[heap] Scalable slots buffer for parallel compaction.

src/heap/mark-compact.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_HEAP_MARK_COMPACT_H_
 #define V8_HEAP_MARK_COMPACT_H_
 
 #include "src/base/bits.h"
 #include "src/heap/spaces.h"
 
@@ skipping 409 matching lines @@
   void RecordCodeEntrySlot(HeapObject* object, Address slot, Code* target);
   void RecordCodeTargetPatch(Address pc, Code* target);
   INLINE(void RecordSlot(HeapObject* object, Object** slot, Object* target));
   INLINE(void ForceRecordSlot(HeapObject* object, Object** slot,
                               Object* target));
 
   void UpdateSlots(SlotsBuffer* buffer);
   void UpdateSlotsRecordedIn(SlotsBuffer* buffer);
 
   void MigrateObject(HeapObject* dst, HeapObject* src, int size,
-                     AllocationSpace to_old_space);
+                     AllocationSpace to_old_space,
+                     SlotsBuffer** evacuation_slots_buffer);
 
-  void MigrateObjectTagged(HeapObject* dst, HeapObject* src, int size);
-  void MigrateObjectMixed(HeapObject* dst, HeapObject* src, int size);
+  void MigrateObjectTagged(HeapObject* dst, HeapObject* src, int size,
+                           SlotsBuffer** evacuation_slots_buffer);
+  void MigrateObjectMixed(HeapObject* dst, HeapObject* src, int size,
+                          SlotsBuffer** evacuation_slots_buffer);
   void MigrateObjectRaw(HeapObject* dst, HeapObject* src, int size);
 
   bool TryPromoteObject(HeapObject* object, int object_size);
 
   void InvalidateCode(Code* code);
 
   void ClearMarkbits();
 
   bool is_compacting() const { return compacting_; }
 
@@ skipping 115 matching lines @@
 
   // Number of active compaction tasks (including main thread).
   intptr_t concurrent_compaction_tasks_active_;
 
   bool evacuation_;
 
   SlotsBufferAllocator* slots_buffer_allocator_;
 
   SlotsBuffer* migration_slots_buffer_;
 
-  base::Mutex migration_slots_buffer_mutex_;
-
   // Finishes GC, performs heap verification if enabled.
   void Finish();
 
   // -----------------------------------------------------------------------
   // Phase 1: Marking live objects.
   //
   //  Before: The heap has been prepared for garbage collection by
   //          MarkCompactCollector::Prepare() and is otherwise in its
   //          normal state.
   //
@@ skipping 128 matching lines @@
   // If we are not compacting the heap, we simply sweep the spaces except
   // for the large object space, clearing mark bits and adding unmarked
   // regions to each space's free list.
   void SweepSpaces();
 
   int DiscoverAndEvacuateBlackObjectsOnPage(NewSpace* new_space,
                                             NewSpacePage* p);
 
   void EvacuateNewSpace();
 
-  bool EvacuateLiveObjectsFromPage(Page* p, PagedSpace* target_space);
+  bool EvacuateLiveObjectsFromPage(Page* p, PagedSpace* target_space,
+                                   SlotsBuffer** evacuation_slots_buffer);
 
-  void EvacuatePages(CompactionSpaceCollection* compaction_spaces);
+  void AddEvacuationSlotsBufferSynchronized(
+      SlotsBuffer* evacuation_slots_buffer);
+
+  void EvacuatePages(CompactionSpaceCollection* compaction_spaces,
+                     SlotsBuffer** evacuation_slots_buffer);
+
   void EvacuatePagesInParallel();
 
   int NumberOfParallelCompactionTasks() {
     // TODO(hpayer, mlippautz): Figure out some logic to determine the number
     // of compaction tasks.
     return 1;
   }
 
   void WaitUntilCompactionCompleted();
 
   void EvacuateNewSpaceAndCandidates();
 
   void ReleaseEvacuationCandidates();
 
   // Moves the pages of the evacuation_candidates_ list to the end of their
   // corresponding space pages list.
   void MoveEvacuationCandidatesToEndOfPagesList();
 
   void SweepSpace(PagedSpace* space, SweeperType sweeper);
 
   // Finalizes the parallel sweeping phase. Marks all the pages that were
   // swept in parallel.
   void ParallelSweepSpacesComplete();
 
   void ParallelSweepSpaceComplete(PagedSpace* space);
 
   // Updates store buffer and slot buffer for a pointer in a migrating object.
-  void RecordMigratedSlot(Object* value, Address slot);
+  void RecordMigratedSlot(Object* value, Address slot,
+                          SlotsBuffer** evacuation_slots_buffer);
 
   // Adds the code entry slot to the slots buffer.
-  void RecordMigratedCodeEntrySlot(Address code_entry, Address code_entry_slot);
+  void RecordMigratedCodeEntrySlot(Address code_entry, Address code_entry_slot,
+                                   SlotsBuffer** evacuation_slots_buffer);
 
   // Adds the slot of a moved code object.
-  void RecordMigratedCodeObjectSlot(Address code_object);
+  void RecordMigratedCodeObjectSlot(Address code_object,
+                                    SlotsBuffer** evacuation_slots_buffer);
 
 #ifdef DEBUG
   friend class MarkObjectVisitor;
   static void VisitObject(HeapObject* obj);
 
   friend class UnmarkObjectVisitor;
   static void UnmarkObject(HeapObject* obj);
 #endif
 
   Heap* heap_;
   base::VirtualMemory* marking_deque_memory_;
   size_t marking_deque_memory_committed_;
   MarkingDeque marking_deque_;
   CodeFlusher* code_flusher_;
   bool have_code_to_deoptimize_;
 
   List<Page*> evacuation_candidates_;
 
+  // The evacuation_slots_buffers_ are used by the compaction threads.
+  // When a compaction task finishes, it uses
+  // AddEvacuationSlotsbufferSynchronized to adds its slots buffer to the
+  // evacuation_slots_buffers_ list using the evacuation_slots_buffers_mutex_
+  // lock.
+  base::Mutex evacuation_slots_buffers_mutex_;
+  List<SlotsBuffer*> evacuation_slots_buffers_;
+
   base::SmartPointer<FreeList> free_list_old_space_;
   base::SmartPointer<FreeList> free_list_code_space_;
   base::SmartPointer<FreeList> free_list_map_space_;
 
   friend class Heap;
 };
 
 
 class MarkBitCellIterator BASE_EMBEDDED {
  public:
@@ skipping 48 matching lines @@
  private:
   MarkCompactCollector* collector_;
 };
 
 
 const char* AllocationSpaceName(AllocationSpace space);
 }
 }  // namespace v8::internal
 
 #endif  // V8_HEAP_MARK_COMPACT_H_