8238236: Add JFR class redefinition events

Reviewed-by: mgronlun

Author: egahlin

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

@@ -101,6 +101,22 @@
     <Field type="ClassLoader" name="definingClassLoader" label="Defining Class Loader" />
   </Event>
 
+  <Event name="ClassRedefinition" category="Java Virtual Machine, Class Loading" label="Class Redefinition" thread="false" stackTrace="false" startTime="false">
+    <Field type="Class" name="redefinedClass" label="Redefined Class" />
+    <Field type="int" name="classModificationCount" label="Class Modification Count" description="The number of times the class has changed"/>
+    <Field type="ulong" name="redefinitionId" label="Class Redefinition Id" relation="ClassRedefinitionId"/>
+  </Event>
+
+  <Event name="RedefineClasses" category="Java Virtual Machine, Class Loading" label="Redefine Classes" thread="true" stackTrace="true">
+    <Field type="int" name="classCount" label="Class Count" />
+    <Field type="ulong" name="redefinitionId" label="Class Redefinition Id" relation="ClassRedefinitionId" />
+  </Event>
+
+  <Event name="RetransformClasses" category="Java Virtual Machine, Class Loading" label="Retransform Classes" thread="true" stackTrace="true">
+    <Field type="int" name="classCount" label="Class Count"/>
+    <Field type="ulong" name="redefinitionId" label="Class Redefinition Id" relation="ClassRedefinitionId" />
+  </Event>
+
   <Event name="ClassUnload" category="Java Virtual Machine, Class Loading" label="Class Unload" thread="true" startTime="false">
     <Field type="Class" name="unloadedClass" label="Unloaded Class" />
     <Field type="ClassLoader" name="definingClassLoader" label="Defining Class Loader" />
@@ -1236,7 +1252,8 @@
   <Relation name="CompileId" />
   <Relation name="SweepId"/>
   <Relation name="FlushId"/>
-
+  <Relation name="ClassRedefinitionId"/>
+  
   <XmlType name="Package" parameterType="const PackageEntry*" fieldType="const PackageEntry*"/>
   <XmlType name="Class" javaType="java.lang.Class" parameterType="const Klass*" fieldType="const Klass*"/>
   <XmlType name="Module"  parameterType="const ModuleEntry*" fieldType="const ModuleEntry*"/>

src/hotspot/share/prims/jvmtiEnv.cpp

@@ -31,6 +31,7 @@
 #include "classfile/vmSymbols.hpp"
 #include "interpreter/bytecodeStream.hpp"
 #include "interpreter/interpreter.hpp"
+#include "jfr/jfrEvents.hpp"
 #include "jvmtifiles/jvmtiEnv.hpp"
 #include "logging/log.hpp"
 #include "logging/logConfiguration.hpp"
@@ -446,9 +447,16 @@ JvmtiEnv::RetransformClasses(jint class_count, const jclass* classes) {
     }
     class_definitions[index].klass              = jcls;
   }
+  EventRetransformClasses event;
   VM_RedefineClasses op(class_count, class_definitions, jvmti_class_load_kind_retransform);
   VMThread::execute(&op);
-  return (op.check_error());
+  jvmtiError error = op.check_error();
+  if (error == JVMTI_ERROR_NONE) {
+    event.set_classCount(class_count);
+    event.set_redefinitionId(op.id());
+    event.commit();
+  }
+  return error;
 } /* end RetransformClasses */
 
 
@@ -457,9 +465,16 @@ JvmtiEnv::RetransformClasses(jint class_count, const jclass* classes) {
 jvmtiError
 JvmtiEnv::RedefineClasses(jint class_count, const jvmtiClassDefinition* class_definitions) {
 //TODO: add locking
+  EventRedefineClasses event;
   VM_RedefineClasses op(class_count, class_definitions, jvmti_class_load_kind_redefine);
   VMThread::execute(&op);
-  return (op.check_error());
+  jvmtiError error = op.check_error();
+  if (error == JVMTI_ERROR_NONE) {
+    event.set_classCount(class_count);
+    event.set_redefinitionId(op.id());
+    event.commit();
+  }
+  return error;
 } /* end RedefineClasses */
 
 

src/hotspot/share/prims/jvmtiRedefineClasses.cpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2003, 2019, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2003, 2020, 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
@@ -35,6 +35,7 @@
 #include "compiler/compileBroker.hpp"
 #include "interpreter/oopMapCache.hpp"
 #include "interpreter/rewriter.hpp"
+#include "jfr/jfrEvents.hpp"
 #include "logging/logStream.hpp"
 #include "memory/metadataFactory.hpp"
 #include "memory/metaspaceShared.hpp"
@@ -51,6 +52,7 @@
 #include "prims/jvmtiThreadState.inline.hpp"
 #include "prims/resolvedMethodTable.hpp"
 #include "prims/methodComparator.hpp"
+#include "runtime/atomic.hpp"
 #include "runtime/deoptimization.hpp"
 #include "runtime/handles.inline.hpp"
 #include "runtime/jniHandles.inline.hpp"
@@ -70,7 +72,7 @@ int       VM_RedefineClasses::_deleted_methods_length  = 0;
 int       VM_RedefineClasses::_added_methods_length    = 0;
 bool      VM_RedefineClasses::_has_redefined_Object = false;
 bool      VM_RedefineClasses::_has_null_class_loader = false;
-
+u8        VM_RedefineClasses::_id_counter = 0;
 
 VM_RedefineClasses::VM_RedefineClasses(jint class_count,
                                        const jvmtiClassDefinition *class_defs,
@@ -83,6 +85,7 @@ VM_RedefineClasses::VM_RedefineClasses(jint class_count,
   _the_class = NULL;
   _has_redefined_Object = false;
   _has_null_class_loader = false;
+  _id = next_id();
 }
 
 static inline InstanceKlass* get_ik(jclass def) {
@@ -4294,6 +4297,15 @@ void VM_RedefineClasses::redefine_single_class(jclass the_jclass,
   }
 
   increment_class_counter((InstanceKlass *)the_class, THREAD);
+
+  if (EventClassRedefinition::is_enabled()) {
+    EventClassRedefinition event;
+    event.set_classModificationCount(java_lang_Class::classRedefinedCount(the_class->java_mirror()));
+    event.set_redefinedClass(the_class);
+    event.set_redefinitionId(_id);
+    event.commit();
+  }
+
   {
     ResourceMark rm(THREAD);
     // increment the classRedefinedCount field in the_class and in any
@@ -4307,6 +4319,7 @@ void VM_RedefineClasses::redefine_single_class(jclass the_jclass,
 
   }
   _timer_rsc_phase2.stop();
+
 } // end redefine_single_class()
 
 
@@ -4393,6 +4406,16 @@ void VM_RedefineClasses::CheckClass::do_klass(Klass* k) {
   }
 }
 
+u8 VM_RedefineClasses::next_id() {
+  while (true) {
+    u8 id = _id_counter;
+    u8 next_id = id + 1;
+    u8 result = Atomic::cmpxchg(&_id_counter, id, next_id);
+    if (result == id) {
+      return next_id;
+    }
+  }
+}
 
 void VM_RedefineClasses::dump_methods() {
   int j;

src/hotspot/share/prims/jvmtiRedefineClasses.hpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2003, 2019, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2003, 2020, 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
@@ -351,6 +351,9 @@ class VM_RedefineClasses: public VM_Operation {
   static bool            _has_redefined_Object;
   static bool            _has_null_class_loader;
 
+  // Used by JFR to group class redefininition events together.
+  static u8              _id_counter;
+
   // The instance fields are used to pass information from
   // doit_prologue() to doit() and doit_epilogue().
   Klass*                      _the_class;
@@ -388,6 +391,9 @@ class VM_RedefineClasses: public VM_Operation {
   elapsedTimer  _timer_rsc_phase2;
   elapsedTimer  _timer_vm_op_prologue;
 
+  // Redefinition id used by JFR
+  u8 _id;
+
   // These routines are roughly in call order unless otherwise noted.
 
   // Load the caller's new class definition(s) into _scratch_classes.
@@ -503,6 +509,8 @@ class VM_RedefineClasses: public VM_Operation {
   void lock_classes();
   void unlock_classes();
 
+  u8 next_id();
+
   static void dump_methods();
 
   // Check that there are no old or obsolete methods
@@ -535,6 +543,7 @@ class VM_RedefineClasses: public VM_Operation {
 
   bool allow_nested_vm_operations() const        { return true; }
   jvmtiError check_error()                       { return _res; }
+  u8 id()                                        { return _id; }
 
   // Modifiable test must be shared between IsModifiableClass query
   // and redefine implementation

src/jdk.jfr/share/conf/jfr/default.jfc

@@ -124,6 +124,22 @@
       <setting name="stackTrace">true</setting>
     </event>
 
+    <event name="jdk.RedefineClasses">
+      <setting name="enabled">true</setting>
+      <setting name="stackTrace">true</setting>
+      <setting name="threshold">0 ms</setting>
+    </event>
+
+    <event name="jdk.RetransformClasses">
+      <setting name="enabled">true</setting>
+      <setting name="stackTrace">true</setting>
+      <setting name="threshold">0 ms</setting>
+    </event>
+
+    <event name="jdk.ClassRedefinition">
+      <setting name="enabled" control="class-loading-enabled">true</setting>
+    </event>
+
     <event name="jdk.ClassUnload">
       <setting name="enabled" control="class-loading-enabled">false</setting>
     </event>

src/jdk.jfr/share/conf/jfr/profile.jfc

@@ -124,6 +124,22 @@
       <setting name="stackTrace">true</setting>
     </event>
 
+    <event name="jdk.RedefineClasses">
+      <setting name="enabled">true</setting>
+      <setting name="stackTrace">true</setting>
+      <setting name="threshold">0 ms</setting>
+    </event>
+
+    <event name="jdk.RetransformClasses">
+      <setting name="enabled">true</setting>
+      <setting name="stackTrace">true</setting>
+      <setting name="threshold">0 ms</setting>
+    </event>
+
+    <event name="jdk.ClassRedefinition">
+      <setting name="enabled" control="class-loading-enabled">true</setting>
+    </event>
+
     <event name="jdk.ClassUnload">
       <setting name="enabled" control="class-loading-enabled">false</setting>
     </event>

test/lib/jdk/test/lib/jfr/EventNames.java

@@ -87,6 +87,10 @@ public class EventNames {
     public final static String PlaceholderTableStatistics = PREFIX + "PlaceholderTableStatistics";
     public final static String LoaderConstraintsTableStatistics = PREFIX + "LoaderConstraintsTableStatistics";
     public final static String ProtectionDomainCacheTableStatistics = PREFIX + "ProtectionDomainCacheTableStatistics";
+    public static final String RedefineClasses = PREFIX + "RedefineClasses";
+    public static final String RetransformClasses = PREFIX + "RetransformClasses";
+    public static final String ClassRedefinition = PREFIX + "ClassRedefinition";
+
     // This event is hard to test
     public final static String ReservedStackActivation = PREFIX + "ReservedStackActivation";
 

test/lib/jdk/test/lib/jfr/Events.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2013, 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2013, 2020, 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
@@ -48,7 +48,10 @@
 import jdk.test.lib.Asserts;
 import jdk.jfr.consumer.RecordedClass;
 import jdk.jfr.consumer.RecordedEvent;
+import jdk.jfr.consumer.RecordedFrame;
+import jdk.jfr.consumer.RecordedMethod;
 import jdk.jfr.consumer.RecordedObject;
+import jdk.jfr.consumer.RecordedStackTrace;
 import jdk.jfr.consumer.RecordedThread;
 import jdk.jfr.consumer.RecordedThreadGroup;
 
@@ -363,4 +366,21 @@ private static boolean containsEvent(List<RecordedEvent> events, String name) {
         }
         return false;
     }
+
+    public static void assertFrame(RecordedEvent event, Class<?> expectedClass, String expectedMethodName) {
+        RecordedStackTrace stackTrace = event.getStackTrace();
+        Asserts.assertNotNull(stackTrace, "Missing stack trace");
+        for (RecordedFrame frame : stackTrace.getFrames()) {
+            if (frame.isJavaFrame()) {
+                RecordedMethod method = frame.getMethod();
+                RecordedClass type = method.getType();
+                if (expectedClass.getName().equals(type.getName())) {
+                    if (expectedMethodName.equals(method.getName())) {
+                        return;
+                    }
+                }
+            }
+        }
+        Asserts.fail("Expected " + expectedClass.getName() + "::"+ expectedMethodName + " in stack trace");
+    }
 }

test/lib/jdk/test/lib/util/JavaAgentBuilder.java

@@ -73,6 +73,8 @@ public static void build(String agentClass, String agentJar) throws IOException
         Manifest mf = new Manifest();
         Attributes attrs = mf.getMainAttributes();
         attrs.put(Attributes.Name.MANIFEST_VERSION, "1.0");
+        attrs.putValue("Can-Redefine-Classes", "true");
+        attrs.putValue("Can-Retransform-Classes", "true");
         attrs.putValue("Premain-Class", agentClass);
         attrs.putValue("Agent-Class", agentClass);