src/share/vm/jfr/leakprofiler/sampling/objectSampler.hpp

rev 9055 : 8214542: JFR: Old Object Sample event slow on a deep heap in debug builds
Reviewed-by: egahlin, rwestberg

@@ -26,11 +26,14 @@
 #define SHARE_VM_LEAKPROFILER_SAMPLING_OBJECTSAMPLER_HPP
 
 #include "memory/allocation.hpp"
 #include "jfr/utilities/jfrTime.hpp"
 
+typedef u8 traceid;
+
 class BoolObjectClosure;
+class JfrStackTrace;
 class OopClosure;
 class ObjectSample;
 class ObjectSampler;
 class SampleList;
 class SamplePriorityQueue;

@@ -38,36 +41,51 @@
 
 // Class reponsible for holding samples and
 // making sure the samples are evenly distributed as
 // new entries are added and removed.
 class ObjectSampler : public CHeapObj<mtTracing> {
+  friend class EventEmitter;
+  friend class JfrRecorderService;
   friend class LeakProfiler;
-  friend class ObjectSampleCheckpoint;
   friend class StartOperation;
   friend class StopOperation;
-  friend class EmitEventOperation;
+  friend class ObjectSampleCheckpoint;
+  friend class WriteObjectSampleStacktrace;
  private:
   SamplePriorityQueue* _priority_queue;
   SampleList* _list;
   JfrTicks _last_sweep;
   size_t _total_allocated;
   size_t _threshold;
   size_t _size;
-  volatile int _tryLock;
   bool _dead_samples;
 
+  // Lifecycle
   explicit ObjectSampler(size_t size);
   ~ObjectSampler();
-
-  void add(HeapWord* object, size_t size, JavaThread* thread);
-  void remove_dead(ObjectSample* sample);
+  static bool create(size_t size);
+  static bool is_created();
+  static ObjectSampler* sampler();
+  static void destroy();
+
+  // For operations that require exclusive access (non-safepoint)
+  static ObjectSampler* acquire();
+  static void release();
+
+  // Stacktrace
+  static void fill_stacktrace(JfrStackTrace* stacktrace, JavaThread* thread);
+  traceid stacktrace_id(const JfrStackTrace* stacktrace, JavaThread* thread);
+
+  // Sampling
+  static void sample(HeapWord* object, size_t size, JavaThread* thread);
+  void add(HeapWord* object, size_t size, traceid thread_id, JfrStackTrace* stacktrace, JavaThread* thread);
   void scavenge();
+  void remove_dead(ObjectSample* sample);
 
   // Called by GC
-  void oops_do(BoolObjectClosure* is_alive, OopClosure* f);
+  static void oops_do(BoolObjectClosure* is_alive, OopClosure* f);
 
- public:
   const ObjectSample* item_at(int index) const;
   ObjectSample* item_at(int index);
   int item_count() const;
   const ObjectSample* first() const;
   const ObjectSample* last() const;