Introduction

The following are the events for OpenJDK 13 (jdk-13.0.14+5, permalink, 15-March-2026). 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 27

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 27

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

ActiveSetting

default profiling startTime duration stackTrace 11 17 21 25 26 27

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

Category: Flight Recorder

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/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();
    }

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/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;
}

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
57
name string
enabled
stackTrace StackTrace
null
startTime long: millis
358733835312
value string
true
id long
7
name string
period
stackTrace StackTrace
null
startTime long: millis
378261016404
value string
1000 ms
id long
53
name string
enabled
stackTrace StackTrace
null
startTime long: millis
300583922501
value string
true

ActiveRecording

default profiling startTime duration stackTrace 11 17 21 25 26 27

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

Category: Flight Recorder

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/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.getRealPathText();
                    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,

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")

Configuration enabled
default true
profiling true

Field Type Description
id long Id
name string Name
destination string Destination
maxAge long: millis Max Age
maxSize long: bytes Max Size
recordingStart long: epochmillis Start Time
recordingDuration long: millis Recording Duration

Examples 3
destination string
/home/runner/work/jfrevents/jfrevents/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
1773535704154
stackTrace StackTrace
null
startTime long: millis
466042001646
destination string
/home/runner/work/jfrevents/jfrevents/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
1773535704061
stackTrace StackTrace
null
startTime long: millis
479836096691
destination string
/home/runner/work/jfrevents/jfrevents/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
1773535714974
stackTrace StackTrace
null
startTime long: millis
310516944914

JVM

JVMInformation

default profiling startTime duration end of every chunk 11 17 21 25 26 27

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:

#if INCLUDE_SHENANDOAHGC
#include "gc/shenandoah/shenandoahJfrSupport.hpp"
#endif
/**
 *  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
/home/runner/work/jfrevents/jfrevents/.cache/renaissance.jar -t 5 -r 1 all
jvmArguments string
-XX:StartFlightRecording=filename=/home/runner/work/jfrevents/jfrevents/jfr/sample_UseParallelGC.jfr,settings=/home/runner/work/jfrevents/jfrevents/.cache/jfc.jfc -XX:+UseParallelGC
jvmFlags string
null
jvmName string
OpenJDK 64-Bit Server VM
jvmStartTime long: epochmillis
1773535703645
jvmVersion string
OpenJDK 64-Bit Server VM (21.0.10.0.1+1-LTS) for linux-amd64 JRE (21.0.10.0.1+1-LTS), built on 2026-02-17T05:46:25Z by "jenkinsi" with gcc 11.3.0
pid long
2400
startTime long: millis
384843595329
javaArguments string
/home/runner/work/jfrevents/jfrevents/.cache/renaissance.jar -t 5 -r 1 all
jvmArguments string
-XX:StartFlightRecording=filename=/home/runner/work/jfrevents/jfrevents/jfr/sample_UseSerialGC.jfr,settings=/home/runner/work/jfrevents/jfrevents/.cache/jfc.jfc -XX:+UseSerialGC
jvmFlags string
null
jvmName string
OpenJDK 64-Bit Server VM
jvmStartTime long: epochmillis
1773535703720
jvmVersion string
OpenJDK 64-Bit Server VM (21.0.10.0.1+1-LTS) for linux-amd64 JRE (21.0.10.0.1+1-LTS), built on 2026-02-17T05:46:25Z by "jenkinsi" with gcc 11.3.0
pid long
2422
startTime long: millis
383952212845
javaArguments string
/home/runner/work/jfrevents/jfrevents/.cache/renaissance.jar -t 5 -r 1 all
jvmArguments string
-XX:StartFlightRecording=filename=/home/runner/work/jfrevents/jfrevents/jfr/sample_UseG1GC.jfr,settings=/home/runner/work/jfrevents/jfrevents/.cache/jfc.jfc -XX:+UseG1GC
jvmFlags string
null
jvmName string
OpenJDK 64-Bit Server VM
jvmStartTime long: epochmillis
1773535714518
jvmVersion string
OpenJDK 64-Bit Server VM (21.0.10.0.1+1-LTS) for linux-amd64 JRE (21.0.10.0.1+1-LTS), built on 2026-02-17T05:46:25Z by "jenkinsi" with gcc 11.3.0
pid long
2392
startTime long: millis
305232669226

InitialSystemProperty

default profiling startTime end of every chunk 11 17 21 25 26 27

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
sun.java.command
startTime long: millis
358740856279
value string
/home/runner/work/jfrevents/jfrevents/.cache/renaissance.jar -t 5 -r 1 all
key string
sun.java.launcher
startTime long: millis
313275806799
value string
SUN_STANDARD
key string
java.vm.name
startTime long: millis
400209868631
value string
OpenJDK 64-Bit Server VM

JVM: Class Loading

ClassLoad

startTime duration eventThread stackTrace 11 17 21 25 26 27

Category: Java Virtual Machine / Class Loading

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
definingClassLoader ClassLoader Defining Class Loader
initiatingClassLoader ClassLoader Initiating Class Loader

Examples 3
definingClassLoader ClassLoader
null
initiatingClassLoader ClassLoader
null
loadedClass Class
classLoader ClassLoader
null
hidden boolean
true
modifiers int
16
name string
java.lang.invoke.LambdaForm$MH/0x00007f6319436400
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.10.0.1
name string
java/lang/invoke
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
0
lineNumber int
-1
method Method
descriptor string
(Ljava/lang/ClassLoader;Ljava/lang/Class;Ljava/lang/String;[BIILjava/security/ProtectionDomain;ZILjava/lang/Object;)Ljava/lang/Class;
hidden boolean
false
modifiers int
264
name string
defineClass0
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1025
name string
java/lang/ClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.10.0.1
name string
java/lang
type FrameType
Native
truncated boolean
true
startTime long: millis
380746297655
definingClassLoader ClassLoader
null
initiatingClassLoader ClassLoader
null
loadedClass Class
classLoader ClassLoader
null
hidden boolean
true
modifiers int
16
name string
java.lang.invoke.LambdaForm$DMH/0x00007fc8a541d000
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
21.0.10.0.1
name string
java/lang/invoke
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
0
lineNumber int
-1
method Method
descriptor string
(Ljava/lang/ClassLoader;Ljava/lang/Class;Ljava/lang/String;[BIILjava/security/ProtectionDomain;ZILjava/lang/Object;)Ljava/lang/Class;
hidden boolean
false
modifiers int
264
name string
defineClass0
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
21.0.10.0.1
name string
java/lang
type FrameType
Native
truncated boolean
true
startTime long: millis
372195811861
definingClassLoader ClassLoader
null
initiatingClassLoader ClassLoader
null
loadedClass Class
classLoader ClassLoader
null
hidden boolean
true
modifiers int
16
name string
java.lang.invoke.LambdaForm$MH/0x00007efd893fbc00
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
21.0.10.0.1
name string
java/lang/invoke
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
0
lineNumber int
-1
method Method
descriptor string
(Ljava/lang/ClassLoader;Ljava/lang/Class;Ljava/lang/String;[BIILjava/security/ProtectionDomain;ZILjava/lang/Object;)Ljava/lang/Class;
hidden boolean
false
modifiers int
264
name string
defineClass0
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
21.0.10.0.1
name string
java/lang
type FrameType
Native
truncated boolean
false
startTime long: millis
301140290601

ClassDefine

startTime eventThread stackTrace 11 17 21 25 26 27

Category: Java Virtual Machine / Class Loading

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
definingClassLoader ClassLoader Defining Class Loader

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
21.0.10.0.1
name string
java/net
hidden boolean
false
modifiers int
1537
name string
scala/reflect/internal/util/Collections
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
21.0.10.0.1
name string
java/net
location string
null
name string
null
version string
null
name string
scala/reflect/internal/util
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
21.0.10.0.1
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
21.0.10.0.1
name string
java/lang
type FrameType
Native
truncated boolean
true
startTime long: millis
441442141117
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
21.0.10.0.1
name string
java/net
hidden boolean
false
modifiers int
1537
name string
scala/reflect/internal/AnnotationInfos
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
21.0.10.0.1
name string
java/net
location string
null
name string
null
version string
null
name string
scala/reflect/internal
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
21.0.10.0.1
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
21.0.10.0.1
name string
java/lang
type FrameType
Native
truncated boolean
false
startTime long: millis
418538958798
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
21.0.10.0.1
name string
java/net
hidden boolean
false
modifiers int
17
name string
org/apache/spark/sql/SQLImplicits$$typecreator1$7
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
21.0.10.0.1
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
21.0.10.0.1
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
21.0.10.0.1
name string
java/lang
type FrameType
Native
truncated boolean
false
startTime long: millis
327151809671

ClassUnload

startTime eventThread 11 17 21 25 26 27

Category: Java Virtual Machine / Class Loading

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:

  if (DumpSharedSpaces || DynamicDumpSharedSpaces) {
    SystemDictionaryShared::remove_dumptime_info(ik);
  }

  if (log_is_enabled(Info, class, unload)) {
    ResourceMark rm;
    log_info(class, unload)("unloading class %s " INTPTR_FORMAT, ik->external_name(), p2i(ik));
  }

  Events::log_class_unloading(Thread::current(), 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
definingClassLoader ClassLoader Defining Class Loader

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
21.0.10.0.1
name string
java/net
startTime long: millis
430219459941
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
21.0.10.0.1
name string
java/net
hidden boolean
true
modifiers int
4112
name string
org.renaissance.jdk.streams.MnemonicsCoderWithStream$$Lambda/0x00007fc8a55c6ff8
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.10.0.1
name string
java/net
location string
null
name string
null
version string
null
name string
org/renaissance/jdk/streams
definingClassLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.10.0.1
name string
java/net
startTime long: millis
334551320668
unloadedClass Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.10.0.1
name string
java/net
hidden boolean
true
modifiers int
4112
name string
org.renaissance.jdk.streams.MnemonicsCoderWithStream$$Lambda/0x00007efd895b1d70
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
21.0.10.0.1
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
21.0.10.0.1
name string
java/net
startTime long: millis
446257643165
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
21.0.10.0.1
name string
java/net
hidden boolean
false
modifiers int
17
name string
scala/collection/immutable/MapNode$
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
21.0.10.0.1
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 27

Category: Java Virtual Machine / Code Cache

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
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 27

Category: Java Virtual Machine / Code Cache

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
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
2310
codeBlobType CodeBlobType
CodeHeap 'non-nmethods'
entryCount int
2407
fullCount int
0
methodCount int
0
reservedTopAddress ulong: address
140064926236672
startAddress ulong: address
140064920399872
startTime long: millis
384855753106
unallocatedCapacity ulong: bytes
2868352
adaptorCount int
2459
codeBlobType CodeBlobType
CodeHeap 'non-nmethods'
entryCount int
2558
fullCount int
0
methodCount int
0
reservedTopAddress ulong: address
140500865417216
startAddress ulong: address
140500859580416
startTime long: millis
470722232898
unallocatedCapacity ulong: bytes
2737920
adaptorCount int
0
codeBlobType CodeBlobType
CodeHeap 'profiled nmethods'
entryCount int
8235
fullCount int
0
methodCount int
8235
reservedTopAddress ulong: address
139629048328192
startAddress ulong: address
139628925419520
startTime long: millis
351769810494
unallocatedCapacity ulong: bytes
97450496

CodeCacheConfiguration

default profiling startTime end of every chunk 11 17 21 25 26 27

Category: Java Virtual Machine / Code Cache

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
5832780
nonProfiledSize ulong: bytes
122912730
profiledSize ulong: bytes
122912730
reservedSize ulong: bytes
251658240
reservedTopAddress ulong: address
140065049149440
startAddress ulong: address
140064797491200
startTime long: millis
378279249337
expansionSize ulong: bytes
65536
initialSize ulong: bytes
2555904
minBlockLength ulong: bytes
6
nonNMethodSize ulong: bytes
5832780
nonProfiledSize ulong: bytes
122912730
profiledSize ulong: bytes
122912730
reservedSize ulong: bytes
251658240
reservedTopAddress ulong: address
140500988329984
startAddress ulong: address
140500736671744
startTime long: millis
392299900719
expansionSize ulong: bytes
65536
initialSize ulong: bytes
2555904
minBlockLength ulong: bytes
6
nonNMethodSize ulong: bytes
5832780
nonProfiledSize ulong: bytes
122912730
profiledSize ulong: bytes
122912730
reservedSize ulong: bytes
251658240
reservedTopAddress ulong: address
139629177077760
startAddress ulong: address
139628925419520
startTime long: millis
369405386912

JVM: Code Sweeper

SweepCodeCache

default profiling startTime duration eventThread 11 17 until JDK 20

Category: Java Virtual Machine / Code Sweeper

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");
    MutexLocker 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;
  {
    MutexLocker 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

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

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(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();
}


TRACE_REQUEST_FUNC(ShenandoahHeapRegionInformation) {
#if INCLUDE_SHENANDOAHGC
  if (UseShenandoahGC) {
    VM_ShenandoahSendHeapRegionInfoEvents op;
    VMThread::execute(&op);

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 27

Category: Java Virtual Machine / Compiler

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 {
      JVMCICompileState compile_state(task, system_dictionary_modification_counter);
      JVMCIEnv env(thread, &compile_state, __FILE__, __LINE__);
      methodHandle method(thread, target_handle);
      env.runtime()->compile_method(&env, jvmci, method, osr_bci);

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) {
        MonitorLocker locker(Compilation_lock, Mutex::_no_safepoint_check_flag);
        while (WhiteBox::compilation_locked) {
          locker.wait();
        }
      }
      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
768
compileId uint
74620
compileLevel ushort
3
inlinedBytes ulong: bytes
0
isOsr boolean
false
method Method
descriptor string
(Ljava/lang/Object;)Ljava/lang/Object;
hidden boolean
true
modifiers int
1
name string
apply
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
21.0.10.0.1
name string
java/net
hidden boolean
true
modifiers int
4112
name string
org.apache.spark.scheduler.TaskSetManager$$Lambda/0x00007f63191f5a18
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.10.0.1
name string
java/net
location string
null
name string
null
version string
null
name string
org/apache/spark/scheduler
startTime long: millis
439566183392
succeded boolean
true
codeSize ulong: bytes
1184
compileId uint
72968
compileLevel ushort
4
inlinedBytes ulong: bytes
74
isOsr boolean
false
method Method
descriptor string
()Ljava/lang/Object;
hidden boolean
true
modifiers int
1
name string
apply
type Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.10.0.1
name string
java/net
hidden boolean
true
modifiers int
4112
name string
org.apache.spark.rdd.RDD$$Lambda/0x00007fc8a5165358
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
21.0.10.0.1
name string
java/net
location string
null
name string
null
version string
null
name string
org/apache/spark/rdd
startTime long: millis
376732743547
succeded boolean
true
codeSize ulong: bytes
64864
compileId uint
89010
compileLevel ushort
4
inlinedBytes ulong: bytes
16380
isOsr boolean
false
method Method
descriptor string
(Ldotty/tools/dotc/core/Names$Name;Ldotty/tools/dotc/core/Contexts$Context;)Ldotty/tools/dotc/core/Scopes$ScopeEntry;
hidden boolean
false
modifiers int
1
name string
lookupEntry
type Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.10.0.1
name string
java/net
hidden boolean
false
modifiers int
17
name string
dotty/tools/dotc/core/SymbolLoaders$PackageLoader$PackageScope
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
21.0.10.0.1
name string
java/net
location string
null
name string
null
version string
null
name string
dotty/tools/dotc/core
startTime long: millis
361813294104
succeded boolean
true

CompilerPhase

default profiling startTime duration eventThread 11 17 21 25 26 27

Category: Java Virtual Machine / Compiler

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:

    C->_latest_stage_start_counter.stamp();
  }

  bool should_print(int level = 1) {
#ifndef PRODUCT
    return (_printer && _printer->should_print(level));
#else
    return false;
#endif
  }

  void print_method(CompilerPhaseType cpt, int level = 1, int idx = 0) {
    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 (should_print(level)) {
      char output[1024];
      if (idx != 0) {
        sprintf(output, "%s:%d", CompilerPhaseTypeHelper::to_string(cpt), idx);
      } else {
        sprintf(output, "%s", CompilerPhaseTypeHelper::to_string(cpt));
      }
      _printer->print_method(output, 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 27

Category: Java Virtual Machine / Compiler

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
94254
failureMessage string
retry without subsuming loads
startTime long: millis
477679336569
compileId uint
76293
failureMessage string
retry without subsuming loads
startTime long: millis
335549269624
compileId uint
75759
failureMessage string
retry without subsuming loads
startTime long: millis
431564001023

CompilerInlining

startTime eventThread 11 17 21 25 26 27

Category: Java Virtual Machine / Compiler / Optimization

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:

  event->commit();
}

void GraphBuilder::print_inlining(ciMethod* callee, const char* msg, bool success) {
  CompileLog* log = compilation()->log();
  if (log != NULL) {
    assert(msg != NULL, "inlining msg should not be null!");
    if (success) {
      log->inline_success(msg);
    } else {
      log->inline_fail(msg);
    }
  }
  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
9
callee CalleeMethod
descriptor string
(Ljava/lang/Throwable$PrintStreamOrWriter;)V
name string
printStackTrace
type string
java/lang/Throwable
caller Method
descriptor string
(Ljava/io/PrintStream;)V
hidden boolean
false
modifiers int
1
name string
printStackTrace
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
21.0.10.0.1
name string
java/lang
compileId uint
72658
message string
callee is too large
startTime long: millis
358738283964
succeeded boolean
false
bci int
1
callee CalleeMethod
descriptor string
()J
name string
gap
type string
scala/collection/immutable/Range
caller Method
descriptor string
()Z
hidden boolean
false
modifiers int
2
name string
isExact
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
21.0.10.0.1
name string
java/net
hidden boolean
false
modifiers int
1025
name string
scala/collection/immutable/Range
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
21.0.10.0.1
name string
java/net
location string
null
name string
null
version string
null
name string
scala/collection/immutable
compileId uint
73110
message string
inline (hot)
startTime long: millis
300584359537
succeeded boolean
true
bci int
31
callee CalleeMethod
descriptor string
()Ljava/lang/String;
name string
trim
type string
java/lang/String
caller Method
descriptor string
(Ljava/lang/String;)Ljava/lang/Object;
hidden boolean
false
modifiers int
1
name string
get
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
javax/management/openmbean/CompositeDataSupport
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.management
name string
java.management
version string
21.0.10.0.1
name string
javax/management/openmbean
compileId uint
73340
message string
inline (hot)
startTime long: millis
378436149060
succeeded boolean
true

CompilerStatistics

default profiling startTime every chunk 11 17 21 25 26 27

Category: Java Virtual Machine / Compiler

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(LoaderConstraintsTableStatistics) {
  TableStatistics statistics = SystemDictionary::loader_constraints_statistics();
  emit_table_statistics<EventLoaderConstraintsTableStatistics>(statistics);
}

TRACE_REQUEST_FUNC(ProtectionDomainCacheTableStatistics) {
  TableStatistics statistics = SystemDictionary::protection_domain_cache_statistics();
  emit_table_statistics<EventProtectionDomainCacheTableStatistics>(statistics);
}

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_nmethodsSize(CompileBroker::get_sum_nmethod_size());
  event.set_nmethodCodeSize(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
nmethodsSize ulong: bytes Compilation Resulting Size
nmethodCodeSize ulong: bytes Compilation Resulting Code Size
peakTimeSpent long: millis Peak Time
totalTimeSpent long: millis Total time

Examples 3
bailoutCount int
12
compileCount int
72310
invalidatedCount int
0
nmethodCodeSize ulong: bytes
101543016
nmethodsSize ulong: bytes
147589920
osrBytesCompiled ulong: bytes
0
osrCompileCount int
842
peakTimeSpent long: millis
6642
standardBytesCompiled ulong: bytes
0
standardCompileCount int
71468
startTime long: millis
310706179574
totalTimeSpent long: millis
301597
bailoutCount int
13
compileCount int
71867
invalidatedCount int
0
nmethodCodeSize ulong: bytes
95348784
nmethodsSize ulong: bytes
141615824
osrBytesCompiled ulong: bytes
0
osrCompileCount int
839
peakTimeSpent long: millis
8464
standardBytesCompiled ulong: bytes
0
standardCompileCount int
71028
startTime long: millis
401564268483
totalTimeSpent long: millis
514007
bailoutCount int
13
compileCount int
91580
invalidatedCount int
0
nmethodCodeSize ulong: bytes
124647120
nmethodsSize ulong: bytes
182937768
osrBytesCompiled ulong: bytes
0
osrCompileCount int
1004
peakTimeSpent long: millis
11768
standardBytesCompiled ulong: bytes
0
standardCompileCount int
90576
startTime long: millis
476804520381
totalTimeSpent long: millis
846223

CompilerConfiguration

default profiling startTime end of every chunk 11 17 21 25 26 27

Category: Java Virtual Machine / Compiler

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_nmethodsSize(CompileBroker::get_sum_nmethod_size());
  event.set_nmethodCodeSize(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
313294841993
threadCount int
3
tieredCompilation boolean
true
startTime long: millis
483191285567
threadCount int
3
tieredCompilation boolean
true
startTime long: millis
443006522084
threadCount int
3
tieredCompilation boolean
true

JVM: Flag

IntFlagChanged

default profiling startTime 11 17 21 25 26 27

Category: Java Virtual Machine / Flag

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

UnsignedIntFlagChanged

default profiling startTime 11 17 21 25 26 27

Category: Java Virtual Machine / Flag

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

LongFlagChanged

default profiling startTime 11 17 21 25 26 27

Category: Java Virtual Machine / Flag

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

UnsignedLongFlagChanged

default profiling startTime 11 17 21 25 26 27

Category: Java Virtual Machine / Flag

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

DoubleFlagChanged

default profiling startTime 11 17 21 25 26 27

Category: Java Virtual Machine / Flag

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

BooleanFlagChanged

default profiling startTime 11 17 21 25 26 27

Category: Java Virtual Machine / Flag

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

StringFlagChanged

default profiling startTime 11 17 21 25 26 27

Category: Java Virtual Machine / Flag

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(JVMFlagsEnum 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

IntFlag

default profiling startTime duration end of every chunk 11 17 21 25 26 27

Category: Java Virtual Machine / Flag

Configuration enabled period
default true beginChunk
profiling true beginChunk

Field Type Description
name string Name
value int Value
origin FlagValueOrigin Origin

Examples 3
name string
PerfDataMemorySize
origin FlagValueOrigin
Default
startTime long: millis
384855759998
value int
32768
name string
GlibcMallocArenas
origin FlagValueOrigin
Default
startTime long: millis
358754367449
value int
0
name string
PerfDataMemorySize
origin FlagValueOrigin
Default
startTime long: millis
300603423296
value int
32768

UnsignedIntFlag

default profiling startTime duration end of every chunk 11 17 21 25 26 27

Category: Java Virtual Machine / Flag

Configuration enabled period
default true beginChunk
profiling true beginChunk

Field Type Description
name string Name
value uint Value
origin FlagValueOrigin Origin

Examples 3
name string
ErrorHandlerTest
origin FlagValueOrigin
Default
startTime long: millis
414853957916
value uint
0
name string
ErrorHandlerTest
origin FlagValueOrigin
Default
startTime long: millis
313294856349
value uint
0
name string
StringDeduplicationAgeThreshold
origin FlagValueOrigin
Default
startTime long: millis
378916670745
value uint
3

LongFlag

default profiling startTime duration end of every chunk 11 17 21 25 26 27

Category: Java Virtual Machine / Flag

Configuration enabled period
default true beginChunk
profiling true beginChunk

Field Type Description
name string Name
value long Value
origin FlagValueOrigin Origin

Examples 3
name string
Tier2BackedgeNotifyFreqLog
origin FlagValueOrigin
Default
startTime long: millis
358754386886
value long
14
name string
FreqCountInvocations
origin FlagValueOrigin
Default
startTime long: millis
300603443824
value long
1
name string
LiveNodeCountInliningCutoff
origin FlagValueOrigin
Default
startTime long: millis
378279275426
value long
40000

UnsignedLongFlag

default profiling startTime duration end of every chunk 11 17 21 25 26 27

Category: Java Virtual Machine / Flag

Configuration enabled period
default true beginChunk
profiling true beginChunk

Field Type Description
name string Name
value ulong Value
origin FlagValueOrigin Origin

Examples 3
name string
HeapMaximumCompactionInterval
origin FlagValueOrigin
Default
startTime long: millis
358754411722
value ulong
20
name string
MetadataAllocationFailALotInterval
origin FlagValueOrigin
Default
startTime long: millis
300603477978
value ulong
1000
name string
StartAggressiveSweepingAt
origin FlagValueOrigin
Default
startTime long: millis
378279302336
value ulong
10

DoubleFlag

default profiling startTime duration end of every chunk 11 17 21 25 26 27

Category: Java Virtual Machine / Flag

Configuration enabled period
default true beginChunk
profiling true beginChunk

Field Type Description
name string Name
value double Value
origin FlagValueOrigin Origin

Examples 3
name string
InitialRAMPercentage
origin FlagValueOrigin
Default
startTime long: millis
390643027657
value double
1.5625
name string
ZAllocationSpikeTolerance
origin FlagValueOrigin
Default
startTime long: millis
313294920960
value double
2.0
name string
ZAllocationSpikeTolerance
origin FlagValueOrigin
Default
startTime long: millis
358754434244
value double
2.0

BooleanFlag

default profiling startTime duration end of every chunk 11 17 21 25 26 27

Category: Java Virtual Machine / Flag

Configuration enabled period
default true beginChunk
profiling true beginChunk

Field Type Description
name string Name
value boolean Value
origin FlagValueOrigin Origin

Examples 3
name string
PrintFlagsRanges
origin FlagValueOrigin
Default
startTime long: millis
300603543571
value boolean
false
name string
PromotionFailureALot
origin FlagValueOrigin
Default
startTime long: millis
378279407772
value boolean
false
name string
TraceFrequencyInlining
origin FlagValueOrigin
Default
startTime long: millis
358754495218
value boolean
false

StringFlag

default profiling startTime duration end of every chunk 11 17 21 25 26 27

Category: Java Virtual Machine / Flag

Configuration enabled period
default true beginChunk
profiling true beginChunk

Field Type Description
name string Name
value string Value
origin FlagValueOrigin Origin

Examples 3
name string
NativeMemoryTracking
origin FlagValueOrigin
Default
startTime long: millis
371223686916
value string
off
name string
DumpLoadedClassList
origin FlagValueOrigin
Default
startTime long: millis
305249019163
value string
null
name string
HiMemReportDir
origin FlagValueOrigin
Default
startTime long: millis
380504445347
value string
null

JVM: GC: Collector

GarbageCollection

default profiling startTime duration 11 17 21 25 26 27

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:

// 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
Heap Inspection Initiated GC
gcId uint
925
longestPause Tickspan
334854367
name GCName
SerialOld
startTime long: millis
415370147760
sumOfPauses Tickspan
334854367
cause GCCause
System.gc()
gcId uint
464
longestPause Tickspan
1724382
name GCName
ParallelScavenge
startTime long: millis
446193922929
sumOfPauses Tickspan
1724382
cause GCCause
G1 Humongous Allocation
gcId uint
876
longestPause Tickspan
4464971
name GCName
G1New
startTime long: millis
314890681115
sumOfPauses Tickspan
4464971

ParallelOldGarbageCollection

default profiling startTime duration 11 17 21 25 26 27

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
30337925120
gcId uint
465
startTime long: millis
446195652070

YoungGarbageCollection

default profiling startTime duration 11 17 21 25 26 27

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
977
startTime long: millis
440412816433
tenuringThreshold uint
15
gcId uint
523
startTime long: millis
495868197343
tenuringThreshold uint
15
gcId uint
888
startTime long: millis
319883230244
tenuringThreshold uint
15

OldGarbageCollection

default profiling startTime duration 11 17 21 25 26 27

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
480
startTime long: millis
457883944293
gcId uint
884
startTime long: millis
319456008337
gcId uint
963
startTime long: millis
436917454244

G1GarbageCollection

default profiling startTime duration 11 17 21 25 26 27

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/g1/g1Trace.cpp:

                                                  double predicted_allocation_rate,
                                                  double predicted_marking_length,
                                                  bool prediction_active) {
  send_adaptive_ihop_statistics(threshold,
                                internal_target_occupancy,
                                additional_buffer_size,
                                current_occupancy,
                                predicted_allocation_rate,
                                predicted_marking_length,
                                prediction_active);
}

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 G1NewTracer::send_evacuation_info_event(G1EvacuationInfo* info) {
  EventEvacuationInformation e;

Configuration enabled threshold
default true 0 ms
profiling true 0 ms

Field Type Description
gcId uint GC Identifier
type G1YCType Type

Examples 1
gcId uint
953
startTime long: millis
354500449458
type G1YCType
Prepare Mixed

JVM: GC: Configuration

GCConfiguration

default profiling startTime duration end of every chunk 11 17 21 25 26 27

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:

TRACE_REQUEST_FUNC(G1HeapRegionInformation) {
  G1GC_ONLY(G1HeapRegionEventSender::send_events());
}

// 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
392633607108
usesDynamicGCThreads boolean
true
youngCollector GCName
DefNew
concurrentGCThreads uint
0
gcTimeRatio uint
99
isExplicitGCConcurrent boolean
false
isExplicitGCDisabled boolean
false
oldCollector GCName
ParallelOld
parallelGCThreads uint
4
pauseTarget long: millis
-9223372036854775808
startTime long: millis
462184063181
usesDynamicGCThreads boolean
true
youngCollector GCName
ParallelScavenge
concurrentGCThreads uint
1
gcTimeRatio uint
12
isExplicitGCConcurrent boolean
false
isExplicitGCDisabled boolean
false
oldCollector GCName
G1Old
parallelGCThreads uint
4
pauseTarget long: millis
-9223372036854775808
startTime long: millis
300755834371
usesDynamicGCThreads boolean
true
youngCollector GCName
G1New

GCSurvivorConfiguration

default profiling startTime duration end of every chunk 11 17 21 25 26 27

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
437745581033
initialTenuringThreshold ubyte
7
maxTenuringThreshold ubyte
15
startTime long: millis
489174313709
initialTenuringThreshold ubyte
7
maxTenuringThreshold ubyte
15
startTime long: millis
313458934639

GCTLABConfiguration

default profiling startTime duration end of every chunk 11 17 21 25 26 27

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
380658939077
tlabRefillWasteLimit ulong: bytes
64
usesTLABs boolean
true
minTLABSize ulong: bytes
2048
startTime long: millis
480394826033
tlabRefillWasteLimit ulong: bytes
64
usesTLABs boolean
true
minTLABSize ulong: bytes
2048
startTime long: millis
303187695566
tlabRefillWasteLimit ulong: bytes
64
usesTLABs boolean
true

GCHeapConfiguration

default profiling startTime duration end of every chunk 11 17 21 25 26 27

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
262144000
maxSize ulong: bytes
4192206848
minSize ulong: bytes
8388608
objectAlignment ulong: bytes
8
startTime long: millis
462703953223
usesCompressedOops boolean
true
compressedOopsMode NarrowOopMode
Zero based
heapAddressBits ubyte
32
initialSize ulong: bytes
262144000
maxSize ulong: bytes
4192206848
minSize ulong: bytes
8388608
objectAlignment ulong: bytes
8
startTime long: millis
458070520249
usesCompressedOops boolean
true
compressedOopsMode NarrowOopMode
Zero based
heapAddressBits ubyte
32
initialSize ulong: bytes
262144000
maxSize ulong: bytes
4192206848
minSize ulong: bytes
8388608
objectAlignment ulong: bytes
8
startTime long: millis
305408203050
usesCompressedOops boolean
true

YoungGenerationConfiguration

default profiling startTime duration end of every chunk 11 17 21 25 26 27

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
2514485248
minSize ulong: bytes
1363144
newRatio uint
2
startTime long: millis
369636677830
maxSize ulong: bytes
1397227520
minSize ulong: bytes
87031808
newRatio uint
2
startTime long: millis
452893832339
maxSize ulong: bytes
1397358592
minSize ulong: bytes
87359488
newRatio uint
2
startTime long: millis
471757369758

JVM: GC: Detailed

G1MMU

default profiling startTime 11 17 21 25 26 27

Category: Java Virtual Machine / GC / Detailed

Appearing in: G1GC

Missing in: ParallelGC, SerialGC, ShenandoahGC, ZGC

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/g1Trace.cpp:

void G1OldTracer::report_gc_start_impl(GCCause::Cause cause, const Ticks& timestamp) {
  _shared_gc_info.set_start_timestamp(timestamp);
}

void G1OldTracer::set_gc_cause(GCCause::Cause cause) {
  _shared_gc_info.set_cause(cause);
}

void G1MMUTracer::report_mmu(double time_slice_sec, double gc_time_sec, double max_time_sec) {
  send_g1_mmu_event(time_slice_sec * MILLIUNITS,
                    gc_time_sec * MILLIUNITS,
                    max_time_sec * MILLIUNITS);
}

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();
  }
}

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
900
gcTime long: millis
4
pauseTarget long: millis
200
startTime long: millis
326768662125
timeSlice long: millis
201

EvacuationInformation

default profiling startTime 11 17 21 25 26 27

Category: Java Virtual Machine / GC / Detailed

Appearing in: G1GC

Missing in: ParallelGC, SerialGC, ShenandoahGC, ZGC

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/g1Trace.cpp:

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 G1NewTracer::send_evacuation_info_event(G1EvacuationInfo* 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
7105376
allocationRegionsUsedBefore ulong: bytes
0
bytesCopied ulong: bytes
7105376
cSetRegions uint
250
cSetUsedAfter ulong: bytes
0
cSetUsedBefore ulong: bytes
523174656
gcId uint
962
regionsFreed uint
250
startTime long: millis
356583066187

ObjectCountAfterGC

startTime 11 17 21 25 26 27

Category: Java Virtual Machine / GC / Detailed

Appearing in: G1GC, ParallelGC, SerialGC

Missing in: ShenandoahGC, ZGC

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
count long Count
totalSize ulong: bytes Total Size

Examples 3
count long
23347
gcId uint
909
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
21.0.10.0.1
name string
java/util
startTime long: millis
358978375917
totalSize ulong: bytes
1878992
count long
63460
gcId uint
421
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
21.0.10.0.1
name string
java/lang/invoke
startTime long: millis
379518080756
totalSize ulong: bytes
3046080
count long
398883
gcId uint
860
objectClass Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1041
name string
[B
package Package
null
startTime long: millis
304469688074
totalSize ulong: bytes
65739128

G1EvacuationYoungStatistics

default profiling startTime 11 17 21 25 26 27

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/g1/g1Trace.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
343700805419
statistics G1EvacuationStatistics
allocated ulong: bytes
3249040
directAllocated ulong: bytes
368368
failureUsed ulong: bytes
0
failureWaste ulong: bytes
0
gcId uint
935
regionEndWaste ulong: bytes
0
regionsRefilled uint: bytes
2
undoWaste ulong: bytes
0
used ulong: bytes
3072736
wasted ulong: bytes
1240

G1EvacuationOldStatistics

default profiling startTime 11 17 21 25 26 27

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/g1/g1Trace.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
306838185560
statistics G1EvacuationStatistics
allocated ulong: bytes
0
directAllocated ulong: bytes
0
failureUsed ulong: bytes
0
failureWaste ulong: bytes
0
gcId uint
864
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 27

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/g1/g1Trace.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
266203224
gcId uint
964
lastMarkingDuration long: millis
832
recentAllocationRate double: bytes-per-second
0.0
recentMutatorAllocationSize ulong: bytes
0
recentMutatorDuration long: millis
264
startTime long: millis
357115118552
targetOccupancy ulong: bytes
874512384
threshold ulong: bytes
0
thresholdPercentage float: percentage
0.0

G1AdaptiveIHOP

default profiling startTime 11 17 21 25 26 27

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/g1/g1Trace.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
524288000
currentOccupancy ulong: bytes
264736168
gcId uint
963
ihopTargetOccupancy ulong: bytes
830786764
predictedAllocationRate double: bytes-per-second
2.5270621520287663E8
predictedMarkingDuration long: millis
1659
predictionActive boolean
true
startTime long: millis
356844040506
threshold ulong: bytes
0
thresholdPercentage float: percentage
0.0

PromoteObjectInNewPLAB

profiling startTime eventThread 11 17 21 25 26 27

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
849
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
21088
startTime long: millis
300578331502
tenured boolean
false
tenuringAge uint
0
gcId uint
418
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
plabSize ulong: bytes
32752
startTime long: millis
378280338773
tenured boolean
false
tenuringAge uint
0

PromoteObjectOutsidePLAB

profiling startTime eventThread 11 17 21 25 26 27

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
894
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
42176
startTime long: millis
322166491305
tenured boolean
false
tenuringAge uint
1
gcId uint
436
objectClass Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1041
name string
[Ljava/lang/Object;
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
21.0.10.0.1
name string
java/lang
objectSize ulong: bytes
32784
startTime long: millis
404584169981
tenured boolean
false
tenuringAge uint
0

PromotionFailed

default profiling startTime 11 17 21 25 26 27

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 27

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/g1/g1Trace.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()) {
    // Create JFR structured failure data
    JfrStructCopyFailed evac_failed;
    evac_failed.set_objectCount(ef_info.failed_count());
    evac_failed.set_firstSize(ef_info.first_size());
    evac_failed.set_smallestSize(ef_info.smallest_size());
    evac_failed.set_totalSize(ef_info.total_size());
    // Add to the event
    e.set_gcId(GCId::current());
    e.set_evacuationFailed(evac_failed);
    e.commit();

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 27

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();
  }
}

static JfrStructVirtualSpace to_struct(const VirtualSpaceSummary& summary) {
  JfrStructVirtualSpace space;
  space.set_start((TraceAddress)summary.start());
  space.set_committedEnd((TraceAddress)summary.committed_end());
  space.set_committedSize(summary.committed_size());

Configuration enabled
default true
profiling true

Field Type Description
gcId uint GC Identifier

Examples 1
gcId uint
987
startTime long: millis
385873523188

AllocationRequiringGC

startTime eventThread stackTrace 11 17 21 25 26 27

Category: Java Virtual Machine / GC / Detailed

Appearing in: G1GC, ParallelGC, SerialGC

Missing in: ShenandoahGC, ZGC

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
961
size ulong: bytes
1048576
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
0
lineNumber int
-1
method Method
descriptor string
()Ljava/lang/Object;
hidden boolean
true
modifiers int
1
name string
get
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
true
modifiers int
4112
name string
java.util.stream.Collectors$$Lambda/0x00007efd84140480
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
21.0.10.0.1
name string
java/util/stream
type FrameType
Inlined
truncated boolean
true
startTime long: millis
356316277720
gcId uint
944
size ulong: bytes
56
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
0
lineNumber int
174
method Method
descriptor string
(Ljava/util/function/IntFunction;I)Ljava/util/stream/Stream;
hidden boolean
false
modifiers int
2
name string
mapToObj
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1024
name string
java/util/stream/IntPipeline
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
21.0.10.0.1
name string
java/util/stream
type FrameType
Inlined
truncated boolean
true
startTime long: millis
422117945509
gcId uint
496
size ulong: bytes
272
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
21.0.10.0.1
name string
java/util
type FrameType
JIT compiled
truncated boolean
true
startTime long: millis
470527115251

TenuringDistribution

default profiling startTime 11 17 21 25 26 27

Category: Java Virtual Machine / GC / Detailed

Appearing in: G1GC, SerialGC

Missing in: ParallelGC, ShenandoahGC, ZGC

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
6
gcId uint
854
size ulong: bytes
0
startTime long: millis
302213135373
age uint
4
gcId uint
935
size ulong: bytes
0
startTime long: millis
420932434606

G1HeapRegionTypeChange

startTime 11 17 21 25 26 27

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
to G1HeapRegionType To
start ulong: address Start
used ulong: bytes Used

Examples 1
from G1HeapRegionType
Free
index uint
151
start ulong: address
30484201472
startTime long: millis
300747095969
to G1HeapRegionType
Free
used ulong: bytes
0

ObjectCount

startTime every chunk 11 17 21 25 26 27

Category: Java Virtual Machine / GC / Detailed

Appearing in: G1GC, ParallelGC, SerialGC

Missing in: ShenandoahGC, ZGC

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
count long Count
totalSize ulong: bytes Total Size

Examples 3
count long
45447
gcId uint
854
objectClass Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
8
name string
java/util/LinkedHashMap$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
21.0.10.0.1
name string
java/util
startTime long: millis
302166803471
totalSize ulong: bytes
1817880
count long
47040
gcId uint
421
objectClass Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1041
name string
[I
package Package
null
startTime long: millis
379518080756
totalSize ulong: bytes
38483224
count long
398868
gcId uint
909
objectClass Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1041
name string
[B
package Package
null
startTime long: millis
358978375917
totalSize ulong: bytes
65574264

G1HeapRegionInformation

startTime duration every chunk 11 17 21 25 26 27

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;
  }
};

class VM_G1SendHeapRegionInfoEvents : public VM_Operation {
  virtual void doit() {
    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
start ulong: address Start
used ulong: bytes Used

Examples 1
index uint
406
start ulong: address
31018975232
startTime long: millis
300755783836
type G1HeapRegionType
Free
used ulong: bytes
0

ZPageAllocation

experimental default profiling startTime duration eventThread 11 17 21 25 26 27

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
443844005904

ZThreadPhase

experimental default profiling startTime duration eventThread 11 17 21 25 26 27

Category: Java Virtual Machine / GC / Detailed

Appearing in: ZGC

Missing in: G1GC, ParallelGC, SerialGC, ShenandoahGC

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
219
name string
Concurrent Classes Purge
startTime long: millis
362618744180

ZStatisticsCounter

experimental default profiling startTime duration eventThread 11 17 21 25 26 27

Category: Java Virtual Machine / GC / Detailed

Appearing in: ZGC

Missing in: G1GC, ParallelGC, SerialGC, ShenandoahGC

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
increment ulong Increment
value ulong Value

Examples 1
id ZStatisticsCounterType
Allocation Rate
increment ulong
2097152
startTime long: millis
358013779104
value ulong
27262976

ZStatisticsSampler

experimental default profiling startTime duration eventThread 11 17 21 25 26 27

Category: Java Virtual Machine / GC / Detailed

Appearing in: ZGC

Missing in: G1GC, ParallelGC, SerialGC, ShenandoahGC

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
value ulong Value

Examples 1
id ZStatisticsSamplerType
Concurrent References Process
startTime long: millis
362575075191
value ulong
1334700

ShenandoahHeapRegionStateChange

startTime 11 17 21 25 26 27

Category: Java Virtual Machine / GC / Detailed

Appearing in: ShenandoahGC

Missing in: G1GC, ParallelGC, SerialGC, ZGC

Information about a Shenandoah heap region state 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/shenandoah/shenandoahHeapRegion.cpp:

void ShenandoahHeapRegion::do_uncommit() {
  if (!_heap->is_heap_region_special() && !os::uncommit_memory((char *) _reserved.start(), _reserved.byte_size())) {
    report_java_out_of_memory("Unable to uncommit region");
  }
  if (!_heap->uncommit_bitmap_slice(this)) {
    report_java_out_of_memory("Unable to uncommit bitmaps for region");
  }
  _heap->decrease_committed(ShenandoahHeapRegion::region_size_bytes());
}

void ShenandoahHeapRegion::set_state(RegionState to) {
  EventShenandoahHeapRegionStateChange evt;
  if (evt.should_commit()){
    evt.set_index((unsigned)region_number());
    evt.set_start((uintptr_t)bottom());
    evt.set_used(used());
    evt.set_from(_state);
    evt.set_to(to);
    evt.commit();
  }
  _state = to;
}

Configuration enabled
default false
profiling false

Field Type Description
index uint Index
from ShenandoahHeapRegionState From
to ShenandoahHeapRegionState To
start ulong: address Start
used ulong: bytes Used

Examples 1
from ShenandoahHeapRegionState
Trash
index uint
48
start ulong: address
30217863168
startTime long: millis
318834050228
to ShenandoahHeapRegionState
Empty Committed
used ulong: bytes
0

ShenandoahHeapRegionInformation

startTime duration every chunk 11 17 21 25 26 27

Category: Java Virtual Machine / GC / Detailed

Appearing in: ShenandoahGC

Missing in: G1GC, ParallelGC, SerialGC, ZGC

Information about a specific heap region in the Shenandoah 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/shenandoah/shenandoahJfrSupport.cpp:

void ShenandoahJFRSupport::register_jfr_type_serializers() {
  JfrSerializer::register_serializer(TYPE_SHENANDOAHHEAPREGIONSTATE,
                                     false,
                                     true,
                                     new ShenandoahHeapRegionStateConstant());
}
#endif

class ShenandoahDumpHeapRegionInfoClosure : public ShenandoahHeapRegionClosure {
public:
  virtual void heap_region_do(ShenandoahHeapRegion* r) {
    EventShenandoahHeapRegionInformation evt;
    evt.set_index((unsigned)r->region_number());
    evt.set_state((u8)r->state());
    evt.set_start((uintptr_t)r->bottom());
    evt.set_used(r->used());
    evt.commit();
  }
};

void VM_ShenandoahSendHeapRegionInfoEvents::doit() {
  ShenandoahDumpHeapRegionInfoClosure c;
  ShenandoahHeap::heap()->heap_region_iterate(&c);

Configuration enabled period
default false everyChunk
profiling false everyChunk

Field Type Description
index uint Index
state ShenandoahHeapRegionState State
start ulong: address Start
used ulong: bytes Used

Examples 1
index uint
65
start ulong: address
30235688960
startTime long: millis
319065860806
state ShenandoahHeapRegionState
Empty Committed
used ulong: bytes
0

JVM: GC: Heap

GCHeapSummary

default profiling startTime 11 17 21 25 26 27

Category: Java Virtual Machine / GC / 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/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
heapSpace VirtualSpace struct Heap Space
heapUsed ulong: bytes Heap Used Bytes allocated by objects in the heap

Examples 3
gcId uint
919
heapSpace VirtualSpace
committedEnd ulong: address
31163744256
committedSize ulong: bytes
996212736
reservedEnd ulong: address
34359738368
reservedSize ulong: bytes
4192206848
start ulong: address
30167531520
heapUsed ulong: bytes
358758856
startTime long: millis
392301960062
when GCWhen
Before GC
gcId uint
874
heapSpace VirtualSpace
committedEnd ulong: address
31167873024
committedSize ulong: bytes
1000341504
reservedEnd ulong: address
34359738368
reservedSize ulong: bytes
4192206848
start ulong: address
30167531520
heapUsed ulong: bytes
293607576
startTime long: millis
313460757338
when GCWhen
After GC
gcId uint
435
heapSpace VirtualSpace
committedEnd ulong: address
32966180864
committedSize ulong: bytes
2798649344
reservedEnd ulong: address
34359738368
reservedSize ulong: bytes
4192206848
start ulong: address
30167531520
heapUsed ulong: bytes
264273880
startTime long: millis
400387525979
when GCWhen
After GC

MetaspaceSummary

default profiling startTime 11 17 21 25 26 27

Category: Java Virtual Machine / GC / 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/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
gcThreshold ulong: bytes GC Threshold
metaspace MetaspaceSizes struct Total
dataSpace MetaspaceSizes struct Data
classSpace MetaspaceSizes struct Class

Examples 3
classSpace MetaspaceSizes
committed ulong: bytes
88080384
reserved ulong: bytes
1073741824
used ulong: bytes
86166448
dataSpace MetaspaceSizes
committed ulong: bytes
571342848
reserved ulong: bytes
603979776
used ulong: bytes
569426080
gcId uint
892
gcThreshold ulong: bytes
1098973184
metaspace MetaspaceSizes
committed ulong: bytes
659423232
reserved ulong: bytes
1677721600
used ulong: bytes
655592528
startTime long: millis
322155609360
when GCWhen
After GC
classSpace MetaspaceSizes
committed ulong: bytes
88211456
reserved ulong: bytes
1073741824
used ulong: bytes
86336488
dataSpace MetaspaceSizes
committed ulong: bytes
570753024
reserved ulong: bytes
603979776
used ulong: bytes
568898232
gcId uint
911
gcThreshold ulong: bytes
1098055680
metaspace MetaspaceSizes
committed ulong: bytes
658964480
reserved ulong: bytes
1677721600
used ulong: bytes
655234720
startTime long: millis
371547194479
when GCWhen
After GC
classSpace MetaspaceSizes
committed ulong: bytes
88211456
reserved ulong: bytes
1073741824
used ulong: bytes
86302768
dataSpace MetaspaceSizes
committed ulong: bytes
570818560
reserved ulong: bytes
603979776
used ulong: bytes
568908120
gcId uint
427
gcThreshold ulong: bytes
1098317824
metaspace MetaspaceSizes
committed ulong: bytes
659030016
reserved ulong: bytes
1677721600
used ulong: bytes
655210888
startTime long: millis
384859154830
when GCWhen
Before GC

PSHeapSummary

default profiling startTime 11 17 21 25 26 27

Category: Java Virtual Machine / GC / Heap

Appearing in: ParallelGC

Missing in: G1GC, SerialGC, ShenandoahGC, ZGC

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
oldSpace VirtualSpace struct Old Space
oldObjectSpace ObjectSpace struct Old Object Space
youngSpace VirtualSpace struct Young Space
edenSpace ObjectSpace struct Eden Space
fromSpace ObjectSpace struct From Space
toSpace ObjectSpace struct To Space

Examples 1
edenSpace ObjectSpace
end ulong: address
33926152192
size ulong: bytes
963641344
start ulong: address
32962510848
used ulong: bytes
0
fromSpace ObjectSpace
end ulong: address
33964949504
size ulong: bytes
38797312
start ulong: address
33926152192
used ulong: bytes
0
gcId uint
468
oldObjectSpace ObjectSpace
end ulong: address
31992053760
size ulong: bytes
1824522240
start ulong: address
30167531520
used ulong: bytes
208967640
oldSpace VirtualSpace
committedEnd ulong: address
31992053760
committedSize ulong: bytes
1824522240
reservedEnd ulong: address
32962510848
reservedSize ulong: bytes
2794979328
start ulong: address
30167531520
startTime long: millis
450070594888
toSpace ObjectSpace
end ulong: address
34014232576
size ulong: bytes
35651584
start ulong: address
33978580992
used ulong: bytes
0
when GCWhen
After GC
youngSpace VirtualSpace
committedEnd ulong: address
34014232576
committedSize ulong: bytes
1051721728
reservedEnd ulong: address
34359738368
reservedSize ulong: bytes
1397227520
start ulong: address
32962510848

G1HeapSummary

default profiling startTime 11 17 21 25 26 27

Category: Java Virtual Machine / GC / Heap

Appearing in: G1GC

Missing in: ParallelGC, SerialGC, ShenandoahGC, ZGC

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
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
551550976
edenUsedSize ulong: bytes
2097152
gcId uint
864
numberOfRegions uint
477
startTime long: millis
306834051664
survivorUsedSize ulong: bytes
0
when GCWhen
Before GC

JVM: GC: Metaspace

MetaspaceGCThreshold

default profiling startTime 11 17 21 25 26 27

Category: Java Virtual Machine / GC / Metaspace

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

Examples 3
newValue ulong: bytes
1098317824
oldValue ulong: bytes
1097859072
startTime long: millis
302213089227
updater GCThresholdUpdater
compute_new_size
newValue ulong: bytes
1477509120
oldValue ulong: bytes
1471217664
startTime long: millis
456523510366
updater GCThresholdUpdater
compute_new_size
newValue ulong: bytes
1128202240
oldValue ulong: bytes
1122435072
startTime long: millis
445915781929
updater GCThresholdUpdater
compute_new_size

MetaspaceAllocationFailure

default profiling startTime stackTrace 11 17 21 25 26 27

Category: Java Virtual Machine / GC / Metaspace

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
unsafeAnonymousClassLoader boolean until JDK 15 Unsafe Anonymous Class Loader
size ulong: bytes Size
metadataType MetadataType Metadata Type
metaspaceObjectType MetaspaceObjectType Metaspace Object Type

MetaspaceOOM

default profiling startTime stackTrace 11 17 21 25 26 27

Category: Java Virtual Machine / GC / Metaspace

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
unsafeAnonymousClassLoader boolean until JDK 15 Unsafe Anonymous Class Loader
size ulong: bytes Size
metadataType MetadataType Metadata Type
metaspaceObjectType MetaspaceObjectType Metaspace Object Type

MetaspaceChunkFreeListSummary

default profiling startTime 11 17 21 25 26 27

Category: Java Virtual Machine / GC / Metaspace

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
metadataType MetadataType Metadata Type
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
925
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
415705001545
when GCWhen
After GC
gcId uint
861
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
305222184490
when GCWhen
After GC
gcId uint
424
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
382283597218
when GCWhen
Before GC

JVM: GC: Phases

GCPhasePause

default profiling startTime duration eventThread 11 17 21 25 26 27

Category: Java Virtual Machine / GC / Phases

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
489
name string
GC Pause
startTime long: millis
467444736452
gcId uint
884
name string
GC Pause
startTime long: millis
319456008337
gcId uint
977
name string
GC Pause
startTime long: millis
440412816433

GCPhasePauseLevel1

default profiling startTime duration eventThread 11 17 21 25 26 27

Category: Java Virtual Machine / GC / Phases

Appearing in: G1GC, ParallelGC, SerialGC, ShenandoahGC

Missing in: ZGC

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
439
name string
Post Compact
startTime long: millis
415008503266
gcId uint
871
name string
Finalize Concurrent Mark Cleanup
startTime long: millis
311445921666
gcId uint
928
name string
Notify PhantomReferences
startTime long: millis
420447676958

GCPhasePauseLevel2

default profiling startTime duration eventThread 11 17 21 25 26 27

Category: Java Virtual Machine / GC / Phases

Appearing in: G1GC, ParallelGC, SerialGC

Missing in: ShenandoahGC, ZGC

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
923
name string
Reference Processing
startTime long: millis
410039865033
gcId uint
425
name string
Report Object Count
startTime long: millis
382360314276
gcId uint
865
name string
Purge Unlinked NMethods
startTime long: millis
307113115673

GCPhasePauseLevel3

startTime duration eventThread 11 17 21 25 26 27

Category: Java Virtual Machine / GC / Phases

Appearing in: G1GC, ParallelGC, SerialGC

Missing in: ShenandoahGC, ZGC

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
419
name string
Notify PhantomReferences
startTime long: millis
378339055886
gcId uint
914
name string
Free Code Blobs
startTime long: millis
376520347902
gcId uint
863
name string
Purge Class Loader Data
startTime long: millis
305327282700

GCPhasePauseLevel4

startTime duration eventThread 11 17 21 25 26 27

Category: Java Virtual Machine / GC / Phases

Appearing in: G1GC, ParallelGC

Missing in: SerialGC, ShenandoahGC, ZGC

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
948
name string
Balance queues
startTime long: millis
351463104967
gcId uint
445
name string
Balance queues
startTime long: millis
429945103455

GCPhaseConcurrent

default profiling startTime duration eventThread 11 17 21 25 26 27

Category: Java Virtual Machine / GC / Phases

Appearing in: G1GC, ShenandoahGC, ZGC

Missing in: ParallelGC, SerialGC

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
235
name string
Concurrent evacuation
startTime long: millis
325574273126
gcId uint
234
name string
Concurrent Reset Relocation Set
startTime long: millis
433201156995
gcId uint
871
name string
Concurrent Scan Root Regions
startTime long: millis
310750005402

GCPhaseParallel

default profiling startTime duration eventThread 12 17 21 25 26 27

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/g1/g1RemSet.cpp:

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

  void 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 scan_opt_rem_set_roots(HeapRegion* r) {
    EventGCPhaseParallel event;

    G1OopStarChunkedList* opt_rem_set_list = _pss->oops_into_optional_region(r);

    G1ScanCardClosure scan_cl(_g1h, _pss);
    G1ScanRSForOptionalClosure cl(_g1h, &scan_cl);
    _opt_refs_scanned += opt_rem_set_list->oops_do(&cl, _pss->closures()->raw_strong_oops());
    _opt_refs_memory_used += opt_rem_set_list->used_memory();

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

  void 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 scan_strong_code_roots(HeapRegion* r) {
    EventGCPhaseParallel event;
    // We pass a weak code blobs closure to the remembered set scanning because we want to avoid
    // treating the nmethods visited to act as roots for concurrent marking.
    // We only want to make sure that the oops in the nmethods are adjusted with regard to the
    // objects copied by the current evacuation.
    r->strong_code_roots_do(_pss->closures()->weak_codeblobs());
    event.commit(GCId::current(), _worker_i, G1GCPhaseTimes::phase_name(G1GCPhaseTimes::CodeRoots));
  }

public:
  G1ScanRSForRegionClosure(G1RemSetScanState* scan_state,
                           G1ScanCardClosure* scan_obj_on_card,

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

  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());
}

void G1CollectedHeap::complete_cleaning(BoolObjectClosure* is_alive,
                                        bool class_unloading_occurred) {
  uint num_workers = workers()->active_workers();
  ParallelCleaningTask unlink_task(is_alive, num_workers, class_unloading_occurred, false);
  workers()->run_task(&unlink_task);
}

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:

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_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;

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
274
gcWorkerId uint
0
name string
Finish Mark
startTime long: millis
401379942333
gcId uint
849
gcWorkerId uint
2
name string
CMRefRoots
startTime long: millis
300578123565

JVM: GC: Reference

GCReferenceStatistics

default profiling startTime 11 17 21 25 26 27

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
count ulong Total Count

Examples 3
count ulong
2725
gcId uint
910
startTime long: millis
362528369412
type ReferenceType
Weak reference
count ulong
0
gcId uint
442
startTime long: millis
426515721195
type ReferenceType
Soft reference
count ulong
236
gcId uint
878
startTime long: millis
315629553040
type ReferenceType
Final reference

JVM: Profiling

OldObjectSample

cutoff default profiling startTime eventThread stackTrace 11 17 21 25 26 27

Category: Java Virtual Machine / Profiling

Appearing in: G1GC, ParallelGC, SerialGC, ZGC

Missing in: ShenandoahGC

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/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);

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

  const JfrThreadLocal* const tl = thread->jfr_thread_local();
  assert(tl != NULL, "invariant");
  if (!tl->has_thread_blob()) {
    JfrCheckpointManager::create_thread_blob(thread);
  }
  assert(tl->has_thread_blob(), "invariant");
  return tl->thread_id();
}

static void record_stacktrace(JavaThread* thread) {
  assert(thread != NULL, "invariant");
  if (JfrEventSetting::has_stacktrace(EventOldObjectSample::eventId)) {
    JfrStackTraceRepository::record_and_cache(thread);
  }
}

void ObjectSampler::sample(HeapWord* obj, size_t allocated, JavaThread* thread) {
  assert(thread != NULL, "invariant");
  assert(is_created(), "invariant");
  const traceid thread_id = get_thread_id(thread);
  if (thread_id == 0) {
    return;
  }

src/hotspot/share/jfr/leakprofiler/checkpoint/eventEmitter.cpp:

  if (edge == NULL) {
    // In order to dump out a representation of the event
    // even though it was not reachable / too long to reach,
    // we need to register a top level edge for this object.
    edge = edge_store->put(object_addr);
  } else {
    gc_root_id = edge_store->gc_root_id(edge);
  }

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

  EventOldObjectSample e(UNTIMED);
  e.set_starttime(_start_time);
  e.set_endtime(_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(edge->pointee()));
  e.set_root(gc_root_id);

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

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

Field Type Description
allocationTime Ticks Allocation Time
lastKnownHeapUsage ulong: bytes Last Known Heap Usage
object OldObject Object
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

Examples 3
allocationTime Ticks
360738078449
arrayElements int
-2147483648
lastKnownHeapUsage ulong: bytes
258049384
object OldObject
address ulong: address
30375479640
description string
null
referrer Reference
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
24
name string
jdk/internal/jimage/ImageReader$Directory
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.10.0.1
name string
jdk/internal/jimage
root OldObjectGcRoot
null
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
0
lineNumber int
742
method Method
descriptor string
(Ljdk/internal/jimage/ImageReader$Directory;Ljava/lang/String;Ljava/nio/file/attribute/BasicFileAttributes;)Ljdk/internal/jimage/ImageReader$Directory;
hidden boolean
false
modifiers int
8
name string
create
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
24
name string
jdk/internal/jimage/ImageReader$Directory
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
21.0.10.0.1
name string
jdk/internal/jimage
type FrameType
JIT compiled
truncated boolean
true
startTime long: millis
385600048782
allocationTime Ticks
456523887189
arrayElements int
-2147483648
lastKnownHeapUsage ulong: bytes
238391552
object OldObject
address ulong: address
31801977400
description string
null
referrer Reference
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
24
name string
java/util/concurrent/locks/AbstractQueuedSynchronizer$ConditionNode
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.10.0.1
name string
java/util/concurrent/locks
root OldObjectGcRoot
null
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
10
lineNumber int
1661
method Method
descriptor string
()Ljava/util/concurrent/locks/AbstractQueuedSynchronizer$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$ConditionObject
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.10.0.1
name string
java/util/concurrent/locks
type FrameType
JIT compiled
truncated boolean
false
startTime long: millis
482570022885
allocationTime Ticks
465818007771
arrayElements int
16384
lastKnownHeapUsage ulong: bytes
232331792
object OldObject
address ulong: address
30399620296
description string
null
referrer Reference
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1040
name string
[Ljava/util/concurrent/ConcurrentHashMap$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
21.0.10.0.1
name string
java/util/concurrent
root OldObjectGcRoot
null
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
40
lineNumber int
2431
method Method
descriptor string
([Ljava/util/concurrent/ConcurrentHashMap$Node;[Ljava/util/concurrent/ConcurrentHashMap$Node;)V
hidden boolean
false
modifiers int
18
name string
transfer
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/util/concurrent/ConcurrentHashMap
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
21.0.10.0.1
name string
java/util/concurrent
type FrameType
JIT compiled
truncated boolean
false
startTime long: millis
495845522398

ExecutionSample

default profiling startTime every chunk 11 17 21 25 26 27

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_native_ms = get_monotonic_ms();
    }
  }
}

void JfrThreadSampler::post_run() {
  this->NonJavaThread::post_run();
  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
stackTrace StackTrace Stack Trace
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 8.0 in stage 18.0 (TID 115)
javaThreadId long
1162
osName string
Executor task launch worker for task 8.0 in stage 18.0 (TID 115)
osThreadId long
3855
virtual boolean
false
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
23
lineNumber int
901
method Method
descriptor string
([F)V
hidden boolean
false
modifiers int
2
name string
copyToDouble
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
21.0.10.0.1
name string
java/net
hidden boolean
false
modifiers int
9
name string
org/apache/spark/ml/recommendation/ALS$NormalEquation
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
21.0.10.0.1
name string
java/net
location string
null
name string
null
version string
null
name string
org/apache/spark/ml/recommendation
type FrameType
Inlined
truncated boolean
false
startTime long: millis
301199252871
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 7.0 in stage 18.0 (TID 114)
javaThreadId long
1140
osName string
Executor task launch worker for task 7.0 in stage 18.0 (TID 114)
osThreadId long
3885
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
21.0.10.0.1
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
21.0.10.0.1
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
372013905965
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 9.0 in stage 16.0 (TID 96)
javaThreadId long
1142
osName string
Executor task launch worker for task 9.0 in stage 16.0 (TID 96)
osThreadId long
3846
virtual boolean
false
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
357
lineNumber int
1745
method Method
descriptor string
(IIZLscala/Option;Lorg/apache/spark/ml/recommendation/ALS$LocalIndexEncoder;ZDLorg/apache/spark/ml/recommendation/ALS$LeastSquaresNESolver;DLscala/Tuple2;)[[F
hidden boolean
false
modifiers int
4121
name string
$anonfun$computeFactors$4
type Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.10.0.1
name string
java/net
hidden boolean
false
modifiers int
17
name string
org/apache/spark/ml/recommendation/ALS$
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
21.0.10.0.1
name string
java/net
location string
null
name string
null
version string
null
name string
org/apache/spark/ml/recommendation
type FrameType
JIT compiled
truncated boolean
false
startTime long: millis
379372994250
state ThreadState
STATE_RUNNABLE

NativeMethodSample

default profiling startTime every chunk 11 17 21 25 26 27

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:

void JfrThreadSampler::post_run() {
  this->NonJavaThread::post_run();
  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();
    {
      MutexLocker tlock(Threads_lock, Mutex::_no_safepoint_check_flag);

Configuration enabled period
default true 20 ms
profiling true 20 ms

Field Type Description
sampledThread Thread Thread
stackTrace StackTrace Stack Trace
state ThreadState Thread State

Examples 3
sampledThread Thread
group ThreadGroup
name string
main
parent ThreadGroup
name string
system
parent ThreadGroup
null
javaName string
rpc-boss-3-1
javaThreadId long
1113
osName string
rpc-boss-3-1
osThreadId long
3799
virtual boolean
false
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
0
lineNumber int
-1
method Method
descriptor string
(IJII)I
hidden boolean
false
modifiers int
264
name string
wait
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
0
name string
sun/nio/ch/EPoll
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
21.0.10.0.1
name string
sun/nio/ch
type FrameType
Native
truncated boolean
false
startTime long: millis
302999589757
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/netty4-2-8
javaThreadId long
866
osName string
finagle/netty4-2-8
osThreadId long
3521
virtual boolean
false
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
0
lineNumber int
-1
method Method
descriptor string
(IJII)I
hidden boolean
false
modifiers int
266
name string
epollWait
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
21.0.10.0.1
name string
java/net
hidden boolean
false
modifiers int
17
name string
io/netty/channel/epoll/Native
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
21.0.10.0.1
name string
java/net
location string
null
name string
null
version string
null
name string
io/netty/channel/epoll
type FrameType
Native
truncated boolean
false
startTime long: millis
372613845819
state ThreadState
STATE_RUNNABLE
sampledThread Thread
group ThreadGroup
name string
main
parent ThreadGroup
name string
system
parent ThreadGroup
null
javaName string
SparkUI-1110
javaThreadId long
1110
osName string
SparkUI-1110
osThreadId long
3850
virtual boolean
false
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
0
lineNumber int
-1
method Method
descriptor string
(IJII)I
hidden boolean
false
modifiers int
264
name string
wait
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
0
name string
sun/nio/ch/EPoll
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
21.0.10.0.1
name string
sun/nio/ch
type FrameType
Native
truncated boolean
false
startTime long: millis
353545475074
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:

  bool is_bulk_rebias() const {
    return _bulk_rebias;
  }
};

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* op) {
  assert(event != NULL, "invariant");
  assert(k != NULL, "invariant");
  assert(op != NULL, "invariant");
  assert(event->should_commit(), "invariant");
  event->set_lockClass(k);
  event->set_safepointId(op->safepoint_id());
  event->set_previousOwner(op->biased_locker());
  event->commit();
}

static void post_class_revocation_event(EventBiasedLockClassRevocation* event, Klass* k, VM_BulkRevokeBias* op) {

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 bool doit_prologue()   { return true; }

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

  bool is_bulk_rebias() const {
    return _bulk_rebias;
  }
};

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* op) {
  assert(event != NULL, "invariant");
  assert(k != NULL, "invariant");
  assert(op != 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* op) {
  assert(event != NULL, "invariant");
  assert(k != NULL, "invariant");
  assert(op != NULL, "invariant");
  assert(event->should_commit(), "invariant");
  event->set_lockClass(k);
  event->set_safepointId(op->safepoint_id());
  event->set_previousOwner(op->biased_locker());
  event->commit();
}

static void post_class_revocation_event(EventBiasedLockClassRevocation* event, Klass* k, VM_BulkRevokeBias* op) {
  assert(event != NULL, "invariant");
  assert(k != NULL, "invariant");
  assert(op != NULL, "invariant");
  assert(event->should_commit(), "invariant");
  event->set_revokedClass(k);
  event->set_disableBiasing(!op->is_bulk_rebias());
  event->set_safepointId(op->safepoint_id());
  event->commit();
}

BiasedLocking::Condition BiasedLocking::revoke_and_rebias(Handle obj, bool attempt_rebias, TRAPS) {

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(), &bulk_revoke);
  }
  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 27

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 27

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:

static void post_safepoint_begin_event(EventSafepointBegin& event,
                                       uint64_t safepoint_id,
                                       int thread_count,
                                       int critical_thread_count) {
  if (event.should_commit()) {
    event.set_safepointId(safepoint_id);
    event.set_totalThreadCount(thread_count);
    event.set_jniCriticalThreadCount(critical_thread_count);
    event.commit();
  }
}

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

    Interpreter::notice_safepoints();

    // Make polling safepoint aware
    guarantee (!PageArmed, "invariant") ;
    PageArmed = true;
    os::make_polling_page_unreadable();
  }
}

// Roll all threads forward to a safepoint and suspend them all
void SafepointSynchronize::begin() {
  assert(Thread::current()->is_VM_thread(), "Only VM thread may execute a safepoint");

  EventSafepointBegin begin_event;
  SafepointTracing::begin(VMThread::vm_op_type());

  Universe::heap()->safepoint_synchronize_begin();

  // By getting the Threads_lock, we assure that no threads are about to start or
  // exit. It is released again in SafepointSynchronize::end().
  Threads_lock->lock();

  assert( _state == _not_synchronized, "trying to safepoint synchronize with wrong state");

  int nof_threads = Threads::number_of_threads();

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
679
startTime long: millis
382455338155
totalThreadCount int
173
jniCriticalThreadCount int
0
safepointId ulong
1213
startTime long: millis
362397379737
totalThreadCount int
169
jniCriticalThreadCount int
0
safepointId ulong
1434
startTime long: millis
315556322752
totalThreadCount int
207

SafepointStateSynchronization

startTime duration eventThread 11 17 21 25 26 27

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:

    event.set_totalThreadCount(thread_count);
    event.set_jniCriticalThreadCount(critical_thread_count);
    event.commit();
  }
}

static void post_safepoint_cleanup_event(EventSafepointCleanup& event, uint64_t safepoint_id) {
  if (event.should_commit()) {
    event.set_safepointId(safepoint_id);
    event.commit();
  }
}

static void post_safepoint_synchronize_event(EventSafepointStateSynchronization& event,
                                             uint64_t safepoint_id,
                                             int initial_number_of_threads,
                                             int threads_waiting_to_block,
                                             uint64_t iterations) {
  if (event.should_commit()) {
    event.set_safepointId(safepoint_id);
    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:

  _current_jni_active_count = 0;

  // Set number of threads to wait for
  _waiting_to_block = nof_threads;

  jlong safepoint_limit_time = 0;
  if (SafepointTimeout) {
    // Set the limit time, so that it can be compared to see if this has taken
    // too long to complete.
    safepoint_limit_time = SafepointTracing::start_of_safepoint() + (jlong)SafepointTimeoutDelay * (NANOUNITS / MILLIUNITS);
    timeout_error_printed = false;
  }

  EventSafepointStateSynchronization sync_event;
  int initial_running = 0;

  // Arms the safepoint, _current_jni_active_count and _waiting_to_block must be set before.
  arm_safepoint();

  // Will spin until all threads are safe.
  int iterations = synchronize_threads(safepoint_limit_time, nof_threads, &initial_running);
  assert(_waiting_to_block == 0, "No thread should be running");

#ifndef PRODUCT
  if (safepoint_limit_time != 0) {

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
0
iterations int
1
runningThreadCount int
0
safepointId ulong
727
startTime long: millis
441991912444
initialThreadCount int
1
iterations int
2
runningThreadCount int
0
safepointId ulong
1466
startTime long: millis
323080468523
initialThreadCount int
1
iterations int
2139
runningThreadCount int
0
safepointId ulong
1211
startTime long: millis
360090060799

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,
                                       uint64_t safepoint_id,
                                       int thread_count,
                                       int critical_thread_count) {
  if (event.should_commit()) {
    event.set_safepointId(safepoint_id);
    event.set_totalThreadCount(thread_count);
    event.set_jniCriticalThreadCount(critical_thread_count);
    event.commit();
  }
}

static void post_safepoint_cleanup_event(EventSafepointCleanup& event, uint64_t safepoint_id) {
  if (event.should_commit()) {
    event.set_safepointId(safepoint_id);
    event.commit();
  }
}

static void post_safepoint_synchronize_event(EventSafepointStateSynchronization& event,
                                             uint64_t safepoint_id,
                                             int initial_number_of_threads,
                                             int threads_waiting_to_block,
                                             uint64_t iterations) {

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

  // Update the count of active JNI critical regions
  GCLocker::set_jni_lock_count(_current_jni_active_count);

  post_safepoint_synchronize_event(sync_event,
                                   _safepoint_id,
                                   initial_running,
                                   _waiting_to_block, iterations);

  SafepointTracing::synchronized(nof_threads, initial_running, _nof_threads_hit_polling_page);

  // We do the safepoint cleanup first since a GC related safepoint
  // needs cleanup to be completed before running the GC op.
  EventSafepointCleanup cleanup_event;
  do_cleanup_tasks();
  post_safepoint_cleanup_event(cleanup_event, _safepoint_id);

  post_safepoint_begin_event(begin_event, _safepoint_id, nof_threads, _current_jni_active_count);
  SafepointTracing::cleanup();
}

void SafepointSynchronize::disarm_safepoint() {
  uint64_t active_safepoint_counter = _safepoint_counter;
  {
    JavaThreadIteratorWithHandle jtiwh;

Configuration enabled threshold
default false 10 ms
profiling false 0 ms

Field Type Description
safepointId ulong Safepoint Identifier

Examples 3
safepointId ulong
697
startTime long: millis
404560337729
safepointId ulong
1421
startTime long: millis
311445862726
safepointId ulong
1280
startTime long: millis
421005825245

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:

                                             uint64_t safepoint_id,
                                             int initial_number_of_threads,
                                             int threads_waiting_to_block,
                                             uint64_t iterations) {
  if (event.should_commit()) {
    event.set_safepointId(safepoint_id);
    event.set_initialThreadCount(initial_number_of_threads);
    event.set_runningThreadCount(threads_waiting_to_block);
    event.set_iterations(iterations);
    event.commit();
  }
}

static void post_safepoint_cleanup_task_event(EventSafepointCleanupTask& event,
                                              uint64_t safepoint_id,
                                              const char* name) {
  if (event.should_commit()) {
    event.set_safepointId(safepoint_id);
    event.set_name(name);
    event.commit();
  }
}

static void post_safepoint_end_event(EventSafepointEnd& event, uint64_t safepoint_id) {
  if (event.should_commit()) {

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

    AbstractGangTask("Parallel Safepoint Cleanup"),
    _subtasks(SafepointSynchronize::SAFEPOINT_CLEANUP_NUM_TASKS),
    _cleanup_threads_cl(ParallelSPCleanupThreadClosure(counters)),
    _num_workers(num_workers),
    _counters(counters) {}

  void work(uint worker_id) {
    uint64_t safepoint_id = SafepointSynchronize::safepoint_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);

      post_safepoint_cleanup_task_event(event, safepoint_id, 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();

      post_safepoint_cleanup_task_event(event, safepoint_id, 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();

      post_safepoint_cleanup_task_event(event, safepoint_id, 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();

        post_safepoint_cleanup_task_event(event, safepoint_id, 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();

        post_safepoint_cleanup_task_event(event, safepoint_id, name);
      }
    }

    if (_subtasks.try_claim_task(SafepointSynchronize::SAFEPOINT_CLEANUP_CLD_PURGE)) {
      if (ClassLoaderDataGraph::should_purge_and_reset()) {
        // 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();

        post_safepoint_cleanup_task_event(event, safepoint_id, name);
      }
    }

    if (_subtasks.try_claim_task(SafepointSynchronize::SAFEPOINT_CLEANUP_SYSTEM_DICTIONARY_RESIZE)) {
      if (Dictionary::does_any_dictionary_needs_resizing()) {
        const char* name = "resizing system dictionaries";
        EventSafepointCleanupTask event;
        TraceTime timer(name, TRACETIME_LOG(Info, safepoint, cleanup));
        ClassLoaderDataGraph::resize_dictionaries();

        post_safepoint_cleanup_task_event(event, safepoint_id, name);
      }
    }

    if (_subtasks.try_claim_task(SafepointSynchronize::SAFEPOINT_CLEANUP_REQUEST_OOPSTORAGE_CLEANUP)) {
      // Don't bother reporting event or time for this very short operation.
      // To have any utility we'd also want to report whether needed.
      OopStorage::trigger_cleanup_if_needed();

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
1448
startTime long: millis
319679906738
name string
updating inline caches
safepointId ulong
752
startTime long: millis
455468796510
name string
updating inline caches
safepointId ulong
1302
startTime long: millis
430073297081

SafepointEnd

startTime duration eventThread 11 17 21 25 26 27

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:

static void post_safepoint_cleanup_task_event(EventSafepointCleanupTask& event,
                                              uint64_t safepoint_id,
                                              const char* name) {
  if (event.should_commit()) {
    event.set_safepointId(safepoint_id);
    event.set_name(name);
    event.commit();
  }
}

static void post_safepoint_end_event(EventSafepointEnd& event, uint64_t safepoint_id) {
  if (event.should_commit()) {
    event.set_safepointId(safepoint_id);
    event.commit();
  }
}

// SafepointCheck
SafepointStateTracker::SafepointStateTracker(uint64_t safepoint_id, bool at_safepoint)
  : _safepoint_id(safepoint_id), _at_safepoint(at_safepoint) {}

bool SafepointStateTracker::safepoint_state_changed() {

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

  } // ~JavaThreadIteratorWithHandle

  // Release threads lock, so threads can be created/destroyed again.
  Threads_lock->unlock();

  // Wake threads after local state is correctly set.
  _wait_barrier->disarm();
}

// 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");
  EventSafepointEnd event;
  assert(Thread::current()->is_VM_thread(), "Only VM thread can execute a safepoint");

  disarm_safepoint();

  Universe::heap()->safepoint_synchronize_end();

  SafepointTracing::end();

  post_safepoint_end_event(event, safepoint_id());
}

Configuration enabled threshold
default false 10 ms
profiling false 0 ms

Field Type Description
safepointId ulong Safepoint Identifier

Examples 3
safepointId ulong
711
startTime long: millis
426509753733
safepointId ulong
1255
startTime long: millis
404147801131
safepointId ulong
1387
startTime long: millis
301485840455

ExecuteVMOperation

default profiling startTime duration eventThread 11 17 21 25 26 27

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.
  { MonitorLocker ml(_terminate_lock, Mutex::_no_safepoint_check_flag);
    while(!VMThread::is_terminated()) {
      ml.wait();
    }
  }
}

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_id() : 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
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
15
osName string
JFR Periodic Tasks
osThreadId long
2415
virtual boolean
false
operation VMOperationType
GC_HeapInspection
safepoint boolean
true
safepointId ulong
699
startTime long: millis
404582895442
blocking boolean
true
caller Thread
group ThreadGroup
name string
system
parent ThreadGroup
null
javaName string
JFR Recorder Thread
javaThreadId long
13
osName string
JFR Recorder Thread
osThreadId long
2435
virtual boolean
false
operation VMOperationType
JFRSafepointWrite
safepoint boolean
true
safepointId ulong
1241
startTime long: millis
387281135404
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
22
osName string
JFR Periodic Tasks
osThreadId long
2414
virtual boolean
false
operation VMOperationType
ClassLoaderStatsOperation
safepoint boolean
true
safepointId ulong
1473
startTime long: millis
325731557972

Shutdown

default profiling startTime eventThread stackTrace 11 17 21 25 26 27

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/runtime/thread.cpp:

  JavaThread* thread = JavaThread::current();

#ifdef ASSERT
  _vm_complete = false;
#endif
  // Wait until we are the last non-daemon thread to execute
  { MonitorLocker 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.
      nu.wait(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();

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.

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
385599381191
reason string
No remaining non-daemon Java threads
stackTrace StackTrace
null
startTime long: millis
495844928692
reason string
No remaining non-daemon Java threads
stackTrace StackTrace
null
startTime long: millis
482568282514

SymbolTableStatistics

default profiling startTime duration every chunk 13 17 21 25 26 27

Category: Java Virtual Machine / Runtime / Tables

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_entryCount(statistics._number_of_entries);
  event.set_totalFootprint(statistics._total_footprint);
  event.set_bucketCountMaximum(statistics._maximum_bucket_size);
  event.set_bucketCountAverage(statistics._average_bucket_size);
  event.set_bucketCountVariance(statistics._variance_of_bucket_size);
  event.set_bucketCountStandardDeviation(statistics._stddev_of_bucket_size);
  event.set_insertionRate(statistics._add_rate);
  event.set_removalRate(statistics._remove_rate);
  event.commit();
}

TRACE_REQUEST_FUNC(SymbolTableStatistics) {
  TableStatistics statistics = SymbolTable::get_table_statistics();
  emit_table_statistics<EventSymbolTableStatistics>(statistics);
}

TRACE_REQUEST_FUNC(StringTableStatistics) {
  TableStatistics statistics = StringTable::get_table_statistics();
  emit_table_statistics<EventStringTableStatistics>(statistics);
}

TRACE_REQUEST_FUNC(PlaceholderTableStatistics) {
  TableStatistics statistics = SystemDictionary::placeholders_statistics();
  emit_table_statistics<EventPlaceholderTableStatistics>(statistics);
}

Configuration enabled period
default true 10 s
profiling true 10 s

Field Type Description
bucketCount ulong Bucket Count Number of buckets
entryCount ulong Entry Count Number of all entries
totalFootprint ulong: bytes Total Footprint Total memory footprint (the table itself plus all of the entries)
bucketCountMaximum ulong Maximum Bucket Count The maximum bucket length (entries in a single bucket)
bucketCountAverage float Average Bucket Count The average bucket length
bucketCountVariance float Bucket Count Variance How far bucket lengths are spread out from their average value
bucketCountStandardDeviation float Bucket Count Standard Deviation How far bucket lengths are spread out from their mean (expected) value
insertionRate float Insertion Rate How many items were added since last event (per second)
removalRate float Removal Rate How many items were removed since last event (per second)

Examples 3
bucketCount ulong
65536
bucketCountAverage float
7.815155
bucketCountMaximum ulong
21
bucketCountStandardDeviation float
2.799173
bucketCountVariance float
7.8353696
entryCount ulong
512174
insertionRate float
715.8441
removalRate float
206.59044
startTime long: millis
343435560302
totalFootprint ulong: bytes
55192608
bucketCount ulong
131072
bucketCountAverage float
4.6278152
bucketCountMaximum ulong
17
bucketCountStandardDeviation float
2.1527703
bucketCountVariance float
4.63442
entryCount ulong
606577
insertionRate float
4339.423
removalRate float
22.81793
startTime long: millis
460840426248
totalFootprint ulong: bytes
67145592
bucketCount ulong
131072
bucketCountAverage float
4.2470474
bucketCountMaximum ulong
17
bucketCountStandardDeviation float
2.060319
bucketCountVariance float
4.244914
entryCount ulong
556669
insertionRate float
3500.0303
removalRate float
179.02771
startTime long: millis
463279150141
totalFootprint ulong: bytes
63105696

StringTableStatistics

default profiling startTime duration every chunk 13 17 21 25 26 27

Category: Java Virtual Machine / Runtime / Tables

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_bucketCountStandardDeviation(statistics._stddev_of_bucket_size);
  event.set_insertionRate(statistics._add_rate);
  event.set_removalRate(statistics._remove_rate);
  event.commit();
}

TRACE_REQUEST_FUNC(SymbolTableStatistics) {
  TableStatistics statistics = SymbolTable::get_table_statistics();
  emit_table_statistics<EventSymbolTableStatistics>(statistics);
}

TRACE_REQUEST_FUNC(StringTableStatistics) {
  TableStatistics statistics = StringTable::get_table_statistics();
  emit_table_statistics<EventStringTableStatistics>(statistics);
}

TRACE_REQUEST_FUNC(PlaceholderTableStatistics) {
  TableStatistics statistics = SystemDictionary::placeholders_statistics();
  emit_table_statistics<EventPlaceholderTableStatistics>(statistics);
}

TRACE_REQUEST_FUNC(LoaderConstraintsTableStatistics) {
  TableStatistics statistics = SystemDictionary::loader_constraints_statistics();
  emit_table_statistics<EventLoaderConstraintsTableStatistics>(statistics);
}

Configuration enabled period
default true 10 s
profiling true 10 s

Field Type Description
bucketCount ulong Bucket Count Number of buckets
entryCount ulong Entry Count Number of all entries
totalFootprint ulong: bytes Total Footprint Total memory footprint (the table itself plus all of the entries)
bucketCountMaximum ulong Maximum Bucket Count The maximum bucket length (entries in a single bucket)
bucketCountAverage float Average Bucket Count The average bucket length
bucketCountVariance float Bucket Count Variance How far bucket lengths are spread out from their average value
bucketCountStandardDeviation float Bucket Count Standard Deviation How far bucket lengths are spread out from their mean (expected) value
insertionRate float Insertion Rate How many items were added since last event (per second)
removalRate float Removal Rate How many items were removed since last event (per second)

Examples 3
bucketCount ulong
65536
bucketCountAverage float
1.5910339
bucketCountMaximum ulong
9
bucketCountStandardDeviation float
1.2583152
bucketCountVariance float
1.5833571
entryCount ulong
104270
insertionRate float
657.73846
removalRate float
85.469864
startTime long: millis
449912301592
totalFootprint ulong: bytes
11743848
bucketCount ulong
65536
bucketCountAverage float
1.7760925
bucketCountMaximum ulong
10
bucketCountStandardDeviation float
1.324987
bucketCountVariance float
1.7555906
entryCount ulong
116398
insertionRate float
662.9289
removalRate float
12.215686
startTime long: millis
484528010083
totalFootprint ulong: bytes
13081216
bucketCount ulong
65536
bucketCountAverage float
1.4425507
bucketCountMaximum ulong
9
bucketCountStandardDeviation float
1.2015622
bucketCountVariance float
1.4437516
entryCount ulong
94539
insertionRate float
22.178593
removalRate float
3.1747582
startTime long: millis
333152764359
totalFootprint ulong: bytes
10606872

PlaceholderTableStatistics

default profiling startTime duration every chunk 17 until JDK 20

Category: Java Virtual Machine / Runtime / Tables

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(SymbolTableStatistics) {
  TableStatistics statistics = SymbolTable::get_table_statistics();
  emit_table_statistics<EventSymbolTableStatistics>(statistics);
}

TRACE_REQUEST_FUNC(StringTableStatistics) {
  TableStatistics statistics = StringTable::get_table_statistics();
  emit_table_statistics<EventStringTableStatistics>(statistics);
}

TRACE_REQUEST_FUNC(PlaceholderTableStatistics) {
  TableStatistics statistics = SystemDictionary::placeholders_statistics();
  emit_table_statistics<EventPlaceholderTableStatistics>(statistics);
}

TRACE_REQUEST_FUNC(LoaderConstraintsTableStatistics) {
  TableStatistics statistics = SystemDictionary::loader_constraints_statistics();
  emit_table_statistics<EventLoaderConstraintsTableStatistics>(statistics);
}

TRACE_REQUEST_FUNC(ProtectionDomainCacheTableStatistics) {
  TableStatistics statistics = SystemDictionary::protection_domain_cache_statistics();
  emit_table_statistics<EventProtectionDomainCacheTableStatistics>(statistics);
}

Configuration enabled period
default true 10 s
profiling true 10 s

Field Type Description
bucketCount ulong Bucket Count Number of buckets
entryCount ulong Entry Count Number of all entries
totalFootprint ulong: bytes Total Footprint Total memory footprint (the table itself plus all of the entries)
bucketCountMaximum ulong Maximum Bucket Count The maximum bucket length (entries in a single bucket)
bucketCountAverage float Average Bucket Count The average bucket length
bucketCountVariance float Bucket Count Variance How far bucket lengths are spread out from their average value
bucketCountStandardDeviation float Bucket Count Standard Deviation How far bucket lengths are spread out from their mean (expected) value
insertionRate float Insertion Rate How many items were added since last event (per second)
removalRate float Removal Rate How many items were removed since last event (per second)

LoaderConstraintsTableStatistics

default profiling startTime duration every chunk 17 until JDK 20

Category: Java Virtual Machine / Runtime / Tables

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(StringTableStatistics) {
  TableStatistics statistics = StringTable::get_table_statistics();
  emit_table_statistics<EventStringTableStatistics>(statistics);
}

TRACE_REQUEST_FUNC(PlaceholderTableStatistics) {
  TableStatistics statistics = SystemDictionary::placeholders_statistics();
  emit_table_statistics<EventPlaceholderTableStatistics>(statistics);
}

TRACE_REQUEST_FUNC(LoaderConstraintsTableStatistics) {
  TableStatistics statistics = SystemDictionary::loader_constraints_statistics();
  emit_table_statistics<EventLoaderConstraintsTableStatistics>(statistics);
}

TRACE_REQUEST_FUNC(ProtectionDomainCacheTableStatistics) {
  TableStatistics statistics = SystemDictionary::protection_domain_cache_statistics();
  emit_table_statistics<EventProtectionDomainCacheTableStatistics>(statistics);
}

TRACE_REQUEST_FUNC(CompilerStatistics) {
  EventCompilerStatistics event;
  event.set_compileCount(CompileBroker::get_total_compile_count());
  event.set_bailoutCount(CompileBroker::get_total_bailout_count());

Configuration enabled period
default true 10 s
profiling true 10 s

Field Type Description
bucketCount ulong Bucket Count
entryCount ulong Entry Count Number of all entries
totalFootprint ulong: bytes Total Footprint Total memory footprint (the table itself plus all of the entries)
bucketCountMaximum ulong Maximum Bucket Count The maximum bucket length (entries in a single bucket)
bucketCountAverage float Average Bucket Count The average bucket length
bucketCountVariance float Bucket Count Variance How far bucket lengths are spread out from their average value
bucketCountStandardDeviation float Bucket Count Standard Deviation How far bucket lengths are spread out from their mean (expected) value
insertionRate float Insertion Rate How many items were added since last event (per second)
removalRate float Removal Rate How many items were removed since last event (per second)

ProtectionDomainCacheTableStatistics

default profiling startTime duration every chunk 17 until JDK 20

Category: Java Virtual Machine / Runtime / Tables

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(PlaceholderTableStatistics) {
  TableStatistics statistics = SystemDictionary::placeholders_statistics();
  emit_table_statistics<EventPlaceholderTableStatistics>(statistics);
}

TRACE_REQUEST_FUNC(LoaderConstraintsTableStatistics) {
  TableStatistics statistics = SystemDictionary::loader_constraints_statistics();
  emit_table_statistics<EventLoaderConstraintsTableStatistics>(statistics);
}

TRACE_REQUEST_FUNC(ProtectionDomainCacheTableStatistics) {
  TableStatistics statistics = SystemDictionary::protection_domain_cache_statistics();
  emit_table_statistics<EventProtectionDomainCacheTableStatistics>(statistics);
}

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());

Configuration enabled period
default true 10 s
profiling true 10 s

Field Type Description
bucketCount ulong Bucket Count Number of buckets
entryCount ulong Entry Count Number of all entries
totalFootprint ulong: bytes Total Footprint Total memory footprint (the table itself plus all of the entries)
bucketCountMaximum ulong Maximum Bucket Count The maximum bucket length (entries in a single bucket)
bucketCountAverage float Average Bucket Count The average bucket length
bucketCountVariance float Bucket Count Variance How far bucket lengths are spread out from their average value
bucketCountStandardDeviation float Bucket Count Standard Deviation How far bucket lengths are spread out from their mean (expected) value
insertionRate float Insertion Rate How many items were added since last event (per second)
removalRate float Removal Rate How many items were removed since last event (per second)

ThreadDump

default profiling startTime duration every chunk 11 17 21 25 26 27

Category: Java Virtual Machine / Runtime

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 3
result string
2026-03-15 00:55:18 Full thread dump OpenJDK 64-Bit Server VM (21.0.10.0.1+1-LTS mixed mode, sharing): Threads class SMR info: _java_thread_list=0x00007f62a06fef20, length=162, elements={ 0x00007f6378057cf0, 0x00007f6378132130, 0x00007f6378133670, 0x00007f6378134dd0, 0x00007f63781363e0, 0x00007f637
startTime long: millis
415082864298
result string
2026-03-15 00:54:17 Full thread dump OpenJDK 64-Bit Server VM (21.0.10.0.1+1-LTS mixed mode, sharing): Threads class SMR info: _java_thread_list=0x00007efd583edc80, length=90, elements={ 0x00007efdfc057d00, 0x00007efdfc196b40, 0x00007efdfc1980b0, 0x00007efdfc199840, 0x00007efdfc19ae80, 0x00007efdfc
startTime long: millis
343486920049
result string
2026-03-15 00:55:53 Full thread dump OpenJDK 64-Bit Server VM (21.0.10.0.1+1-LTS mixed mode, sharing): Threads class SMR info: _java_thread_list=0x00007fc8340c60c0, length=117, elements={ 0x00007fc8f8057cd0, 0x00007fc8f80ac8a0, 0x00007fc8f80adde0, 0x00007fc8f80af540, 0x00007fc8f80b0b50, 0x00007fc8f
startTime long: millis
449912313274

NativeLibrary

default profiling startTime every chunk 11 17 21 25 26 27

Category: Java Virtual Machine / Runtime

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
140501270466560
name string
/lib/x86_64-linux-gnu/libz.so.1
startTime long: millis
371223507910
topAddress ulong: address
140501270581248
baseAddress ulong: address
140065309331456
name string
/opt/hostedtoolcache/Java_SapMachine_jdk/21.0.10-0.1/x64/lib/libnet.so
startTime long: millis
382281575383
topAddress ulong: address
140065309388800
baseAddress ulong: address
139629432872960
name string
/lib64/ld-linux-x86-64.so.2
startTime long: millis
300603388180
topAddress ulong: address
139629433110528

ModuleRequire

default profiling startTime every chunk 11 17 21 25 26 27

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

Examples 3
requiredModule Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.10.0.1
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$AppClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.10.0.1
name string
jdk/internal/loader
location string
jrt:/jdk.jstatd
name string
jdk.jstatd
version string
21.0.10.0.1
startTime long: millis
302050874286
requiredModule Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.10.0.1
source Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.10.0.1
name string
java/net
location string
null
name string
jdk.proxy7
version string
null
startTime long: millis
379407566126
requiredModule Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.10.0.1
source Module
classLoader ClassLoader
name string
platform
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
10
name string
jdk/internal/loader/ClassLoaders$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
21.0.10.0.1
name string
jdk/internal/loader
location string
jrt:/java.scripting
name string
java.scripting
version string
21.0.10.0.1
startTime long: millis
362395773707

ModuleExport

default profiling startTime every chunk 11 17 21 25 26 27

Category: Java Virtual Machine / Runtime / Modules

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
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
21.0.10.0.1
name string
java/net
location string
null
name string
null
version string
null
name string
org/apache/spark/unsafe/array
startTime long: millis
379407848663
targetModule Module
null
exportedPackage 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
21.0.10.0.1
name string
jdk/internal/logger
startTime long: millis
362396126648
targetModule Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.logging
name string
java.logging
version string
21.0.10.0.1
exportedPackage 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
21.0.10.0.1
name string
java/nio/file
startTime long: millis
302051295364
targetModule Module
null

Java Application

ThreadStart

default profiling startTime eventThread stackTrace 11 17 21 25 26 27

Category: 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/support/jfrThreadLocal.cpp:

void JfrThreadLocal::set_thread_blob(const JfrBlobHandle& ref) {
  assert(!_thread.valid(), "invariant");
  _thread = ref;
}

const JfrBlobHandle& JfrThreadLocal::thread_blob() const {
  return _thread;
}

static void send_java_thread_start_event(JavaThread* jt) {
  EventThreadStart event;
  event.set_thread(jt->jfr_thread_local()->thread_id());
  event.set_parentThread(jt->jfr_thread_local()->parent_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);

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.set_parentThread((traceid)0);
#if INCLUDE_JFR
    if (EventThreadStart::is_stacktrace_enabled()) {
      jt->jfr_thread_local()->set_cached_stack_trace_id((traceid)0);
      event.commit();
      jt->jfr_thread_local()->clear_cached_stack_trace();
    } else
#endif
    {
      event.commit();
    }
  }
}

src/hotspot/share/prims/jvm.cpp:

  if (native_thread->osthread() == NULL) {
    // No one should hold a reference to the 'native_thread'.
    native_thread->smr_delete();
    if (JvmtiExport::should_post_resource_exhausted()) {
      JvmtiExport::post_resource_exhausted(
        JVMTI_RESOURCE_EXHAUSTED_OOM_ERROR | JVMTI_RESOURCE_EXHAUSTED_THREADS,
        os::native_thread_creation_failed_msg());
    }
    THROW_MSG(vmSymbols::java_lang_OutOfMemoryError(),
              os::native_thread_creation_failed_msg());
  }

#if INCLUDE_JFR
  if (JfrRecorder::is_recording() && EventThreadStart::is_enabled() &&
      EventThreadStart::is_stacktrace_enabled()) {
    JfrThreadLocal* tl = native_thread->jfr_thread_local();
    // skip Thread.start() and Thread.start0()
    tl->set_cached_stack_trace_id(JfrStackTraceRepository::record(thread, 2));
  }
#endif

  Thread::start(native_thread);

JVM_END

Configuration enabled stackTrace
default true true
profiling true true

Field Type Description
thread Thread New Java Thread
parentThread Thread Parent Java Thread

Examples 3
parentThread Thread
group ThreadGroup
name string
main
parent ThreadGroup
name string
system
parent ThreadGroup
null
javaName string
block-manager-ask-thread-pool-28
javaThreadId long
1246
osName string
block-manager-ask-thread-pool-28
osThreadId long
3972
virtual boolean
false
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
2
lineNumber int
2577
method Method
descriptor string
(Ljava/lang/Thread;Ljdk/internal/vm/ThreadContainer;)V
hidden boolean
false
modifiers int
1
name string
start
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
0
name string
java/lang/System$2
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
21.0.10.0.1
name string
java/lang
type FrameType
Inlined
truncated boolean
false
startTime long: millis
302220091337
thread Thread
group ThreadGroup
name string
main
parent ThreadGroup
name string
system
parent ThreadGroup
null
javaName string
block-manager-ask-thread-pool-29
javaThreadId long
1247
osName string
block-manager-ask-thread-pool-29
osThreadId long
3973
virtual boolean
false
parentThread Thread
group ThreadGroup
name string
main
parent ThreadGroup
name string
system
parent ThreadGroup
null
javaName string
dispatcher-BlockManagerEndpoint1
javaThreadId long
1107
osName string
dispatcher-BlockManagerEndpoint1
osThreadId long
3847
virtual boolean
false
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
2
lineNumber int
2577
method Method
descriptor string
(Ljava/lang/Thread;Ljdk/internal/vm/ThreadContainer;)V
hidden boolean
false
modifiers int
1
name string
start
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
0
name string
java/lang/System$2
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
21.0.10.0.1
name string
java/lang
type FrameType
Inlined
truncated boolean
false
startTime long: millis
411708239124
thread Thread
group ThreadGroup
name string
main
parent ThreadGroup
name string
system
parent ThreadGroup
null
javaName string
block-manager-storage-async-thread-pool-81
javaThreadId long
1285
osName string
block-manager-storage-async-thread-pool-81
osThreadId long
4061
virtual boolean
false
parentThread Thread
group ThreadGroup
name string
main
parent ThreadGroup
name string
system
parent ThreadGroup
null
javaName string
dispatcher-BlockManagerEndpoint1
javaThreadId long
1111
osName string
dispatcher-BlockManagerEndpoint1
osThreadId long
3810
virtual boolean
false
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
2
lineNumber int
2577
method Method
descriptor string
(Ljava/lang/Thread;Ljdk/internal/vm/ThreadContainer;)V
hidden boolean
false
modifiers int
1
name string
start
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
0
name string
java/lang/System$2
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
21.0.10.0.1
name string
java/lang
type FrameType
Inlined
truncated boolean
false
startTime long: millis
380661685379
thread Thread
group ThreadGroup
name string
main
parent ThreadGroup
name string
system
parent ThreadGroup
null
javaName string
block-manager-storage-async-thread-pool-41
javaThreadId long
1224
osName string
block-manager-storage-async-thread-pool-41
osThreadId long
3942
virtual boolean
false

ThreadEnd

default profiling startTime eventThread 11 17 21 25 26 27

Category: 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/runtime/java.cpp:

#if INCLUDE_JVMCI
  JVMCI::shutdown();
#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:

      send_java_thread_start_event((JavaThread*)t);
    }
  }
  if (t->jfr_thread_local()->has_cached_stack_trace()) {
    t->jfr_thread_local()->clear_cached_stack_trace();
  }
}

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");
  if (JfrRecorder::is_recording()) {
    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");

Configuration enabled
default true
profiling true

Field Type Description
thread Thread Java Thread

Examples 3
startTime long: millis
401209691679
thread Thread
group ThreadGroup
name string
main
parent ThreadGroup
name string
system
parent ThreadGroup
null
javaName string
block-manager-ask-thread-pool-13
javaThreadId long
1184
osName string
block-manager-ask-thread-pool-13
osThreadId long
3936
virtual boolean
false
startTime long: millis
330162215647
thread Thread
group ThreadGroup
name string
main
parent ThreadGroup
name string
system
parent ThreadGroup
null
javaName string
map-output-dispatcher-3
javaThreadId long
1121
osName string
map-output-dispatcher-3
osThreadId long
3807
virtual boolean
false
startTime long: millis
414835392333
thread Thread
group ThreadGroup
name string
main
parent ThreadGroup
name string
system
parent ThreadGroup
null
javaName string
block-manager-ask-thread-pool-6
javaThreadId long
1172
osName string
block-manager-ask-thread-pool-6
osThreadId long
3884
virtual boolean
false

ThreadSleep

default profiling startTime duration eventThread stackTrace 11 17 21 25 26 27

Category: 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/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
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
5
lineNumber int
474
method Method
descriptor string
(Ljdk/internal/event/ThreadSleepEvent;)V
hidden boolean
false
modifiers int
10
name string
afterSleep
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/lang/Thread
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
21.0.10.0.1
name string
java/lang
type FrameType
Inlined
truncated boolean
false
startTime long: millis
353418245106
time long: millis
10000000
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
5
lineNumber int
474
method Method
descriptor string
(Ljdk/internal/event/ThreadSleepEvent;)V
hidden boolean
false
modifiers int
10
name string
afterSleep
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/lang/Thread
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
21.0.10.0.1
name string
java/lang
type FrameType
Inlined
truncated boolean
false
startTime long: millis
300583844916
time long: millis
200000000
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
5
lineNumber int
474
method Method
descriptor string
(Ljdk/internal/event/ThreadSleepEvent;)V
hidden boolean
false
modifiers int
10
name string
afterSleep
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/lang/Thread
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
21.0.10.0.1
name string
java/lang
type FrameType
Inlined
truncated boolean
false
startTime long: millis
376211375064
time long: millis
10000000

ThreadPark

default profiling startTime duration eventThread stackTrace 11 17 21 25 26 27

Category: 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/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
address ulong: address
30344797256
parkedClass Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/util/concurrent/locks/AbstractQueuedSynchronizer$ConditionObject
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.10.0.1
name string
java/util/concurrent/locks
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
0
lineNumber int
-1
method Method
descriptor string
(ZJ)V
hidden boolean
false
modifiers int
257
name string
park
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
17
name string
jdk/internal/misc/Unsafe
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.10.0.1
name string
jdk/internal/misc
type FrameType
Native
truncated boolean
false
startTime long: millis
376054668318
timeout long: nanos
99999930
until long: epochmillis
-9223372036854775808
address ulong: address
30313910736
parkedClass Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/util/concurrent/locks/AbstractQueuedSynchronizer$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
21.0.10.0.1
name string
java/util/concurrent/locks
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
0
lineNumber int
-1
method Method
descriptor string
(ZJ)V
hidden boolean
false
modifiers int
257
name string
park
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
17
name string
jdk/internal/misc/Unsafe
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
21.0.10.0.1
name string
jdk/internal/misc
type FrameType
Native
truncated boolean
false
startTime long: millis
301536963578
timeout long: nanos
-9223372036854775808
until long: epochmillis
-9223372036854775808
address ulong: address
31745681736
parkedClass 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
21.0.10.0.1
name string
java/util/concurrent/locks
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
0
lineNumber int
-1
method Method
descriptor string
(ZJ)V
hidden boolean
false
modifiers int
257
name string
park
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
17
name string
jdk/internal/misc/Unsafe
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
21.0.10.0.1
name string
jdk/internal/misc
type FrameType
Native
truncated boolean
false
startTime long: millis
359819216457
timeout long: nanos
-9223372036854775808
until long: epochmillis
-9223372036854775808

JavaMonitorEnter

default profiling startTime duration eventThread stackTrace 11 17 21 25 26 27

Category: 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/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(_contentions >= 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(&_contentions);

  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
previousOwner Thread Previous Monitor Owner
address ulong: address Monitor Address

Examples 3
address ulong: address
139628787515920
monitorClass Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/lang/Object
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
21.0.10.0.1
name string
java/lang
previousOwner Thread
group ThreadGroup
name string
finagle/netty4
parent ThreadGroup
name string
main
parent ThreadGroup
name string
system
parent ThreadGroup
null
javaName string
finagle/netty4-2-7
javaThreadId long
1900
osName string
finagle/netty4-2-7
osThreadId long
4663
virtual boolean
false
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
8
lineNumber int
162
method Method
descriptor string
(Lcom/twitter/finagle/http/Request;)Lcom/twitter/util/Future;
hidden boolean
false
modifiers int
1
name string
apply
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
21.0.10.0.1
name string
java/net
hidden boolean
false
modifiers int
1
name string
org/renaissance/twitter/finagle/FinagleChirper$Master
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.10.0.1
name string
java/net
location string
null
name string
null
version string
null
name string
org/renaissance/twitter/finagle
type FrameType
Interpreted
truncated boolean
true
startTime long: millis
374842939143
address ulong: address
140498851746432
monitorClass Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/util/HashMap
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.10.0.1
name string
java/util
previousOwner Thread
group ThreadGroup
name string
main
parent ThreadGroup
name string
system
parent ThreadGroup
null
javaName string
Executor task launch worker for task 7.0 in stage 18.0 (TID 114)
javaThreadId long
1140
osName string
Executor task launch worker for task 7.0 in stage 18.0 (TID 114)
osThreadId long
3885
virtual boolean
false
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
96
lineNumber int
114
method Method
descriptor string
(Ljava/lang/invoke/MethodHandles$Lookup;Ljava/util/Map;Ljava/util/Map;Ljava/lang/invoke/SerializedLambda;)Ljava/lang/Object;
hidden boolean
false
modifiers int
1
name string
deserializeLambdaOrNull
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
21.0.10.0.1
name string
java/net
hidden boolean
false
modifiers int
17
name string
scala/runtime/LambdaDeserializer$
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
21.0.10.0.1
name string
java/net
location string
null
name string
null
version string
null
name string
scala/runtime
type FrameType
Inlined
truncated boolean
true
startTime long: millis
404665992466
address ulong: address
140062440333488
monitorClass Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/lang/Object
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
21.0.10.0.1
name string
java/lang
previousOwner 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
1825
osName string
finagle/netty4-2-5
osThreadId long
4588
virtual boolean
false
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
8
lineNumber int
162
method Method
descriptor string
(Lcom/twitter/finagle/http/Request;)Lcom/twitter/util/Future;
hidden boolean
false
modifiers int
1
name string
apply
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
21.0.10.0.1
name string
java/net
hidden boolean
false
modifiers int
1
name string
org/renaissance/twitter/finagle/FinagleChirper$Master
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
21.0.10.0.1
name string
java/net
location string
null
name string
null
version string
null
name string
org/renaissance/twitter/finagle
type FrameType
Interpreted
truncated boolean
true
startTime long: millis
486328990566

JavaMonitorWait

default profiling startTime duration eventThread stackTrace 11 17 21 25 26 27

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
139626100508592
monitorClass Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
0
name string
java/util/TaskQueue
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
21.0.10.0.1
name string
java/util
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name string
main
parent ThreadGroup
name string
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bootstrap
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package Package
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module Module
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0

JavaMonitorInflate

profiling startTime duration eventThread stackTrace 11 17 21 25 26 27

Category: 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/runtime/synchronizer.cpp:

  if (log_is_enabled(Debug, monitorinflation)) {
    ls = &lsh_debug;
  } else if ((tally != 0 || inUseTally != 0) &&
             log_is_enabled(Info, monitorinflation)) {
    ls = &lsh_info;
  }
  if (ls != NULL) {
    ls->print_cr("omFlush: jt=" INTPTR_FORMAT ", free_monitor_tally=%d"
                 ", in_use_monitor_tally=%d" ", omFreeProvision=%d",
                 p2i(Self), tally, inUseTally, Self->omFreeProvision);
  }
}

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:

    return;
  }
  inflate(Thread::current(), 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
address ulong: address Monitor Address
cause InflateCause Monitor Inflation Cause Cause of inflation

ObjectAllocationInNewTLAB

profiling startTime eventThread stackTrace 11 17 21 25 26 27

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
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modifiers int
2
name string
java/util/ArrayList$Itr
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java/util/ArrayList
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java/util
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378261135597
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allocationSize ulong: bytes
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(Ljava/io/OutputStream;ILnet/jpountz/lz4/LZ4Compressor;Ljava/util/zip/Checksum;Z)V
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21.0.10.0.1
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startTime long: millis
359090277992
tlabSize ulong: bytes
941408

ObjectAllocationOutsideTLAB

profiling startTime eventThread stackTrace 11 17 21 25 26 27

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
32784
objectClass Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1041
name string
[B
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frames StackFrame
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94
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startTime long: millis
386406190675

JavaErrorThrow

default profiling startTime duration stackTrace 11 17 21 25 26 27

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
thrownClass Class Class

Examples 3
message string
static Lorg/apache/spark/sql/catalyst/encoders/ExpressionEncoder$Serializer;.<clinit>()V
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
7
lineNumber int
68
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static Lorg/apache/spark/util/CollectionAccumulator;.<clinit>()V
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FileWrite

default profiling startTime duration stackTrace 11 17 21 25 26 27

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/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/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();

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/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;

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
80
path string
/home/runner/work/jfrevents/jfrevents/harness-004835-14481387407603099569/apache-spark/als/blockmgr-e8d91817-15f5-4af2-b242-de05c5285561/03/shuffle_5_213_0.checksum.ADLER32.b43d3366-d327-4e51-92aa-5712917fe450
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
21.0.10.0.1
name string
java/io
type FrameType
JIT compiled
truncated boolean
false
startTime long: millis
319709706475

JavaExceptionThrow

startTime duration stackTrace 11 17 21 25 26 27

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
thrownClass Class Class

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
21.0.10.0.1
name string
java/lang
type FrameType
JIT compiled
truncated boolean
false
startTime long: millis
371914175760
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
21.0.10.0.1
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
21.0.10.0.1
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
21.0.10.0.1
name string
java/lang
type FrameType
Inlined
truncated boolean
true
startTime long: millis
301191208897
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
21.0.10.0.1
name string
java/io
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
21.0.10.0.1
name string
java/lang
type FrameType
JIT compiled
truncated boolean
true
startTime long: millis
353639165896
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
21.0.10.0.1
name string
java/io

SocketRead

default profiling startTime duration stackTrace 11 17 21 25 26 27

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

Category: Java Application

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/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.Socket$SocketInputStream")
final class SocketInputStreamInstrumentor {

    private SocketInputStreamInstrumentor() {
    }

    @SuppressWarnings("deprecation")
    @JIInstrumentationMethod
    public int read(byte b[], int off, int length) throws IOException {
        SocketReadEvent event = SocketReadEvent.EVENT.get();
        if (!event.isEnabled()) {
            return read(b, off, length);
        }
        int bytesRead = 0;
        try {
            event.begin();
            bytesRead = read(b, off, length);
        } finally {
            event.end();
            if (event.shouldCommit()) {
                InetAddress remote = parent.getInetAddress();

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/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;

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

FileRead

default profiling startTime duration stackTrace 11 17 21 25 26 27

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

Category: Java Application

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/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/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 {

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/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;

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

FileForce

default profiling startTime duration stackTrace 11 17 21 25 26 27

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/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();

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;

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 27

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/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/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/SocketOutputStreamInstrumentor.java:

/**
 * See {@link JITracer} for an explanation of this code.
 */
@JIInstrumentationTarget("java.net.Socket$SocketOutputStream")
final class SocketOutputStreamInstrumentor {

    private SocketOutputStreamInstrumentor() {
    }

    @SuppressWarnings("deprecation")
    @JIInstrumentationMethod
    public void write(byte b[], int off, int len) throws IOException {
        SocketWriteEvent event = SocketWriteEvent.EVENT.get();
        if (!event.isEnabled()) {
            write(b, off, len);
            return;
        }
        int bytesWritten = 0;
        try {
            event.begin();
            write(b, off, len);
            bytesWritten = len;
        } finally {
            event.end() ;

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;

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

Java Application Statistics

JavaThreadStatistics

default profiling startTime duration every chunk 11 17 21 25 26 27

Category: Java Application / Statistics

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
1778
activeCount long
54
daemonCount long
53
peakCount long
272
startTime long: millis
485536149848
accumulatedCount long
1385
activeCount long
91
daemonCount long
90
peakCount long
273
startTime long: millis
344507031241
accumulatedCount long
1194
activeCount long
170
daemonCount long
169
peakCount long
273
startTime long: millis
371548663546

ClassLoadingStatistics

default profiling startTime duration every chunk 11 17 21 25 26 27

Category: Java Application / Statistics

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
112374
startTime long: millis
459108184915
unloadedClassCount long
3226
loadedClassCount long
132129
startTime long: millis
481398612114
unloadedClassCount long
8427
loadedClassCount long
96448
startTime long: millis
333064530727
unloadedClassCount long
2359

ClassLoaderStatistics

default profiling startTime duration every chunk 11 17 21 25 26 27

Category: Java Application / Statistics

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
parentClassLoader ClassLoader Parent Class Loader
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
3176
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
21.0.10.0.1
name string
jdk/internal/reflect
classLoaderData ulong: address
140065197188192
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
21.0.10.0.1
name string
java/net
startTime long: millis
378277555885
blockSize ulong: bytes
3440
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
21.0.10.0.1
name string
jdk/internal/reflect
classLoaderData ulong: address
139626771939632
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
21.0.10.0.1
name string
java/net
startTime long: millis
300602866112
blockSize ulong: bytes
3176
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
21.0.10.0.1
name string
jdk/internal/reflect
classLoaderData ulong: address
140501167088192
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
21.0.10.0.1
name string
java/net
startTime long: millis
358753561009

ThreadAllocationStatistics

default profiling startTime every chunk 11 17 21 25 26 27

Category: Java Application / Statistics

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
    MutexLocker 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

Examples 3
allocated ulong: bytes
2800
startTime long: millis
300603303561
thread Thread
group ThreadGroup
name string
InnocuousThreadGroup
parent ThreadGroup
name string
system
parent ThreadGroup
null
javaName string
Common-Cleaner
javaThreadId long
17
osName string
Common-Cleaner
osThreadId long
2408
virtual boolean
false
allocated ulong: bytes
148702144
startTime long: millis
378279143750
thread Thread
group ThreadGroup
name string
finagle/netty4
parent ThreadGroup
name string
main
parent ThreadGroup
name string
system
parent ThreadGroup
null
javaName string
finagle/netty4-2-1
javaThreadId long
859
osName string
finagle/netty4-2-1
osThreadId long
3514
virtual boolean
false
allocated ulong: bytes
32
startTime long: millis
358754233729
thread Thread
group ThreadGroup
name string
main
parent ThreadGroup
name string
system
parent ThreadGroup
null
javaName string
map-output-dispatcher-1
javaThreadId long
1098
osName string
map-output-dispatcher-1
osThreadId long
3839
virtual boolean
false

ExceptionStatistics

default profiling startTime duration stackTrace 11 17 21 25 26 27

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/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:

            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 (IllegalStateException ise) {
            throw ise;
        } 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);
        }

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;
}

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
375767182126
throwables long
2241450
stackTrace StackTrace
null
startTime long: millis
431710123567
throwables long
2206125
stackTrace StackTrace
null
startTime long: millis
486552769285
throwables long
2240570

Java Development Kit

X509Certificate

startTime duration stackTrace 11 17 21 25 26 27

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/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();

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/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/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")

Configuration enabled stackTrace
default false true
profiling false true

Field Type Description
algorithm string Signature Algorithm
serialNumber string Serial Number
subject string Subject
issuer string Issuer
keyType string Key Type
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
21.0.10.0.1
name string
sun/security/jca
type FrameType
Interpreted
truncated boolean
false
startTime long: millis
453595826840
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
21.0.10.0.1
name string
sun/security/jca
type FrameType
Interpreted
truncated boolean
true
startTime long: millis
436845268136
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
21.0.10.0.1
name string
sun/security/jca
type FrameType
Interpreted
truncated boolean
true
startTime long: millis
341017285024
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 27

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/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;
}

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/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;

Configuration enabled stackTrace
default false true
profiling false true

Field Type Description
peerHost string Peer Host
peerPort int Peer Port
protocolVersion string Protocol Version
cipherSuite string Cipher Suite
certificateId long: certificateId Certificate Id Peer Certificate Id

SecurityPropertyModification

startTime duration stackTrace 11 17 21 25 26 27

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/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;
}

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/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/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;
}

Configuration enabled stackTrace
default false true
profiling false true

Field Type Description
key string Key
value string Value

X509Validation

startTime duration stackTrace 11 17 21 25 26 27

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/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;
}

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/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;
}

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

Operating System

OSInformation

default profiling startTime duration end of every chunk 11 17 21 25 26 27

Category: Operating System

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(VirtualizationInformation) {
  EventVirtualizationInformation event;
  event.set_name(JfrOSInterface::virtualization_name());
  event.commit();
}

TRACE_REQUEST_FUNC(ModuleRequire) {

Configuration enabled period
default true beginChunk
profiling true beginChunk

Field Type Description
osVersion string OS Version

Examples 3
osVersion string
DISTRIB_ID=Ubuntu DISTRIB_RELEASE=24.04 DISTRIB_CODENAME=noble DISTRIB_DESCRIPTION="Ubuntu 24.04.3 LTS" uname: Linux 6.14.0-1017-azure #17~24.04.1-Ubuntu SMP Mon Dec 1 20:10:50 UTC 2025 x86_64 libc: glibc 2.39 NPTL 2.39
startTime long: millis
392282853283
osVersion string
DISTRIB_ID=Ubuntu DISTRIB_RELEASE=24.04 DISTRIB_CODENAME=noble DISTRIB_DESCRIPTION="Ubuntu 24.04.3 LTS" uname: Linux 6.14.0-1017-azure #17~24.04.1-Ubuntu SMP Mon Dec 1 20:10:50 UTC 2025 x86_64 libc: glibc 2.39 NPTL 2.39
startTime long: millis
457857594806
osVersion string
DISTRIB_ID=Ubuntu DISTRIB_RELEASE=24.04 DISTRIB_CODENAME=noble DISTRIB_DESCRIPTION="Ubuntu 24.04.3 LTS" uname: Linux 6.14.0-1017-azure #17~24.04.1-Ubuntu SMP Mon Dec 1 20:10:50 UTC 2025 x86_64 libc: glibc 2.39 NPTL 2.39
startTime long: millis
369389008839

VirtualizationInformation

default profiling startTime duration end of every chunk 11 17 21 25 26 27

Category: Operating System

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(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(VirtualizationInformation) {
  EventVirtualizationInformation event;
  event.set_name(JfrOSInterface::virtualization_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
name string Name

Examples 3
name string
Hyper-V virtualization
startTime long: millis
476532703928
name string
Hyper-V virtualization
startTime long: millis
466046127462
name string
Hyper-V virtualization
startTime long: millis
329808622761

InitialEnvironmentVariable

default profiling startTime end of every chunk 11 17 21 25 26 27

Category: Operating System

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:

  } else if (vrt == PowerFullPartitionMode) {
    return "Power full partition";
  }

  return "No virtualization detected";
}

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_NDK
startTime long: millis
378265316802
value string
/usr/local/lib/android/sdk/ndk/27.3.13750724
key string
ANDROID_NDK_LATEST_HOME
startTime long: millis
300591002710
value string
/usr/local/lib/android/sdk/ndk/29.0.14206865
key string
GITHUB_REF
startTime long: millis
358740859335
value string
refs/heads/main

SystemProcess

default profiling startTime duration end of every chunk 11 17 21 25 26 27

Category: Operating System

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

CPUInformation

default profiling startTime duration end of every chunk 11 17 21 25 26 27

Category: Operating System / Processor

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
16
cpu string
AMD Unknown x86 (HT) SSE SSE2 SSE3 SSSE3 SSE4.1 SSE4.2 SSE4A AMD64
description string
Brand: AMD EPYC 7763 64-Core Processor , Vendor: AuthenticAMD Family: Unknown x86 (0x19), Model: <unknown> (0x1), Stepping: 0x1 Ext. family: 0xa, Ext. model: 0x0, Type: 0x0, Signature: 0x00a00f11 Features: ebx: 0x00100800, ecx: 0xfeda3203, edx: 0x178bfbff Ext. features: eax: 0x00a00f1
hwThreads uint
4
sockets uint
1
startTime long: millis
429295173989
cores uint
16
cpu string
AMD Unknown x86 (HT) SSE SSE2 SSE3 SSSE3 SSE4.1 SSE4.2 SSE4A AMD64
description string
Brand: AMD EPYC 7763 64-Core Processor , Vendor: AuthenticAMD Family: Unknown x86 (0x19), Model: <unknown> (0x1), Stepping: 0x1 Ext. family: 0xa, Ext. model: 0x0, Type: 0x0, Signature: 0x00a00f11 Features: ebx: 0x01100800, ecx: 0xfeda3203, edx: 0x178bfbff Ext. features: eax: 0x00a00f1
hwThreads uint
4
sockets uint
1
startTime long: millis
452705630721
cores uint
16
cpu string
AMD Unknown x86 (HT) SSE SSE2 SSE3 SSSE3 SSE4.1 SSE4.2 SSE4A AMD64
description string
Brand: AMD EPYC 7763 64-Core Processor , Vendor: AuthenticAMD Family: Unknown x86 (0x19), Model: <unknown> (0x1), Stepping: 0x1 Ext. family: 0xa, Ext. model: 0x0, Type: 0x0, Signature: 0x00a00f11 Features: ebx: 0x02100800, ecx: 0xfeda3203, edx: 0x178bfbff Ext. features: eax: 0x00a00f1
hwThreads uint
4
sockets uint
1
startTime long: millis
366131367281

CPUTimeStampCounter

default profiling startTime duration end of every chunk 11 17 21 25 26 27

Category: Operating System / Processor

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
true
fastTimeEnabled boolean
false
fastTimeFrequency long: hertz
1000000000
osFrequency long: hertz
1000000000
startTime long: millis
415356329629
fastTimeAutoEnabled boolean
true
fastTimeEnabled boolean
false
fastTimeFrequency long: hertz
1000000000
osFrequency long: hertz
1000000000
startTime long: millis
457857617448
fastTimeAutoEnabled boolean
true
fastTimeEnabled boolean
false
fastTimeFrequency long: hertz
1000000000
osFrequency long: hertz
1000000000
startTime long: millis
329808639012

CPULoad

default profiling startTime duration every chunk 11 17 21 25 26 27

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
0.0056872037
jvmUser float: percentage
0.40142182
machineTotal float: percentage
0.407109
startTime long: millis
310706175777
jvmSystem float: percentage
0.012468828
jvmUser float: percentage
0.3042394
machineTotal float: percentage
0.31670824
startTime long: millis
436752531441
jvmSystem float: percentage
0.003960396
jvmUser float: percentage
0.5683168
machineTotal float: percentage
0.57227725
startTime long: millis
443692160527

ThreadCPULoad

default profiling startTime duration eventThread every chunk 11 17 21 25 26 27

Category: Operating System / Processor

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_JFR_PERIODIC_JFRTHREADCPULOADEVENT_HPP
#define SHARE_JFR_PERIODIC_JFRTHREADCPULOADEVENT_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_JFR_PERIODIC_JFRTHREADCPULOADEVENT_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
333064932862
system float: percentage
0.0066719675
user float: percentage
0.21628906
startTime long: millis
419285869179
system float: percentage
7.823617E-6
user float: percentage
0.0
startTime long: millis
415011640321
system float: percentage
2.4320838E-5
user float: percentage
0.0

ThreadContextSwitchRate

default profiling startTime duration every chunk 11 17 21 25 26 27

Category: Operating System / Processor

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
375768614990
switchRate float: hertz
4368.228
startTime long: millis
371550434833
switchRate float: hertz
2361.2092
startTime long: millis
473505576921
switchRate float: hertz
3224.8538

NetworkUtilization

default profiling startTime every chunk 11 17 21 25 26 27

Category: Operating System / Network

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
enP109s1
readRate long: bits-per-second
1928
startTime long: millis
467550097710
writeRate long: bits-per-second
34664
networkInterface NetworkInterfaceName
enP50190s1
readRate long: bits-per-second
1232
startTime long: millis
359259636929
writeRate long: bits-per-second
35080
networkInterface NetworkInterfaceName
eth0
readRate long: bits-per-second
5808
startTime long: millis
473505187334
writeRate long: bits-per-second
13240

PhysicalMemory

default profiling startTime duration every chunk 11 17 21 25 26 27

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
446399594564
totalSize ulong: bytes
16767234048
usedSize ulong: bytes
4015656960
startTime long: millis
495864414721
totalSize ulong: bytes
16767234048
usedSize ulong: bytes
6402269184
startTime long: millis
313294771441
totalSize ulong: bytes
16767234048
usedSize ulong: bytes
3913154560

Types

CalleeMethod

Field Type Description
type string Class
name string Method Name
descriptor string Method Descriptor

Examples 3
descriptor string
(Ljava/lang/Throwable$PrintStreamOrWriter;)V
name string
printStackTrace
type string
java/lang/Throwable
descriptor string
()Ljava/lang/String;
name string
trim
type string
java/lang/String
descriptor string
()J
name string
gap
type string
scala/collection/immutable/Range

Class

Java Class

Field Type Description
classLoader ClassLoader Class Loader
name Symbol Name
package Package Package
modifiers int Access Modifiers

ClassLoader

Java Class Loader

Field Type Description
type Class Type
name Symbol Name

CodeBlobType

Code Blob Type

Field Type Description
type string Type

Examples 3
CodeHeap 'profiled nmethods'
CodeHeap 'non-nmethods'
CodeHeap 'non-nmethods'

CompilerPhaseType

Compiler Phase Type

Field Type Description
phase string Phase

CopyFailed

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

Field Type Description
origin string Origin

Examples 3
Default
Default
Default

FrameType

Frame type

Field Type Description
description string Description

Examples 3
Native
JIT compiled
Inlined

G1EvacuationStatistics

Appearing in: G1GC

Missing in: ParallelGC, SerialGC, ShenandoahGC, ZGC

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
3249040
directAllocated ulong: bytes
368368
failureUsed ulong: bytes
0
failureWaste ulong: bytes
0
gcId uint
935
regionEndWaste ulong: bytes
0
regionsRefilled uint: bytes
2
undoWaste ulong: bytes
0
used ulong: bytes
3072736
wasted ulong: bytes
1240
allocated ulong: bytes
0
directAllocated ulong: bytes
0
failureUsed ulong: bytes
0
failureWaste ulong: bytes
0
gcId uint
864
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

Field Type Description
type string Type

Examples 1
Free

G1YCType

Appearing in: G1GC

Missing in: ParallelGC, SerialGC, ShenandoahGC, ZGC

G1 YC Type

Field Type Description
type string Type

Examples 1
Prepare Mixed

GCCause

GC Cause

Field Type Description
cause string Cause

Examples 3
Heap Inspection Initiated GC
G1 Humongous Allocation
System.gc()

GCName

GC Name

Field Type Description
name string Name

Examples 3
ParallelScavenge
G1Old
G1New

GCThresholdUpdater

GC Threshold Updater

Field Type Description
updater string Updater

Examples 3
compute_new_size
compute_new_size
compute_new_size

GCWhen

GC When

Field Type Description
when string When

Examples 3
After GC
After GC
Before GC

InflateCause

Inflation Cause

Field Type Description
cause string Cause

MetadataType

Metadata Type

Field Type Description
type string Type

Examples 3
Class
Class
Class

MetaspaceObjectType

Metaspace Object Type

Field Type Description
type string Type

MetaspaceSizes

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
571342848
reserved ulong: bytes
603979776
used ulong: bytes
569426080
committed ulong: bytes
659423232
reserved ulong: bytes
1677721600
used ulong: bytes
655592528
committed ulong: bytes
88080384
reserved ulong: bytes
1073741824
used ulong: bytes
86166448

Method

Java Method

Field Type Description
type Class Type
name Symbol Name
descriptor Symbol Descriptor
modifiers int Access Modifiers
hidden boolean Hidden

Module

Module

Field Type Description
name Symbol Name
version Symbol Version
location Symbol Location
classLoader ClassLoader Class Loader

NarrowOopMode

Narrow Oop Mode

Field Type Description
mode string Mode

Examples 3
Zero based
Zero based
Zero based

NetworkInterfaceName

Network Interface

Field Type Description
networkInterface string Network Interface Network Interface Name

Examples 3
eth0
enP50190s1
enP109s1

ObjectSpace

Appearing in: ParallelGC

Missing in: G1GC, SerialGC, ShenandoahGC, ZGC

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
31992053760
size ulong: bytes
1824522240
start ulong: address
30167531520
used ulong: bytes
208967640
end ulong: address
33926152192
size ulong: bytes
963641344
start ulong: address
32962510848
used ulong: bytes
0
end ulong: address
33964949504
size ulong: bytes
38797312
start ulong: address
33926152192
used ulong: bytes
0

OldObject

Appearing in: G1GC, ParallelGC, SerialGC, ZGC

Missing in: ShenandoahGC

Old Object

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
31801977400
description string
null
referrer Reference
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
24
name string
java/util/concurrent/locks/AbstractQueuedSynchronizer$ConditionNode
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.10.0.1
name string
java/util/concurrent/locks
address ulong: address
30399620296
description string
null
referrer Reference
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1040
name string
[Ljava/util/concurrent/ConcurrentHashMap$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
21.0.10.0.1
name string
java/util/concurrent
address ulong: address
30375479640
description string
null
referrer Reference
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
24
name string
jdk/internal/jimage/ImageReader$Directory
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
21.0.10.0.1
name string
jdk/internal/jimage

OldObjectArray

Old Object Array

Field Type Description
size int Array Size Size of array
index int Index Index in the array

OldObjectField

Old Object Field

Field Type Description
name string Field Name of field
modifiers short Field Modifiers Field modifiers

OldObjectGcRoot

Appearing in: G1GC, ParallelGC, SerialGC, ZGC

Missing in: ShenandoahGC

GC Root

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

Field Type Description
system string System

OldObjectRootType

GC Root Type

Field Type Description
type string Type

Package

Package

Field Type Description
name Symbol Name
module Module Module
exported boolean Exported

Reference

Appearing in: G1GC, ParallelGC, SerialGC, ZGC

Missing in: ShenandoahGC

Reference

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

Field Type Description
type string Type

Examples 3
Weak reference
Soft reference
Final reference

ShenandoahHeapRegionState

Appearing in: ShenandoahGC

Missing in: G1GC, ParallelGC, SerialGC, ZGC

Shenandoah Heap Region State

Field Type Description
state string State

Examples 2
Trash
Empty Committed

StackFrame

Field Type Description
method Method Java Method
lineNumber int Line Number
bytecodeIndex int Bytecode Index
type FrameType Frame Type

Examples 3
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
21.0.10.0.1
name string
java/lang
type FrameType
Inlined
bytecodeIndex int
0
lineNumber int
-1
method Method
descriptor string
(ZJ)V
hidden boolean
false
modifiers int
257
name string
park
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
17
name string
jdk/internal/misc/Unsafe
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
21.0.10.0.1
name string
jdk/internal/misc
type FrameType
Native
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
21.0.10.0.1
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
21.0.10.0.1
name string
java/net
location string
null
name string
null
version string
null
name string
net/jpountz/lz4
type FrameType
JIT compiled

StackTrace

Stacktrace

Field Type Description
truncated boolean Truncated
frames array StackFrame struct Stack Frames

Examples 3
frames StackFrame
bytecodeIndex int
0
lineNumber int
-1
method Method
descriptor string
(ZJ)V
hidden boolean
false
modifiers int
257
name string
park
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
17
name string
jdk/internal/misc/Unsafe
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
21.0.10.0.1
name string
jdk/internal/misc
type FrameType
Native
truncated boolean
false
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
21.0.10.0.1
name string
java/lang
type FrameType
Inlined
truncated boolean
true
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
21.0.10.0.1
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
21.0.10.0.1
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

Symbol

Symbol

Field Type Description
string string String

Thread

Thread

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

Field Type Description
parent ThreadGroup Parent
name string Name

Examples 3
name string
main
parent ThreadGroup
name string
system
parent ThreadGroup
null
null
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

Field Type Description
type string Type

Examples 3
ClassLoaderStatsOperation
JFRSafepointWrite
GC_HeapInspection

VirtualSpace

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
31167873024
committedSize ulong: bytes
1000341504
reservedEnd ulong: address
34359738368
reservedSize ulong: bytes
4192206848
start ulong: address
30167531520
committedEnd ulong: address
31992053760
committedSize ulong: bytes
1824522240
reservedEnd ulong: address
32962510848
reservedSize ulong: bytes
2794979328
start ulong: address
30167531520
committedEnd ulong: address
32966180864
committedSize ulong: bytes
2798649344
reservedEnd ulong: address
34359738368
reservedSize ulong: bytes
4192206848
start ulong: address
30167531520

ZStatisticsCounterType

Appearing in: ZGC

Missing in: G1GC, ParallelGC, SerialGC, ShenandoahGC

Z Statistics Counter

Field Type Description
counter string Counter

Examples 1
Allocation Rate

ZStatisticsSamplerType

Appearing in: ZGC

Missing in: G1GC, ParallelGC, SerialGC, ShenandoahGC

Z Statistics Sampler

Field Type Description
sampler string Sampler

Examples 1
Concurrent References Process

XML Content Types

address

Annotation: jdk.jfr.MemoryAddress

Examples 3
30167531520
30313910736
30484201472

bits-per-second

Annotation: jdk.jfr.DataAmount(BITS), jdk.jfr.Frequency

Examples 3
5808
1232
35080

bytes

Annotation: jdk.jfr.DataAmount(BYTES)

Examples 3
0
32784
586864

bytes-per-second

Appearing in: G1GC

Missing in: ParallelGC, SerialGC, ShenandoahGC, ZGC

Annotation: jdk.jfr.DataAmount(BYTES), jdk.jfr.Frequency

Examples 2
2.5270621520287663E8
0.0

certificateId

Annotation: jdk.jfr.events.CertificateId

Examples 3
3045411335
3045411335
3045411335

epochmillis

Annotation: jdk.jfr.Timestamp(MILLISECONDS_SINCE_EPOCH)

Examples 3
1773535714974
-9223372036854775808
1773535714518

hertz

Annotation: jdk.jfr.Frequency

Examples 3
4368.228
1000000000
1000000000

millis

Annotation: jdk.jfr.Timespan(MILLISECONDS)

Examples 3
301527641499
301191208897
300747095969

nanos

Annotation: jdk.jfr.Timespan(NANOSECONDS)

Examples 3
99999930
-9223372036854775808
-9223372036854775808

percentage

Annotation: jdk.jfr.Percentage

Examples 3
0.40142182
0.0056872037
0.407109

tickspan

Annotation: jdk.jfr.Timespan(TICKS)

Examples 3
4464971
334854367
1724382

tickstamp

Annotation: jdk.jfr.Timestamp(TICKS)

XML Types

Class

Parameter Type const Klass*
Field Type const Klass*
Java Type java.lang.Class
Examples 3
null
null
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
21.0.10.0.1
name string
java/io

ClassLoader

Parameter Type const ClassLoaderData*
Field Type const ClassLoaderData*
Examples 3
name string
bootstrap
type Class
null
name string
bootstrap
type Class
null
name string
bootstrap
type Class
null

Method

Parameter Type const Method*
Field Type const Method*
Examples 3
descriptor string
(ZJ)V
hidden boolean
false
modifiers int
257
name string
park
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
17
name string
jdk/internal/misc/Unsafe
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
21.0.10.0.1
name string
jdk/internal/misc
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
21.0.10.0.1
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
21.0.10.0.1
name string
java/net
location string
null
name string
null
version string
null
name string
net/jpountz/lz4
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
21.0.10.0.1
name string
java/lang

Module

Parameter Type const ModuleEntry*
Field Type const ModuleEntry*
Examples 3
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.10.0.1
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.10.0.1
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.10.0.1

Package

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
21.0.10.0.1
name string
java/io
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.10.0.1
name string
java/lang
null

Thread

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
Executor task launch worker for task 8.0 in stage 18.0 (TID 115)
javaThreadId long
1162
osName string
Executor task launch worker for task 8.0 in stage 18.0 (TID 115)
osThreadId long
3855
virtual boolean
false
group ThreadGroup
name string
main
parent ThreadGroup
name string
system
parent ThreadGroup
null
javaName string
JFR Periodic Tasks
javaThreadId long
22
osName string
JFR Periodic Tasks
osThreadId long
2414
virtual boolean
false
group ThreadGroup
name string
main
parent ThreadGroup
name string
system
parent ThreadGroup
null
javaName string
rpc-boss-3-1
javaThreadId long
1113
osName string
rpc-boss-3-1
osThreadId long
3799
virtual boolean
false

Ticks

Appearing in: G1GC, ParallelGC, SerialGC, ZGC

Missing in: ShenandoahGC

Parameter Type const Ticks&
Field Type Ticks
Java Type long
Content Type tickstamp
Examples 3
465818007771
456523887189
360738078449

Tickspan

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
1.5625
2.0
2.0

float

Parameter Type float
Field Type float
Java Type float
Examples 3
7.815155
7.8353696
2.799173

int

Parameter Type s4
Field Type s4
Java Type int
Examples 3

long

Parameter Type s8
Field Type s8
Java Type long
Examples 3
1113
3799
2241450

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/io/EOFException
null
bootstrap

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
864
151
874

ulong

unsigned

Parameter Type u8
Field Type u8
Java Type long
Examples 3

ushort

unsigned

Parameter Type u2
Field Type u2
Java Type short
Examples 3