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

*** 48,57 ****
--- 48,59 ----
  ParCompactionManager::ObjArrayTaskQueueSet*
    ParCompactionManager::_objarray_queues = NULL;
  ObjectStartArray*    ParCompactionManager::_start_array = NULL;
  ParMarkBitMap*       ParCompactionManager::_mark_bitmap = NULL;
  RegionTaskQueueSet*  ParCompactionManager::_region_array = NULL;
+ GrowableArray<size_t >* ParCompactionManager::_shadow_region_array = NULL;
+ Monitor*                ParCompactionManager::_shadow_region_monitor = NULL;
  
  ParCompactionManager::ParCompactionManager() :
      _action(CopyAndUpdate) {
  
    ParallelScavengeHeap* heap = ParallelScavengeHeap::heap();
*** 98,107 ****
--- 100,116 ----
    _manager_array[parallel_gc_threads] = new ParCompactionManager();
    guarantee(_manager_array[parallel_gc_threads] != NULL,
      "Could not create ParCompactionManager");
    assert(ParallelScavengeHeap::heap()->workers().total_workers() != 0,
      "Not initialized?");
+ 
+   _shadow_region_array = new (ResourceObj::C_HEAP, mtInternal) GrowableArray<size_t >(10, true);
+   guarantee(_shadow_region_array != NULL, "Could not allocate shadow_region_array");
+ 
+   _shadow_region_monitor = new Monitor(Mutex::barrier, "CompactionManager monitor",
+                                        Mutex::_allow_vm_block_flag, Monitor::_safepoint_check_never);
+   guarantee(_shadow_region_monitor != NULL, "Could not allocate shadow_region_monitor");
  }
  
  void ParCompactionManager::reset_all_bitmap_query_caches() {
    uint parallel_gc_threads = ParallelScavengeHeap::heap()->workers().total_workers();
    for (uint i=0; i<=parallel_gc_threads; i++) {
*** 162,166 ****
--- 171,204 ----
      while (region_stack()->pop_local(region_index)) {
        PSParallelCompact::fill_and_update_region(this, region_index);
      }
    } while (!region_stack()->is_empty());
  }
+ 
+ size_t ParCompactionManager::acquire_shadow_region(PSParallelCompact::RegionData* region_ptr) {
+   while (true) {
+     MutexLocker ml(_shadow_region_monitor, Mutex::_no_safepoint_check_flag);
+     if (_shadow_region_array->is_empty()) {
+       // The corresponding heap region may be available now,
+       // so we don't need to acquire a shadow region anymore,
+       // and we return 0 to indicate this case
+       if (region_ptr->claimed()) {
+         return 0;
+       }
+     } else {
+       return _shadow_region_array->pop();
+     }
+   }
+ }
+ 
+ void ParCompactionManager::release_shadow_region(size_t shadow_region) {
+   MutexLocker ml(_shadow_region_monitor, Mutex::_no_safepoint_check_flag);
+   _shadow_region_array->append(shadow_region);
+ }
+ 
+ void ParCompactionManager::enqueue_shadow_region(size_t shadow_region) {
+   _shadow_region_array->append(shadow_region);
+ }
+ 
+ void ParCompactionManager::dequeue_shadow_region() {
+   _shadow_region_array->clear();
+ }
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