Replace slots buffer with remembered set.

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"
 #include "src/heap/store-buffer.h"
 
 namespace v8 {
 namespace internal {
 
 // Callback function, returns whether an object is alive. The heap size
 // of the object is returned in size. It optionally updates the offset
 // to the first live object in the page (only used for old and map objects).
 typedef bool (*IsAliveFunction)(HeapObject* obj, int* size, int* offset);
 
 // Callback function to mark an object in a given heap.
 typedef void (*MarkObjectFunction)(Heap* heap, HeapObject* object);
 
 // Forward declarations.
 class CodeFlusher;
 class MarkCompactCollector;
 class MarkingVisitor;
 class RootMarkingVisitor;
-class SlotsBuffer;
-class SlotsBufferAllocator;
-
+class LocalSlotsBuffer;
 
 class Marking : public AllStatic {
  public:
   INLINE(static MarkBit MarkBitFrom(Address addr)) {
     MemoryChunk* p = MemoryChunk::FromAddress(addr);
     return p->markbits()->MarkBitFromIndex(p->AddressToMarkbitIndex(addr));
   }
 
   INLINE(static MarkBit MarkBitFrom(HeapObject* obj)) {
     return MarkBitFrom(reinterpret_cast<Address>(obj));
@@ skipping 347 matching lines @@
   INLINE(static bool ShouldSkipEvacuationSlotRecording(Object* host)) {
     return Page::FromAddress(reinterpret_cast<Address>(host))
         ->ShouldSkipEvacuationSlotRecording();
   }
 
   INLINE(static bool IsOnEvacuationCandidate(Object* obj)) {
     return Page::FromAddress(reinterpret_cast<Address>(obj))
         ->IsEvacuationCandidate();
   }
 
-  void RecordRelocSlot(RelocInfo* rinfo, Object* target);
-  void RecordCodeEntrySlot(HeapObject* object, Address slot, Code* target);
+  void RecordRelocSlot(Code* host, RelocInfo* rinfo, Object* target);
+  void RecordCodeEntrySlot(HeapObject* host, 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,
-                     SlotsBuffer** evacuation_slots_buffer,
-                     LocalStoreBuffer* local_store_buffer);
+                     LocalSlotsBuffer* old_to_old_slots,
+                     LocalSlotsBuffer* old_to_new_slots);
 
   void InvalidateCode(Code* code);
 
   void ClearMarkbits();
 
   bool is_compacting() const { return compacting_; }
 
   MarkingParity marking_parity() { return marking_parity_; }
 
   // Concurrent and parallel sweeping support. If required_freed_bytes was set
@@ skipping 55 matching lines @@
 
   void EnsureMarkingDequeIsCommitted(size_t max_size);
   void EnsureMarkingDequeIsReserved();
 
   void InitializeMarkingDeque();
 
   // The following four methods can just be called after marking, when the
   // whole transitive closure is known. They must be called before sweeping
   // when mark bits are still intact.
   bool IsSlotInBlackObject(Page* p, Address slot, HeapObject** out_object);
-  bool IsSlotInBlackObjectSlow(Page* p, Address slot);
+  HeapObject* FindBlackObjectBySlotSlow(Address slot);
   bool IsSlotInLiveObject(Address slot);
-  void VerifyIsSlotInLiveObject(Address slot, HeapObject* object);
 
   // Removes all the slots in the slot buffers that are within the given
   // address range.
   void RemoveObjectSlots(Address start_slot, Address end_slot);
 
   //
   // Free lists filled by sweeper and consumed by corresponding spaces
   // (including compaction spaces).
   //
   base::SmartPointer<FreeList>& free_list_old_space() {
@@ skipping 13 matching lines @@
   class EvacuateVisitorBase;
   class Evacuator;
   class HeapObjectVisitor;
   class SweeperTask;
 
   typedef std::vector<Page*> SweepingList;
 
   explicit MarkCompactCollector(Heap* heap);
 
   bool WillBeDeoptimized(Code* code);
-  void EvictPopularEvacuationCandidate(Page* page);
-  void ClearInvalidStoreAndSlotsBufferEntries();
+  void ClearInvalidRememberedSetSlots();
 
   void StartSweeperThreads();
 
   void ComputeEvacuationHeuristics(int area_size,
                                    int* target_fragmentation_percent,
                                    int* max_evacuated_bytes);
 
 #ifdef DEBUG
   enum CollectorState {
     IDLE,
     PREPARE_GC,
     MARK_LIVE_OBJECTS,
     SWEEP_SPACES,
     ENCODE_FORWARDING_ADDRESSES,
     UPDATE_POINTERS,
     RELOCATE_OBJECTS
   };
 
   // The current stage of the collector.
   CollectorState state_;
 #endif
 
   MarkingParity marking_parity_;
 
   bool was_marked_incrementally_;
 
   bool evacuation_;
 
-  SlotsBufferAllocator* slots_buffer_allocator_;
-
-  SlotsBuffer* migration_slots_buffer_;
-
   // 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 133 matching lines @@
   inline SweepingList& sweeping_list(Space* space);
 
   // 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();
 
   void EvacuateNewSpacePrologue();
   void EvacuateNewSpaceEpilogue();
 
-  void AddEvacuationSlotsBufferSynchronized(
-      SlotsBuffer* evacuation_slots_buffer);
-
   void EvacuatePagesInParallel();
 
   // The number of parallel compaction tasks, including the main thread.
   int NumberOfParallelCompactionTasks(int pages, intptr_t live_bytes);
 
   void StartParallelCompaction(Evacuator** evacuators, int len);
   void WaitUntilCompactionCompleted(Evacuator** evacuators, int len);
 
   void EvacuateNewSpaceAndCandidates();
 
@@ skipping 15 matching lines @@
   // Starts sweeping of a space by contributing on the main thread and setting
   // up other pages for sweeping.
   void StartSweepSpace(PagedSpace* space);
 
   // Finalizes the parallel sweeping phase. Marks all the pages that were
   // swept in parallel.
   void ParallelSweepSpacesComplete();
 
   // Updates store buffer and slot buffer for a pointer in a migrating object.
   void RecordMigratedSlot(Object* value, Address slot,
-                          SlotsBuffer** evacuation_slots_buffer,
-                          LocalStoreBuffer* local_store_buffer);
-
-  // Adds the code entry slot to the slots buffer.
-  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,
-                                    SlotsBuffer** evacuation_slots_buffer);
+                          LocalSlotsBuffer* old_to_old_slots,
+                          LocalSlotsBuffer* old_to_new_slots);
 
 #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_;
   List<NewSpacePage*> newspace_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_;
 
   SweepingList sweeping_list_old_space_;
   SweepingList sweeping_list_code_space_;
   SweepingList sweeping_list_map_space_;
 
   // True if we are collecting slots to perform evacuation from evacuation
   // candidates.
@@ skipping 97 matching lines @@
  private:
   MarkCompactCollector* collector_;
 };
 
 
 const char* AllocationSpaceName(AllocationSpace space);
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_HEAP_MARK_COMPACT_H_