src/share/vm/utilities/workgroup.hpp

rev 6345 : 8040803: G1: Concurrent mark hangs when mark stack overflows
Reviewed-by: TDB

@@ -360,19 +360,21 @@
 protected:
   Monitor _monitor;
   uint     _n_workers;
   uint     _n_completed;
   bool    _should_reset;
+  bool    _aborted;
 
   Monitor* monitor()        { return &_monitor; }
   uint     n_workers()      { return _n_workers; }
   uint     n_completed()    { return _n_completed; }
   bool     should_reset()   { return _should_reset; }
+  bool     aborted()        { return _aborted; }
 
   void     zero_completed() { _n_completed = 0; }
   void     inc_completed()  { _n_completed++; }
-
+  void     set_aborted()    { _aborted = true; }
   void     set_should_reset(bool v) { _should_reset = v; }
 
 public:
   WorkGangBarrierSync();
   WorkGangBarrierSync(uint n_workers, const char* name);

@@ -381,12 +383,18 @@
   // Must be called before any of the workers start running.
   void set_n_workers(uint n_workers);
 
   // Enter the barrier. A worker that enters the barrier will
   // not be allowed to leave until all other threads have
-  // also entered the barrier.
-  void enter();
+  // also entered the barrier or the barrier is aborted.
+  // Returns false if the barrier was aborted.
+  bool enter();
+
+  // Aborts the barrier and wakes up any threads waiting for
+  // the barrier to complete. The barrier will remain in the
+  // aborted state until the next call to set_n_workers().
+  void abort();
 };
 
 // A class to manage claiming of subtasks within a group of tasks.  The
 // subtasks will be identified by integer indices, usually elements of an
 // enumeration type.