[heap] Simplify MarkingDeque implementation.

src/heap/mark-compact-inl.h

Index: src/heap/mark-compact-inl.h
diff --git a/src/heap/mark-compact-inl.h b/src/heap/mark-compact-inl.h
index d38e31e55602c14a874814ca5605facc46b61e43..015440bc40f222e314a11de2973cb23e981db854 100644
--- a/src/heap/mark-compact-inl.h
+++ b/src/heap/mark-compact-inl.h
@@ -23,13 +23,21 @@ void MarkCompactCollector::SetFlags(int flags) {
 }
 
 
+void MarkCompactCollector::PushBlack(HeapObject* obj) {

[Michael Lippautz, 2015/08/14 12:44:36]

Suggestion: We could return the status of the operation here, turning most
callers of this function into
  if (!PushBlack(object)) return;

[Michael Starzinger, 2015/08/14 13:23:13]

Acknowledged. Would you be fine with doing this as a follow-up?

[Michael Lippautz, 2015/08/14 13:26:46]

Sure.

+  if (marking_deque_.PushBlack(obj)) {
+    MemoryChunk::IncrementLiveBytesFromGC(obj, obj->Size());
+  } else {
+    Marking::BlackToGrey(obj);
+  }
+}
+
+
 void MarkCompactCollector::MarkObject(HeapObject* obj, MarkBit mark_bit) {
   DCHECK(Marking::MarkBitFrom(obj) == mark_bit);
   if (Marking::IsWhite(mark_bit)) {
     Marking::WhiteToBlack(mark_bit);
-    MemoryChunk::IncrementLiveBytesFromGC(obj, obj->Size());
     DCHECK(obj->GetIsolate()->heap()->Contains(obj));
-    marking_deque_.PushBlack(obj);
+    PushBlack(obj);
   }
 }