8257967: JFR: Events for loaded agents

Reviewed-by: dholmes, sspitsyn

Author: Markus Grönlund

make/hotspot/lib/JvmFeatures.gmk

@@ -88,7 +88,7 @@ ifneq ($(call check-jvm-feature, jvmti), true)
       jvmtiImpl.cpp jvmtiManageCapabilities.cpp jvmtiRawMonitor.cpp jvmtiUtil.cpp jvmtiTrace.cpp \
       jvmtiCodeBlobEvents.cpp jvmtiEnv.cpp jvmtiRedefineClasses.cpp jvmtiEnvBase.cpp jvmtiEnvThreadState.cpp \
       jvmtiTagMap.cpp jvmtiEventController.cpp evmCompat.cpp jvmtiEnter.xsl jvmtiExport.cpp \
-      jvmtiClassFileReconstituter.cpp jvmtiTagMapTable.cpp
+      jvmtiClassFileReconstituter.cpp jvmtiTagMapTable.cpp jvmtiAgent.cpp jvmtiAgentList.cpp
 endif
 
 ifneq ($(call check-jvm-feature, jvmci), true)

src/hotspot/share/jfr/metadata/metadata.xml

@@ -1172,6 +1172,25 @@
     <Field type="ulong" name="totalFinalizersRun" label="Finalizers Run" description="Total number of finalizers run since JVM start" />
   </Event>
 
+  <Event name="JavaAgent" category="Java Virtual Machine, Diagnostics" label="Java Agent" description="A Java programming language agent making use of the java.lang.instrument package for instrumenting programs running on the JVM"
+    thread="false" startTime="false" period="endChunk" stackTrace="false">
+    <Field type="string" name="name" label="Name" />
+    <Field type="string" name="options" label="Options" />
+    <Field type="boolean" name="dynamic" label="Dynamic" description="If the agent attached to the JVM dynamically during runtime, i.e. not at startup" />
+    <Field type="Ticks" name="initializationTime" label="Initialization Time" description="The time the JVM initialized the agent" />
+    <Field type="Tickspan" name="initializationDuration" label="Initialization Duration" description="The duration of executing the initialization method, either premain or agentmain" />
+  </Event>
+
+  <Event name="NativeAgent" category="Java Virtual Machine, Diagnostics" label="Native Agent" description="A native programming language agent making use of the JVMTI interface used by development, profiling and monitoring tools"
+    thread="false" startTime="false" period="endChunk" stackTrace="false">
+    <Field type="string" name="name" label="Name" />
+    <Field type="string" name="options" label="Options" />
+    <Field type="boolean" name="dynamic" label="Dynamic" description="If the library attached to the JVM dynamically during runtime, i.e. not at startup" />
+    <Field type="Ticks" name="initializationTime" label="Initialization Time" description="The time the JVM initialized the agent" />
+    <Field type="Tickspan" name="initializationDuration" label="Initialization Duration" description="The duration of executing the JVMTI VMInit event callback. If no VMInit callback is specified, the duration is 0. For a dynamically loaded agent, it is the duration of executing the call to Agent_OnAttach." />
+    <Field type="string" name="path" label="Path" description="The path of the library" />
+  </Event>
+
   <Type name="DeoptimizationReason" label="Deoptimization Reason">
     <Field type="string" name="reason" label="Reason" />
   </Type>

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

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2012, 2022, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2012, 2023, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -52,6 +52,7 @@
 #include "memory/heapInspection.hpp"
 #include "memory/resourceArea.hpp"
 #include "oops/oop.inline.hpp"
+#include "prims/jvmtiAgentList.hpp"
 #include "runtime/arguments.hpp"
 #include "runtime/flags/jvmFlag.hpp"
 #include "runtime/globals.hpp"
@@ -269,6 +270,43 @@ TRACE_REQUEST_FUNC(SystemProcess) {
   }
 }
 
+template <typename AgentEvent>
+static void send_agent_event(AgentEvent& event, const JvmtiAgent* agent) {
+  event.set_name(agent->name());
+  event.set_options(agent->options());
+  event.set_dynamic(agent->is_dynamic());
+  event.set_initializationTime(agent->initialization_time());
+  event.set_initializationDuration(agent->initialization_duration());
+  event.commit();
+}
+
+TRACE_REQUEST_FUNC(JavaAgent) {
+  const JvmtiAgentList::Iterator it =JvmtiAgentList::java_agents();
+  while (it.has_next()) {
+    const JvmtiAgent* agent = it.next();
+    assert(agent->is_jplis(), "invariant");
+    EventJavaAgent event;
+    send_agent_event(event, agent);
+  }
+}
+
+static void send_native_agent_events(const JvmtiAgentList::Iterator& it) {
+  while (it.has_next()) {
+    const JvmtiAgent* agent = it.next();
+    assert(!agent->is_jplis(), "invariant");
+    EventNativeAgent event;
+    event.set_path(agent->os_lib_path());
+    send_agent_event(event, agent);
+  }
+}
+
+TRACE_REQUEST_FUNC(NativeAgent) {
+  const JvmtiAgentList::Iterator native_agents_it = JvmtiAgentList::native_agents();
+  send_native_agent_events(native_agents_it);
+  const JvmtiAgentList::Iterator xrun_agents_it = JvmtiAgentList::xrun_agents();
+  send_native_agent_events(xrun_agents_it);
+}
+
 TRACE_REQUEST_FUNC(ThreadContextSwitchRate) {
   double rate = 0.0;
   int ret_val = OS_ERR;