Implement map collection for incremental marking.

src/mark-compact-inl.h

-// Copyright 2011 the V8 project authors. All rights reserved.
+// Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
 //       with the distribution.
@@ skipping 33 matching lines @@
 
 
 void MarkCompactCollector::SetFlags(int flags) {
   sweep_precisely_ = ((flags & Heap::kSweepPreciselyMask) != 0);
   reduce_memory_footprint_ = ((flags & Heap::kReduceMemoryFootprintMask) != 0);
   abort_incremental_marking_ =
       ((flags & Heap::kAbortIncrementalMarkingMask) != 0);
 }
 
 
+bool MarkCompactCollector::MarkObjectAndPush(HeapObject* obj) {
+  if (MarkObjectWithoutPush(obj)) {
+    marking_deque_.PushBlack(obj);
+    return true;
+  }
+  return false;
+}
+
+
 void MarkCompactCollector::MarkObject(HeapObject* obj, MarkBit mark_bit) {
   ASSERT(Marking::MarkBitFrom(obj) == mark_bit);
   if (!mark_bit.Get()) {
     mark_bit.Set();
     MemoryChunk::IncrementLiveBytesFromGC(obj->address(), obj->Size());
     ProcessNewlyMarkedObject(obj);
   }
 }
 
 
-bool MarkCompactCollector::MarkObjectWithoutPush(HeapObject* object) {
-  MarkBit mark = Marking::MarkBitFrom(object);
-  bool old_mark = mark.Get();
-  if (!old_mark) SetMark(object, mark);
-  return old_mark;
+bool MarkCompactCollector::MarkObjectWithoutPush(HeapObject* obj) {
+  MarkBit mark_bit = Marking::MarkBitFrom(obj);
+  if (!mark_bit.Get()) {
+    SetMark(obj, mark_bit);
+    return true;
+  }
+  return false;
 }
 
 
-void MarkCompactCollector::MarkObjectAndPush(HeapObject* object) {
-  if (!MarkObjectWithoutPush(object)) marking_deque_.PushBlack(object);
-}
-
-
 void MarkCompactCollector::SetMark(HeapObject* obj, MarkBit mark_bit) {
   ASSERT(!mark_bit.Get());
   ASSERT(Marking::MarkBitFrom(obj) == mark_bit);
   mark_bit.Set();
   MemoryChunk::IncrementLiveBytesFromGC(obj->address(), obj->Size());
   if (obj->IsMap()) {
     heap_->ClearCacheOnMap(Map::cast(obj));
   }
 }
 
@@ skipping 17 matching lines @@
                             SlotsBuffer::FAIL_ON_OVERFLOW)) {
       EvictEvacuationCandidate(object_page);
     }
   }
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_MARK_COMPACT_INL_H_