src/share/vm/gc/g1/g1ConcurrentMark.hpp

@@ -350,12 +350,21 @@
   // point when all the tasks complete their work. It is really used
   // to determine the points between the end of concurrent marking and
   // time of remark.
   volatile bool           _concurrent_marking_in_progress;
 
-  // Keep track of whether we have started concurrent phase or not.
-  bool                    _concurrent_phase_started;
+  // There would be a race between ConcurrentMarkThread and VMThread(ConcurrentMark::abort())
+  // to call ConcurrentGCTimer::register_gc_concurrent_end().
+  // And this variable is used to keep track of concurrent phase.
+  volatile uint           _concurrent_phase_status;
+  // Concurrent phase is not yet started.
+  static const uint       ConcPhaseNotStarted = 0;
+  // Concurrent phase is started.
+  static const uint       ConcPhaseStarted = 1;
+  // Caller thread of ConcurrentGCTimer::register_gc_concurrent_end() is ending concurrent phase.
+  // So other thread should wait until the status to be changed to ConcPhaseNotStarted.
+  static const uint       ConcPhaseStopping = 2;
 
   // All of these times are in ms
   NumberSeq _init_times;
   NumberSeq _remark_times;
   NumberSeq _remark_mark_times;

@@ -483,10 +492,13 @@
   intptr_t _heap_bottom_card_num;
 
   // Set to true when initialization is complete
   bool _completed_initialization;
 
+  // end_timer, true to end gc timer after ending concurrent phase.
+  void register_concurrent_phase_end_common(bool end_timer);
+
 public:
   // Manipulation of the global mark stack.
   // The push and pop operations are used by tasks for transfers
   // between task-local queues and the global mark stack, and use
   // locking for concurrency safety.

@@ -518,10 +530,12 @@
     _concurrent_marking_in_progress = false;
   }
 
   void register_concurrent_phase_start(const char* title);
   void register_concurrent_phase_end();
+  // Ends both concurrent phase and timer.
+  void register_concurrent_gc_end();
 
   void update_accum_task_vtime(int i, double vtime) {
     _accum_task_vtime[i] += vtime;
   }