src/share/vm/gc/cms/concurrentMarkSweepGeneration.cpp

rev 10742 : Make fields used in lock-free algorithms volatile

@@ -3002,11 +3002,11 @@
   CMSCollector* _collector;
   uint          _n_workers;       // requested/desired # workers
   bool          _result;
   CompactibleFreeListSpace*  _cms_space;
   char          _pad_front[64];   // padding to ...
-  HeapWord*     _global_finger;   // ... avoid sharing cache line
+  HeapWord* volatile _global_finger;   // ... avoid sharing cache line
   char          _pad_back[64];
   HeapWord*     _restart_addr;
 
   //  Exposed here for yielding support
   Mutex* const _bit_map_lock;

@@ -3040,11 +3040,11 @@
 
   OopTaskQueueSet* task_queues()  { return _task_queues; }
 
   OopTaskQueue* work_queue(int i) { return task_queues()->queue(i); }
 
-  HeapWord** global_finger_addr() { return &_global_finger; }
+  HeapWord* volatile* global_finger_addr() { return &_global_finger; }
 
   CMSConcMarkingTerminator* terminator() { return &_term; }
 
   virtual void set_for_termination(uint active_workers) {
     terminator()->reset_for_reuse(active_workers);

@@ -6523,11 +6523,11 @@
     _mut->clear_range(mr);
   }
 
   // Note: the local finger doesn't advance while we drain
   // the stack below, but the global finger sure can and will.
-  HeapWord** gfa = _task->global_finger_addr();
+  HeapWord* volatile* gfa = _task->global_finger_addr();
   ParPushOrMarkClosure pushOrMarkClosure(_collector,
                                          _span, _bit_map,
                                          _work_queue,
                                          _overflow_stack,
                                          _finger,

@@ -6690,11 +6690,11 @@
                                            MemRegion span,
                                            CMSBitMap* bit_map,
                                            OopTaskQueue* work_queue,
                                            CMSMarkStack*  overflow_stack,
                                            HeapWord* finger,
-                                           HeapWord** global_finger_addr,
+                                           HeapWord* volatile* global_finger_addr,
                                            ParMarkFromRootsClosure* parent) :
   MetadataAwareOopClosure(collector->ref_processor()),
   _collector(collector),
   _whole_span(collector->_span),
   _span(span),