause

GC Cause No description available. Write your own and contribute it to jfreventcollector. or directly to the OpenJDK.

Field Type Description
cause string Cause

Examples 3
Heap Inspection Initiated GC
System.gc()
Allocation Failure

GCName

GC Name No description available. Write your own and contribute it to jfreventcollector. or directly to the OpenJDK.

Field Type Description
name string Name

Examples 3
G1New
G1Full
G1Old

GCThresholdUpdater

GC Threshold Updater No description available. Write your own and contribute it to jfreventcollector. or directly to the OpenJDK.

Field Type Description
updater string Updater

Examples 3
compute_new_size
compute_new_size
compute_new_size

GCWhen

GC When No description available. Write your own and contribute it to jfreventcollector. or directly to the OpenJDK.

Field Type Description
when string When

Examples 3
After GC
Before GC
After GC

InflateCause

Inflation Cause No description available. Write your own and contribute it to jfreventcollector. or directly to the OpenJDK.

Field Type Description
cause string Cause

MetadataType

Metadata Type No description available. Write your own and contribute it to jfreventcollector. or directly to the OpenJDK.

Field Type Description
type string Type

Examples 3
Class
Class
Metadata

MetaspaceObjectType

Metaspace Object Type No description available. Write your own and contribute it to jfreventcollector. or directly to the OpenJDK.

Field Type Description
type string Type

MetaspaceSizes

No description available. Write your own and contribute it to jfreventcollector. or directly to the OpenJDK.

Field Type Description
committed ulong: bytes Committed Committed memory for this space
used ulong: bytes Used Bytes allocated by objects in the space
reserved ulong: bytes Reserved Reserved memory for this space

Examples 3
committed ulong: bytes
665255936
reserved ulong: bytes
1677721600
used ulong: bytes
661369672
committed ulong: bytes
574095360
reserved ulong: bytes
603979776
used ulong: bytes
572158760
committed ulong: bytes
91160576
reserved ulong: bytes
1073741824
used ulong: bytes
89210912

Method

Java Method

Field Type Description
type Class Type Consider contributing a description to jfreventcollector.
name Symbol Name Consider contributing a description to jfreventcollector.
descriptor Symbol Descriptor Consider contributing a description to jfreventcollector.
modifiers int Access Modifiers
hidden boolean Hidden

Module

Module No description available. Write your own and contribute it to jfreventcollector. or directly to the OpenJDK.

Field Type Description
name Symbol Name Consider contributing a description to jfreventcollector.
version Symbol Version Consider contributing a description to jfreventcollector.
location Symbol Location Consider contributing a description to jfreventcollector.
classLoader ClassLoader Class Loader Consider contributing a description to jfreventcollector.

NarrowOopMode

Narrow Oop Mode No description available. Write your own and contribute it to jfreventcollector. or directly to the OpenJDK.

Field Type Description
mode string Mode

Examples 3
Zero based
Zero based
Zero based

NetworkInterfaceName

Network Interface No description available. Write your own and contribute it to jfreventcollector. or directly to the OpenJDK.

Field Type Description
networkInterface string Network Interface Network Interface Name

Examples 3
en0
lo0
en0

ObjectSpace

Appearing in: ParallelGC

Missing in: G1GC, SerialGC, ShenandoahGC, ZGC

No description available. Write your own and contribute it to jfreventcollector. or directly to the OpenJDK.

Field Type Description
start ulong: address Start Address Start address of the space
end ulong: address End Address End address of the space
used ulong: bytes Used Bytes allocated by objects in the space
size ulong: bytes Size Size of the space

Examples 3
end ulong: address
23519035392
size ulong: bytes
2044198912
start ulong: address
21474836480
used ulong: bytes
372660984
end ulong: address
33555480576
size ulong: bytes
1048576
start ulong: address
33554432000
used ulong: bytes
946384
end ulong: address
33392951296
size ulong: bytes
3328180224
start ulong: address
30064771072
used ulong: bytes
0

OldObject

Old Object No description available. Write your own and contribute it to jfreventcollector. or directly to the OpenJDK.

Field Type Description
address ulong: address Memory Address
type Class Java Class
description string Object Description Object description
referrer Reference Referrer Object Object referencing this object

Examples 3
address ulong: address
21771390872
description string
null
referrer Reference
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1041
name string
[Ljava/util/concurrent/ForkJoinTask;
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/util/concurrent
address ulong: address
21520598200
description string
Class Name: com.twitter.chill.java.Java8ClosureRegistrar
referrer Reference
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
17
name string
java/lang/Class
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/lang
address ulong: address
25969620872
description string
null
referrer Reference
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
17
name string
java/lang/invoke/MethodType
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/lang/invoke

OldObjectArray

Old Object Array No description available. Write your own and contribute it to jfreventcollector. or directly to the OpenJDK.

Field Type Description
size int Array Size Size of array
index int Index Index in the array

OldObjectField

Old Object Field No description available. Write your own and contribute it to jfreventcollector. or directly to the OpenJDK.

Field Type Description
name string Field Name of field
modifiers short Field Modifiers Field modifiers

OldObjectGcRoot

GC Root No description available. Write your own and contribute it to jfreventcollector. or directly to the OpenJDK.

Field Type Description
description string Root Description Root information
system OldObjectRootSystem System The subsystem of origin for the root
type OldObjectRootType Type The root type

Examples 3
null
null
null

OldObjectRootSystem

GC Root System No description available. Write your own and contribute it to jfreventcollector. or directly to the OpenJDK.

Field Type Description
system string System

OldObjectRootType

GC Root Type No description available. Write your own and contribute it to jfreventcollector. or directly to the OpenJDK.

Field Type Description
type string Type

Package

Package No description available. Write your own and contribute it to jfreventcollector. or directly to the OpenJDK.

Field Type Description
name Symbol Name Consider contributing a description to jfreventcollector.
module Module Module Consider contributing a description to jfreventcollector.
exported boolean Exported

Reference

Reference No description available. Write your own and contribute it to jfreventcollector. or directly to the OpenJDK.

Field Type Description
array OldObjectArray Array Information Array or null if it is not an array
field OldObjectField Field Information Field or null if it is an array
object OldObject Object Object holder for this reference
skip int Skip Value The object is this many hops away

Examples 3
null
null
null

ReferenceType

Reference Type No description available. Write your own and contribute it to jfreventcollector. or directly to the OpenJDK.

Field Type Description
type string Type

Examples 3
Final reference
Soft reference
Phantom reference

StackFrame

No description available. Write your own and contribute it to jfreventcollector. or directly to the OpenJDK.

Field Type Description
method Method Java Method
lineNumber int Line Number
bytecodeIndex int Bytecode Index
type FrameType Frame Type

Examples 3
bytecodeIndex int
34
lineNumber int
89
method Method
descriptor string
(Ljava/lang/String;Ljava/lang/String;)V
hidden boolean
false
modifiers int
1
name string
put
type Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/net
hidden boolean
false
modifiers int
1
name string
org/apache/logging/log4j/spi/DefaultThreadContextMap
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/net
location string
null
name string
null
version string
null
name string
org/apache/logging/log4j/spi
type FrameType
Interpreted
bytecodeIndex int
62
lineNumber int
375
method Method
descriptor string
(Ljava/lang/String;Ljava/lang/Throwable;ZZ)V
hidden boolean
false
modifiers int
4
name string
<init>
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/lang/Throwable
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/lang
type FrameType
JIT compiled
bytecodeIndex int
31
lineNumber int
102
method Method
descriptor string
(Ljava/io/OutputStream;ILnet/jpountz/lz4/LZ4Compressor;Ljava/util/zip/Checksum;Z)V
hidden boolean
false
modifiers int
1
name string
<init>
type Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/net
hidden boolean
false
modifiers int
1
name string
net/jpountz/lz4/LZ4BlockOutputStream
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/net
location string
null
name string
null
version string
null
name string
net/jpountz/lz4
type FrameType
JIT compiled

StackTrace

Stacktrace No description available. Write your own and contribute it to jfreventcollector. or directly to the OpenJDK.

Field Type Description
truncated boolean Truncated
frames array StackFrame struct Stack Frames

Examples 3
frames StackFrame
bytecodeIndex int
62
lineNumber int
375
method Method
descriptor string
(Ljava/lang/String;Ljava/lang/Throwable;ZZ)V
hidden boolean
false
modifiers int
4
name string
<init>
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/lang/Throwable
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/lang
type FrameType
JIT compiled
truncated boolean
false
null
frames StackFrame
bytecodeIndex int
62
lineNumber int
375
method Method
descriptor string
(Ljava/lang/String;Ljava/lang/Throwable;ZZ)V
hidden boolean
false
modifiers int
4
name string
<init>
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/lang/Throwable
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/lang
type FrameType
JIT compiled
truncated boolean
false

Symbol

Symbol No description available. Write your own and contribute it to jfreventcollector. or directly to the OpenJDK.

Field Type Description
string string String

Thread

Thread No description available. Write your own and contribute it to jfreventcollector. or directly to the OpenJDK.

Field Type Description
osName string OS Thread Name
osThreadId long OS Thread Id
javaName string Java Thread Name
javaThreadId long Java Thread Id
group ThreadGroup Java Thread Group

ThreadGroup

Thread Group No description available. Write your own and contribute it to jfreventcollector. or directly to the OpenJDK.

Field Type Description
parent ThreadGroup Parent Consider contributing a description to jfreventcollector.
name string Name

Examples 3
null
name string
system
parent ThreadGroup
null
name string
main
parent ThreadGroup
name string
system
parent ThreadGroup
null

ThreadState

Java Thread State

Field Type Description
name string Name

Examples 3
STATE_RUNNABLE
STATE_RUNNABLE
STATE_RUNNABLE

VMOperationType

VM Operation Type No description available. Write your own and contribute it to jfreventcollector. or directly to the OpenJDK.

Field Type Description
type string Type

Examples 3
ClassLoaderStatsOperation
HandshakeAllThreads
GenCollectFull

VirtualSpace

No description available. Write your own and contribute it to jfreventcollector. or directly to the OpenJDK.

Field Type Description
start ulong: address Start Address Start address of the virtual space
committedEnd ulong: address Committed End Address End address of the committed memory for the virtual space
committedSize ulong: bytes Committed Size Size of the committed memory for the virtual space
reservedEnd ulong: address Reserved End Address End address of the reserved memory for the virtual space
reservedSize ulong: bytes Reserved Size Size of the reserved memory for the virtual space

Examples 3
committedEnd ulong: address
24847056896
committedSize ulong: bytes
3372220416
reservedEnd ulong: address
34359738368
reservedSize ulong: bytes
12884901888
start ulong: address
21474836480
committedEnd ulong: address
26848264192
committedSize ulong: bytes
5373427712
reservedEnd ulong: address
34359738368
reservedSize ulong: bytes
12884901888
start ulong: address
21474836480
committedEnd ulong: address
23519035392
committedSize ulong: bytes
2044198912
reservedEnd ulong: address
30064771072
reservedSize ulong: bytes
8589934592
start ulong: address
21474836480

ZStatisticsCounterType

Appearing in: ZGC

Missing in: G1GC, ParallelGC, SerialGC, ShenandoahGC

Z Statistics Counter No description available. Write your own and contribute it to jfreventcollector. or directly to the OpenJDK.

Field Type Description
counter string Counter

Examples 1
Allocation Rate

ZStatisticsSamplerType

Appearing in: ZGC

Missing in: G1GC, ParallelGC, SerialGC, ShenandoahGC

Z Statistics Sampler No description available. Write your own and contribute it to jfreventcollector. or directly to the OpenJDK.

Field Type Description
sampler string Sampler

Examples 1
Undo Page Allocation

XML Content Types

address

Annotation: jdk.jfr.MemoryAddress

Examples 3
34359738368
24847056896
21474836480

bits-per-second

Annotation: jdk.jfr.DataAmount(BITS), jdk.jfr.Frequency

Examples 3
882400
0
0

bytes

Annotation: jdk.jfr.DataAmount(BYTES)

Examples 3
48
262144000
4194304

bytes-per-second

Appearing in: G1GC

Missing in: ParallelGC, SerialGC, ShenandoahGC, ZGC

Annotation: jdk.jfr.DataAmount(BYTES), jdk.jfr.Frequency

Examples 2
0.0
2.945689613301255E9

certificateId

Annotation: jdk.jfr.events.CertificateId

Examples 3
3045411335
3045411335
3045411335

epochmillis

Annotation: jdk.jfr.Timestamp(MILLISECONDS_SINCE_EPOCH)

Examples 3
1754910293748
1754910293523
-9223372036854775808

hertz

Annotation: jdk.jfr.Frequency

Examples 3
1000000000
19986.436
1000000000

millis

Annotation: jdk.jfr.Timespan(MILLISECONDS)

Examples 3
198990064916
9223372036854775807
199115266000

nanos

Annotation: jdk.jfr.Timespan(NANOSECONDS)

Examples 3
-9223372036854775808
-9223372036854775808
-9223372036854775808

percentage

Annotation: jdk.jfr.Percentage

Examples 3
0.15530303
0.0
0.27150953

tickspan

Annotation: jdk.jfr.Timespan(TICKS)

Examples 3
2839458
34701875
56905792

tickstamp

Annotation: jdk.jfr.Timestamp(TICKS)

XML Types

Class

No description available. Write your own and contribute it to jfreventcollector. or directly to the OpenJDK.

Parameter Type const Klass*
Field Type const Klass*
Java Type java.lang.Class
Examples 3
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/net
null
null

ClassLoader

No description available. Write your own and contribute it to jfreventcollector. or directly to the OpenJDK.

Parameter Type const ClassLoaderData*
Field Type const ClassLoaderData*
Examples 3
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/net
name string
bootstrap
type Class
null
name string
bootstrap
type Class
null

Method

No description available. Write your own and contribute it to jfreventcollector. or directly to the OpenJDK.

Parameter Type const Method*
Field Type const Method*
Examples 3
descriptor string
(Ljava/lang/Object;Ljava/lang/Object;)Ljava/lang/Object;
hidden boolean
true
modifiers int
8
name string
newInvokeSpecial
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
16
name string
java/lang/invoke/DirectMethodHandle$Holder
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/lang/invoke
descriptor string
(Ljava/lang/String;Ljava/lang/String;)V
hidden boolean
false
modifiers int
1
name string
put
type Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/net
hidden boolean
false
modifiers int
1
name string
org/apache/logging/log4j/spi/DefaultThreadContextMap
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/net
location string
null
name string
null
version string
null
name string
org/apache/logging/log4j/spi
descriptor string
(Ljava/lang/String;Ljava/lang/Throwable;ZZ)V
hidden boolean
false
modifiers int
4
name string
<init>
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/lang/Throwable
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/lang

Module

No description available. Write your own and contribute it to jfreventcollector. or directly to the OpenJDK.

Parameter Type const ModuleEntry*
Field Type const ModuleEntry*
Examples 3
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/net
location string
null
name string
null
version string
null
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7

Package

No description available. Write your own and contribute it to jfreventcollector. or directly to the OpenJDK.

Parameter Type const PackageEntry*
Field Type const PackageEntry*
Examples 3
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/net
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/net
location string
null
name string
null
version string
null
name string
scala/runtime
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.7
name string
java/net

Thread

No description available. Write your own and contribute it to jfreventcollector. or directly to the OpenJDK.

Parameter Type u8
Field Type u8
Java Type java.lang.Thread
Examples 3
group ThreadGroup
name string
main
parent ThreadGroup
name string
system
parent ThreadGroup
null
javaName string
block-manager-ask-thread-pool-66
javaThreadId long
1763
osName string
block-manager-ask-thread-pool-66
osThreadId long
247555
virtual boolean
false
group ThreadGroup
name string
main
parent ThreadGroup
name string
system
parent ThreadGroup
null
javaName string
RxComputationThreadPool-5
javaThreadId long
1135
osName string
RxComputationThreadPool-5
osThreadId long
179739
virtual boolean
false
group ThreadGroup
name string
main
parent ThreadGroup
name string
system
parent ThreadGroup
null
javaName string
JFR Periodic Tasks
javaThreadId long
20
osName string
JFR Periodic Tasks
osThreadId long
32771
virtual boolean
false

Ticks

No description available. Write your own and contribute it to jfreventcollector. or directly to the OpenJDK.

Parameter Type const Ticks&
Field Type Ticks
Java Type long
Content Type tickstamp
Examples 3
33406287292
218316691167
249331056208

Tickspan

No description available. Write your own and contribute it to jfreventcollector. or directly to the OpenJDK.

Parameter Type const Tickspan&
Field Type Tickspan
Java Type long
Content Type tickspan

boolean

Parameter Type bool
Field Type bool
Java Type boolean
Examples 3
true
true
false

byte

Parameter Type s1
Field Type s1
Java Type byte

char

Parameter Type char
Field Type char
Java Type char

double

Parameter Type double
Field Type double
Java Type double
Examples 3
1.0
2.0
50.0

float

Parameter Type float
Field Type float
Java Type float

int

Parameter Type s4
Field Type s4
Java Type int
Examples 3
1
1
1

long

Parameter Type s8
Field Type s8
Java Type long
Examples 3
1
96009
24

short

Parameter Type s2
Field Type s2
Java Type short

string

Parameter Type const char*
Field Type const char*
Java Type java.lang.String
Examples 3
java/net/URLClassLoader
bootstrap
null

ubyte

unsigned

Parameter Type u1
Field Type u1
Java Type byte
Examples 3
15
32
7

uint

unsigned

Parameter Type unsigned
Field Type unsigned
Java Type int
Examples 3
82514
788
791

ulong

unsigned

Parameter Type u8
Field Type u8
Java Type long
Examples 3
1778
1783
1739

ushort

unsigned

Parameter Type u2
Field Type u2
Java Type short
Examples 3
3
4
4