[heap] Provide ObjectMarking with marking transitions

src/heap/mark-compact-inl.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_INL_H_
 #define V8_HEAP_MARK_COMPACT_INL_H_
 
 #include "src/heap/mark-compact.h"
 #include "src/heap/remembered-set.h"
 #include "src/isolate.h"
 
 namespace v8 {
 namespace internal {
 
 void MarkCompactCollector::PushBlack(HeapObject* obj) {
   DCHECK(Marking::IsBlack(ObjectMarking::MarkBitFrom(obj)));

[Hannes Payer (out of office), 2017/01/18 14:43:35]

That would also short cut the double accessors: ObjectMarking::IsBlack(obj)

[Michael Lippautz, 2017/01/18 15:58:07]

Done.

-  if (marking_deque()->Push(obj)) {
-    MemoryChunk::IncrementLiveBytes(obj, obj->Size());
-  } else {
-    MarkBit mark_bit = ObjectMarking::MarkBitFrom(obj);
-    Marking::BlackToGrey(mark_bit);
+  if (!marking_deque()->Push(obj)) {
+    ObjectMarking::BlackToGrey(obj);
   }
 }
 
 
 void MarkCompactCollector::UnshiftBlack(HeapObject* obj) {
   DCHECK(Marking::IsBlack(ObjectMarking::MarkBitFrom(obj)));
   if (!marking_deque()->Unshift(obj)) {
-    MemoryChunk::IncrementLiveBytes(obj, -obj->Size());
-    MarkBit mark_bit = ObjectMarking::MarkBitFrom(obj);
-    Marking::BlackToGrey(mark_bit);
+    ObjectMarking::BlackToGrey(obj);
   }
 }
 
 
 void MarkCompactCollector::MarkObject(HeapObject* obj, MarkBit mark_bit) {
   DCHECK(ObjectMarking::MarkBitFrom(obj) == mark_bit);
   if (Marking::IsWhite(mark_bit)) {
-    Marking::WhiteToBlack(mark_bit);
-    DCHECK(obj->GetIsolate()->heap()->Contains(obj));
+    ObjectMarking::WhiteToBlack(obj);
     PushBlack(obj);
   }
 }
 
 
 void MarkCompactCollector::SetMark(HeapObject* obj, MarkBit mark_bit) {
-  DCHECK(Marking::IsWhite(mark_bit));
+  DCHECK(Marking::IsWhite(ObjectMarking::MarkBitFrom(obj)));
   DCHECK(ObjectMarking::MarkBitFrom(obj) == mark_bit);
-  Marking::WhiteToBlack(mark_bit);
-  MemoryChunk::IncrementLiveBytes(obj, obj->Size());
+  ObjectMarking::WhiteToBlack(obj);
 }
 
 
 bool MarkCompactCollector::IsMarked(Object* obj) {
   DCHECK(obj->IsHeapObject());
   HeapObject* heap_object = HeapObject::cast(obj);
   return Marking::IsBlackOrGrey(ObjectMarking::MarkBitFrom(heap_object));
 }
 
 
@@ skipping 159 matching lines @@
     }
     if (object != nullptr) return object;
   }
   return nullptr;
 }
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_HEAP_MARK_COMPACT_INL_H_