[heap] Provide ObjectMarking with marking transitions

src/heap/mark-compact.cc

 // 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.
 
 #include "src/heap/mark-compact.h"
 
 #include "src/base/atomicops.h"
 #include "src/base/bits.h"
 #include "src/base/sys-info.h"
 #include "src/code-stubs.h"
@@ skipping 380 matching lines @@
 
 
 void MarkCompactCollector::ClearMarkbits() {
   ClearMarkbitsInPagedSpace(heap_->code_space());
   ClearMarkbitsInPagedSpace(heap_->map_space());
   ClearMarkbitsInPagedSpace(heap_->old_space());
   ClearMarkbitsInNewSpace(heap_->new_space());
 
   LargeObjectIterator it(heap_->lo_space());
   for (HeapObject* obj = it.Next(); obj != NULL; obj = it.Next()) {
-    Marking::MarkWhite(ObjectMarking::MarkBitFrom(obj));
+    ObjectMarking::MarkWhite(obj);
     MemoryChunk* chunk = MemoryChunk::FromAddress(obj->address());
     chunk->ResetProgressBar();
     chunk->ResetLiveBytes();
   }
 }
 
 class MarkCompactCollector::Sweeper::SweeperTask : public v8::Task {
  public:
   SweeperTask(Sweeper* sweeper, base::Semaphore* pending_sweeper_tasks,
               AllocationSpace space_to_start)
@@ skipping 1086 matching lines @@
 // is reached, whichever comes first.
 template <class T>
 void MarkCompactCollector::DiscoverGreyObjectsWithIterator(T* it) {
   // The caller should ensure that the marking stack is initially not full,
   // so that we don't waste effort pointlessly scanning for objects.
   DCHECK(!marking_deque()->IsFull());
 
   Map* filler_map = heap()->one_pointer_filler_map();
   for (HeapObject* object = it->Next(); object != NULL; object = it->Next()) {
     MarkBit markbit = ObjectMarking::MarkBitFrom(object);
     if ((object->map() != filler_map) && Marking::IsGrey(markbit)) {

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

It is a bit weird now that we still use MarkBit for getters. In this case, why
not have ObjectMarking::IsGrey(object)?

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

Done.

-      Marking::GreyToBlack(markbit);
+      ObjectMarking::GreyToBlack(object);
       PushBlack(object);
       if (marking_deque()->IsFull()) return;
     }
   }
 }
 
 void MarkCompactCollector::DiscoverGreyObjectsOnPage(MemoryChunk* p) {
   DCHECK(!marking_deque()->IsFull());
   LiveObjectIterator<kGreyObjects> it(p);
   HeapObject* object = NULL;
   while ((object = it.Next()) != NULL) {
     MarkBit markbit = ObjectMarking::MarkBitFrom(object);

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

Same here.

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

Done.

     DCHECK(Marking::IsGrey(markbit));
-    Marking::GreyToBlack(markbit);
+    ObjectMarking::GreyToBlack(object);
     PushBlack(object);
     if (marking_deque()->IsFull()) return;
   }
 }
 
 class RecordMigratedSlotVisitor final : public ObjectVisitor {
  public:
   explicit RecordMigratedSlotVisitor(MarkCompactCollector* collector)
       : collector_(collector) {}
 
@@ skipping 2550 matching lines @@
       // The target is always in old space, we don't have to record the slot in
       // the old-to-new remembered set.
       DCHECK(!heap()->InNewSpace(target));
       RecordRelocSlot(host, &rinfo, target);
     }
   }
 }
 
 }  // namespace internal
 }  // namespace v8