Use just one marking deque.

src/heap/incremental-marking.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_INCREMENTAL_MARKING_H_
 #define V8_HEAP_INCREMENTAL_MARKING_H_
 
 
 #include "src/execution.h"
 #include "src/heap/mark-compact.h"
@@ skipping 10 matching lines @@
   enum CompletionAction { GC_VIA_STACK_GUARD, NO_GC_VIA_STACK_GUARD };
 
   enum ForceMarkingAction { FORCE_MARKING, DO_NOT_FORCE_MARKING };
 
   enum ForceCompletionAction { FORCE_COMPLETION, DO_NOT_FORCE_COMPLETION };
 
   explicit IncrementalMarking(Heap* heap);
 
   static void Initialize();
 
-  void TearDown();
-
   State state() {
     DCHECK(state_ == STOPPED || FLAG_incremental_marking);
     return state_;
   }
 
   bool should_hurry() { return should_hurry_; }
   void set_should_hurry(bool val) { should_hurry_ = val; }
 
   inline bool IsStopped() { return state() == STOPPED; }
 
@@ skipping 94 matching lines @@
   inline void WhiteToGreyAndPush(HeapObject* obj, MarkBit mark_bit);
 
   inline void SetOldSpacePageFlags(MemoryChunk* chunk) {
     SetOldSpacePageFlags(chunk, IsMarking(), IsCompacting());
   }
 
   inline void SetNewSpacePageFlags(NewSpacePage* chunk) {
     SetNewSpacePageFlags(chunk, IsMarking());
   }
 
-  MarkingDeque* marking_deque() { return &marking_deque_; }
-
-  bool IsMarkingDequeEmpty() { return marking_deque_.IsEmpty(); }
-
   bool IsCompacting() { return IsMarking() && is_compacting_; }
 
   void ActivateGeneratedStub(Code* stub);
 
   void NotifyOfHighPromotionRate() {
     if (IsMarking()) {
       if (marking_speed_ < kFastMarking) {
         if (FLAG_trace_gc) {
           PrintPID(
               "Increasing marking speed to %d "
               "due to high promotion rate\n",
               static_cast<int>(kFastMarking));
         }
         marking_speed_ = kFastMarking;
       }
     }
   }
 
   void EnterNoMarkingScope() { no_marking_scope_depth_++; }
 
   void LeaveNoMarkingScope() { no_marking_scope_depth_--; }
 
-  void UncommitMarkingDeque();
-
   void NotifyIncompleteScanOfObject(int unscanned_bytes) {
     unscanned_bytes_of_large_object_ = unscanned_bytes;
   }
 
   void ClearIdleMarkingDelayCounter();
 
   bool IsIdleMarkingDelayCounterLimitReached();
 
  private:
   int64_t SpaceLeftInOldSpace();
@@ skipping 10 matching lines @@
 
   static void DeactivateIncrementalWriteBarrierForSpace(PagedSpace* space);
   static void DeactivateIncrementalWriteBarrierForSpace(NewSpace* space);
   void DeactivateIncrementalWriteBarrier();
 
   static void SetOldSpacePageFlags(MemoryChunk* chunk, bool is_marking,
                                    bool is_compacting);
 
   static void SetNewSpacePageFlags(NewSpacePage* chunk, bool is_marking);
 
-  void EnsureMarkingDequeIsCommitted();
-
   INLINE(void ProcessMarkingDeque());
 
   INLINE(intptr_t ProcessMarkingDeque(intptr_t bytes_to_process));
 
   INLINE(void VisitObject(Map* map, HeapObject* obj, int size));
 
   void IncrementIdleMarkingDelayCounter();
 
   Heap* heap_;
 
   State state_;
   bool is_compacting_;
 
-  base::VirtualMemory* marking_deque_memory_;
-  bool marking_deque_memory_committed_;
-  MarkingDeque marking_deque_;
-
   int steps_count_;
   int64_t old_generation_space_available_at_start_of_incremental_;
   int64_t old_generation_space_used_at_start_of_incremental_;
   int64_t bytes_rescanned_;
   bool should_hurry_;
   int marking_speed_;
   intptr_t bytes_scanned_;
   intptr_t allocated_;
   intptr_t write_barriers_invoked_since_last_step_;
   size_t idle_marking_delay_counter_;
 
   int no_marking_scope_depth_;
 
   int unscanned_bytes_of_large_object_;
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(IncrementalMarking);
 };
 }
 }  // namespace v8::internal
 
 #endif  // V8_HEAP_INCREMENTAL_MARKING_H_