[Backport] 8225797: OldObjectSample event creates unexpected amount o…

…f checkpoint data

Summary:

Test Plan: jdk/jfr

Reviewed-by: yuleil

Issue: dragonwell-project/dragonwell8#112

src/share/vm/jfr/instrumentation/jfrEventClassTransformer.cpp

@@ -1461,7 +1461,7 @@ static void copy_method_trace_flags(const InstanceKlass* the_original_klass, con
     assert(new_method != NULL, "invariant");
     assert(new_method->name() == old_method->name(), "invariant");
     assert(new_method->signature() == old_method->signature(), "invariant");
-    *new_method->trace_flags_addr() = old_method->trace_flags();
+    new_method->set_trace_flags(old_method->trace_flags());
     assert(new_method->trace_flags() == old_method->trace_flags(), "invariant");
   }
 }

src/share/vm/jfr/jfr.cpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2019, 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
@@ -92,7 +92,9 @@ void Jfr::on_vm_shutdown(bool exception_handler) {
 }
 
 void Jfr::weak_oops_do(BoolObjectClosure* is_alive, OopClosure* f) {
-  LeakProfiler::oops_do(is_alive, f);
+  if (LeakProfiler::is_running()) {
+    LeakProfiler::oops_do(is_alive, f);
+  }
 }
 
 void Jfr::weak_oops_do(OopClosure* f) {

src/share/vm/jfr/leakprofiler/chains/edgeStore.cpp

@@ -55,18 +55,23 @@ bool EdgeStore::is_empty() const {
   return !_edges->has_entries();
 }
 
-void EdgeStore::assign_id(EdgeEntry* entry) {
+void EdgeStore::on_link(EdgeEntry* entry) {
   assert(entry != NULL, "invariant");
   assert(entry->id() == 0, "invariant");
   entry->set_id(++_edge_id_counter);
 }
 
-bool EdgeStore::equals(const Edge& query, uintptr_t hash, const EdgeEntry* entry) {
+bool EdgeStore::on_equals(uintptr_t hash, const EdgeEntry* entry) {
   assert(entry != NULL, "invariant");
   assert(entry->hash() == hash, "invariant");
   return true;
 }
 
+void EdgeStore::on_unlink(EdgeEntry* entry) {
+  assert(entry != NULL, "invariant");
+  // nothing
+}
+
 #ifdef ASSERT
 bool EdgeStore::contains(const oop* reference) const {
   return get(reference) != NULL;
@@ -75,22 +80,21 @@ bool EdgeStore::contains(const oop* reference) const {
 
 StoredEdge* EdgeStore::get(const oop* reference) const {
   assert(reference != NULL, "invariant");
-  const StoredEdge e(NULL, reference);
-  EdgeEntry* const entry = _edges->lookup_only(e, (uintptr_t)reference);
+  EdgeEntry* const entry = _edges->lookup_only((uintptr_t)reference);
   return entry != NULL ? entry->literal_addr() : NULL;
 }
 
 StoredEdge* EdgeStore::put(const oop* reference) {
   assert(reference != NULL, "invariant");
   const StoredEdge e(NULL, reference);
-  assert(NULL == _edges->lookup_only(e, (uintptr_t)reference), "invariant");
-  EdgeEntry& entry = _edges->put(e, (uintptr_t)reference);
+  assert(NULL == _edges->lookup_only((uintptr_t)reference), "invariant");
+  EdgeEntry& entry = _edges->put((uintptr_t)reference, e);
   return entry.literal_addr();
 }
 
 traceid EdgeStore::get_id(const Edge* edge) const {
   assert(edge != NULL, "invariant");
-  EdgeEntry* const entry = _edges->lookup_only(*edge, (uintptr_t)edge->reference());
+  EdgeEntry* const entry = _edges->lookup_only((uintptr_t)edge->reference());
   assert(entry != NULL, "invariant");
   return entry->id();
 }

src/share/vm/jfr/leakprofiler/chains/edgeStore.hpp

@@ -58,7 +58,7 @@ class StoredEdge : public Edge {
 };
 
 class EdgeStore : public CHeapObj<mtTracing> {
-  typedef HashTableHost<StoredEdge, traceid, Entry, EdgeStore> EdgeHashTable;
+  typedef HashTableHost<StoredEdge, traceid, JfrHashtableEntry, EdgeStore> EdgeHashTable;
   typedef EdgeHashTable::HashEntry EdgeEntry;
   template <typename,
             typename,
@@ -74,8 +74,9 @@ class EdgeStore : public CHeapObj<mtTracing> {
   EdgeHashTable* _edges;
 
   // Hash table callbacks
-  void assign_id(EdgeEntry* entry);
-  bool equals(const Edge& query, uintptr_t hash, const EdgeEntry* entry);
+  void on_link(EdgeEntry* entry);
+  bool on_equals(uintptr_t hash, const EdgeEntry* entry);
+  void on_unlink(EdgeEntry* entry);
 
   StoredEdge* get(const oop* reference) const;
   StoredEdge* put(const oop* reference);

src/share/vm/jfr/leakprofiler/chains/pathToGcRootsOperation.cpp

@@ -42,7 +42,6 @@
 #include "jfr/leakprofiler/sampling/objectSampler.hpp"
 #include "jfr/leakprofiler/utilities/granularTimer.hpp"
 #include "memory/universe.hpp"
-#include "oops/markOop.hpp"
 #include "oops/oop.inline.hpp"
 #include "runtime/safepoint.hpp"
 #include "utilities/globalDefinitions.hpp"
@@ -101,7 +100,7 @@ void PathToGcRootsOperation::doit() {
   // Save the original markWord for the potential leak objects,
   // to be restored on function exit
   ObjectSampleMarker marker;
-  if (ObjectSampleCheckpoint::mark(_sampler, marker, _emit_all) == 0) {
+  if (ObjectSampleCheckpoint::save_mark_words(_sampler, marker, _emit_all) == 0) {
     // no valid samples to process
     return;
   }