[heap] Refactor marking deque.

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 <deque>
 
 #include "src/base/bits.h"
@@ skipping 35 matching lines @@
 
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(ObjectMarking);
 };
 
 // ----------------------------------------------------------------------------
 // Marking deque for tracing live objects.
 class MarkingDeque {
  public:
   MarkingDeque()
-      : array_(NULL),
+      : backing_store_(nullptr),
+        backing_store_committed_size_(0),
+        array_(nullptr),
         top_(0),
         bottom_(0),
         mask_(0),
         overflowed_(false),
         in_use_(false) {}
 
-  void Initialize(Address low, Address high);
-  void Uninitialize(bool aborting = false);
+  void SetUp();
+  void TearDown();
+
+  void StartUsing();
+  void StopUsing();
+  void Clear();
 
   inline bool IsFull() { return ((top_ + 1) & mask_) == bottom_; }
 
   inline bool IsEmpty() { return top_ == bottom_; }
 
   bool overflowed() const { return overflowed_; }
 
-  bool in_use() const { return in_use_; }
-
   void ClearOverflowed() { overflowed_ = false; }
 
   void SetOverflowed() { overflowed_ = true; }
 
   // Push the object on the marking stack if there is room, otherwise mark the
   // deque as overflowed and wait for a rescan of the heap.
   INLINE(bool Push(HeapObject* object)) {
     DCHECK(object->IsHeapObject());
     if (IsFull()) {
       SetOverflowed();
@@ skipping 27 matching lines @@
     }
   }
 
   HeapObject** array() { return array_; }
   int bottom() { return bottom_; }
   int top() { return top_; }
   int mask() { return mask_; }
   void set_top(int top) { top_ = top; }
 
  private:
+  static const size_t kMaxSize = 4 * MB;
+  static const size_t kMinSize = 256 * KB;
+
+  void EnsureCommitted();
+  void Uncommit();
+
+  base::VirtualMemory* backing_store_;
+  size_t backing_store_committed_size_;
   HeapObject** array_;
   // array_[(top - 1) & mask_] is the top element in the deque.  The Deque is
   // empty when top_ == bottom_.  It is full when top_ + 1 == bottom
   // (mod mask + 1).
   int top_;
   int bottom_;
   int mask_;
   bool overflowed_;
   bool in_use_;
 
@@ skipping 332 matching lines @@
   // Special case for processing weak references in a full collection. We need
   // to artificially keep AllocationSites alive for a time.
   void MarkAllocationSite(AllocationSite* site);
 
   // Mark objects in implicit references groups if their parent object
   // is marked.
   void MarkImplicitRefGroups(MarkObjectFunction mark_object);
 
   MarkingDeque* marking_deque() { return &marking_deque_; }
 
-  static const size_t kMaxMarkingDequeSize = 4 * MB;
-  static const size_t kMinMarkingDequeSize = 256 * KB;
-
-  void EnsureMarkingDequeIsCommittedAndInitialize(size_t max_size) {
-    if (!marking_deque()->in_use()) {
-      EnsureMarkingDequeIsCommitted(max_size);
-      InitializeMarkingDeque();
-    }
-  }
-
-  void EnsureMarkingDequeIsCommitted(size_t max_size);
-  void EnsureMarkingDequeIsReserved();
-
-  void InitializeMarkingDeque();
-
   Sweeper& sweeper() { return sweeper_; }
 
  private:
   class EvacuateNewSpacePageVisitor;
   class EvacuateNewSpaceVisitor;
   class EvacuateOldSpaceVisitor;
   class EvacuateRecordOnlyVisitor;
   class EvacuateVisitorBase;
   class HeapObjectVisitor;
   class ObjectStatsVisitor;
@@ skipping 203 matching lines @@
   bool evacuation_;
 
   // True if we are collecting slots to perform evacuation from evacuation
   // candidates.
   bool compacting_;
 
   bool black_allocation_;
 
   bool have_code_to_deoptimize_;
 
-  base::VirtualMemory* marking_deque_memory_;
-  size_t marking_deque_memory_committed_;
   MarkingDeque marking_deque_;
 
   CodeFlusher* code_flusher_;
 
   List<Page*> evacuation_candidates_;
   List<Page*> newspace_evacuation_candidates_;
 
   Sweeper sweeper_;
 
   friend class Heap;
@@ skipping 12 matching lines @@
 
  private:
   MarkCompactCollector* collector_;
 };
 
 V8_EXPORT_PRIVATE const char* AllocationSpaceName(AllocationSpace space);
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_HEAP_MARK_COMPACT_H_