[heap] Remove markbits getter from raw address

src/heap/heap.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/heap.h"
 
 #include "src/accessors.h"
 #include "src/api.h"
 #include "src/ast/context-slot-cache.h"
 #include "src/base/bits.h"
@@ skipping 3092 matching lines @@
   instance->set_osr_loop_nesting_level(0);
   instance->set_bytecode_age(BytecodeArray::kNoAgeBytecodeAge);
   instance->set_constant_pool(constant_pool);
   instance->set_handler_table(empty_fixed_array());
   instance->set_source_position_table(empty_byte_array());
   CopyBytes(instance->GetFirstBytecodeAddress(), raw_bytecodes, length);
 
   return result;
 }
 
-void Heap::CreateFillerObjectAt(Address addr, int size,
-                                ClearRecordedSlots mode) {
-  if (size == 0) return;
+HeapObject* Heap::CreateFillerObjectAt(Address addr, int size,
+                                       ClearRecordedSlots mode) {
+  if (size == 0) return nullptr;
   HeapObject* filler = HeapObject::FromAddress(addr);
   if (size == kPointerSize) {
     filler->set_map_no_write_barrier(
         reinterpret_cast<Map*>(root(kOnePointerFillerMapRootIndex)));
   } else if (size == 2 * kPointerSize) {
     filler->set_map_no_write_barrier(
         reinterpret_cast<Map*>(root(kTwoPointerFillerMapRootIndex)));
   } else {
     DCHECK_GT(size, 2 * kPointerSize);
     filler->set_map_no_write_barrier(
         reinterpret_cast<Map*>(root(kFreeSpaceMapRootIndex)));
     FreeSpace::cast(filler)->nobarrier_set_size(size);
   }
   if (mode == ClearRecordedSlots::kYes) {
     ClearRecordedSlotRange(addr, addr + size);
   }
 
   // At this point, we may be deserializing the heap from a snapshot, and
   // none of the maps have been created yet and are NULL.
   DCHECK((filler->map() == NULL && !deserialization_complete_) ||
          filler->map()->IsMap());
+  return filler;
 }
 
 
 bool Heap::CanMoveObjectStart(HeapObject* object) {
   if (!FLAG_move_object_start) return false;
 
   // Sampling heap profiler may have a reference to the object.
   if (isolate()->heap_profiler()->is_sampling_allocations()) return false;
 
   Address address = object->address();
 
   if (lo_space()->Contains(object)) return false;
 
   // We can move the object start if the page was already swept.
   return Page::FromAddress(address)->SweepingDone();
 }
 
 void Heap::AdjustLiveBytes(HeapObject* object, int by) {
   // As long as the inspected object is black and we are currently not iterating
   // the heap using HeapIterator, we can update the live byte count. We cannot
   // update while using HeapIterator because the iterator is temporarily
   // marking the whole object graph, without updating live bytes.
   if (lo_space()->Contains(object)) {
     lo_space()->AdjustLiveBytes(by);
   } else if (!in_heap_iterator() &&
              !mark_compact_collector()->sweeping_in_progress() &&
-             Marking::IsBlack(ObjectMarking::MarkBitFrom(object->address()))) {
+             Marking::IsBlack(ObjectMarking::MarkBitFrom(object))) {
     DCHECK(MemoryChunk::FromAddress(object->address())->SweepingDone());
     MemoryChunk::IncrementLiveBytes(object, by);
   }
 }
 
 
 FixedArrayBase* Heap::LeftTrimFixedArray(FixedArrayBase* object,
                                          int elements_to_trim) {
   CHECK_NOT_NULL(object);
   DCHECK(!object->IsFixedTypedArrayBase());
@@ skipping 15 matching lines @@
   const int len = object->length();
   DCHECK(elements_to_trim <= len);
 
   // Calculate location of new array start.
   Address old_start = object->address();
   Address new_start = old_start + bytes_to_trim;
 
   // Transfer the mark bits to their new location if the object is not within
   // a black area.
   if (!incremental_marking()->black_allocation() ||
-      !Marking::IsBlack(ObjectMarking::MarkBitFrom(new_start))) {
-    IncrementalMarking::TransferMark(this, old_start, new_start);
+      !Marking::IsBlack(
+          ObjectMarking::MarkBitFrom(HeapObject::FromAddress(new_start)))) {
+    IncrementalMarking::TransferMark(this, object,
+                                     HeapObject::FromAddress(new_start));
   }
 
   // Technically in new space this write might be omitted (except for
   // debug mode which iterates through the heap), but to play safer
   // we still do it.
   CreateFillerObjectAt(old_start, bytes_to_trim, ClearRecordedSlots::kYes);
 
   // Clear the mark bits of the black area that belongs now to the filler.
   // This is an optimization. The sweeper will release black fillers anyway.
   if (incremental_marking()->black_allocation() &&
-      Marking::IsBlackOrGrey(ObjectMarking::MarkBitFrom(old_start))) {
+      Marking::IsBlackOrGrey(ObjectMarking::MarkBitFrom(object))) {
     Page* page = Page::FromAddress(old_start);
     page->markbits()->ClearRange(
         page->AddressToMarkbitIndex(old_start),
         page->AddressToMarkbitIndex(old_start + bytes_to_trim));
   }
 
   // Initialize header of the trimmed array. Since left trimming is only
   // performed on pages which are not concurrently swept creating a filler
   // object does not require synchronization.
   DCHECK(CanMoveObjectStart(object));
@@ skipping 54 matching lines @@
   Address old_end = object->address() + object->Size();
   Address new_end = old_end - bytes_to_trim;
 
   // Technically in new space this write might be omitted (except for
   // debug mode which iterates through the heap), but to play safer
   // we still do it.
   // We do not create a filler for objects in large object space.
   // TODO(hpayer): We should shrink the large object page if the size
   // of the object changed significantly.
   if (!lo_space()->Contains(object)) {
-    CreateFillerObjectAt(new_end, bytes_to_trim, ClearRecordedSlots::kYes);
+    HeapObject* filler =
+        CreateFillerObjectAt(new_end, bytes_to_trim, ClearRecordedSlots::kYes);
+    DCHECK_NOT_NULL(filler);
     // Clear the mark bits of the black area that belongs now to the filler.
     // This is an optimization. The sweeper will release black fillers anyway.
     if (incremental_marking()->black_allocation() &&
-        Marking::IsBlackOrGrey(ObjectMarking::MarkBitFrom(new_end))) {
+        Marking::IsBlackOrGrey(ObjectMarking::MarkBitFrom(filler))) {
       Page* page = Page::FromAddress(new_end);
       page->markbits()->ClearRange(
           page->AddressToMarkbitIndex(new_end),
           page->AddressToMarkbitIndex(new_end + bytes_to_trim));
     }
   }
 
   // Initialize header of the trimmed array. We are storing the new length
   // using release store after creating a filler for the left-over space to
   // avoid races with the sweeper thread.
@@ skipping 3261 matching lines @@
 }
 
 
 // static
 int Heap::GetStaticVisitorIdForMap(Map* map) {
   return StaticVisitorBase::GetVisitorId(map);
 }
 
 }  // namespace internal
 }  // namespace v8