src/hotspot/share/gc/parallel/psCompactionManager.hpp

@@ -26,10 +26,11 @@
 #define SHARE_GC_PARALLEL_PSCOMPACTIONMANAGER_HPP
 
 #include "gc/shared/taskqueue.hpp"
 #include "memory/allocation.hpp"
 #include "utilities/stack.hpp"
+#include "psParallelCompact.hpp"
 
 class MutableSpace;
 class PSOldGen;
 class ParCompactionManager;
 class ObjectStartArray;

@@ -75,18 +76,27 @@
   static PSOldGen*              _old_gen;
 
 private:
   OverflowTaskQueue<oop, mtGC>        _marking_stack;
   ObjArrayTaskQueue             _objarray_stack;
+  size_t                        _shadow_record;
 
   // Is there a way to reuse the _marking_stack for the
   // saving empty regions?  For now just create a different
   // type of TaskQueue.
   RegionTaskQueue              _region_stack;
 
   static ParMarkBitMap* _mark_bitmap;
 
+  // The shadow region array, we use it in a LIFO fashion, so
+  // that we can reuse shadow regions for better data locality
+  // and utilization
+  static GrowableArray<size_t>* _shadow_region_array;
+
+  // This Monitor provides mutual exclusive access of _shadow_region_array
+  static Monitor*               _shadow_region_monitor;
+
   Action _action;
 
   HeapWord* _last_query_beg;
   oop _last_query_obj;
   size_t _last_query_ret;

@@ -107,10 +117,18 @@
   void stack_push(oop obj);
   // Do not implement an equivalent stack_pop.  Deal with the
   // marking stack and overflow stack directly.
 
  public:
+  static size_t  acquire_shadow_region(PSParallelCompact::RegionData* region_ptr);
+  static void    release_shadow_region(size_t shadow_region);
+  static void    enqueue_shadow_region(size_t shadow_region);
+  static void    dequeue_shadow_region();
+  inline size_t  shadow_record() { return _shadow_record; }
+  inline void    set_shadow_record(size_t record) { _shadow_record = record; }
+  inline size_t  next_shadow_record(size_t workers) { _shadow_record += workers; return shadow_record(); }
+
   void reset_bitmap_query_cache() {
     _last_query_beg = NULL;
     _last_query_obj = NULL;
     _last_query_ret = 0;
   }