Access old space marking bits from runtime only when incremental marking is in MARKING state.

src/heap.cc

 // 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
@@ skipping 3951 matching lines @@
     filler->set_map_no_write_barrier(one_pointer_filler_map());
   } else if (size == 2 * kPointerSize) {
     filler->set_map_no_write_barrier(two_pointer_filler_map());
   } else {
     filler->set_map_no_write_barrier(free_space_map());
     FreeSpace::cast(filler)->set_size(size);
   }
 }
 
 
+void Heap::AdjustLiveBytes(Address address, int by, InvocationMode mode) {
+  if (incremental_marking()->IsMarking() &&
+      Marking::IsBlack(Marking::MarkBitFrom(address))) {
+    if (mode == FROM_GC) {
+      MemoryChunk::IncrementLiveBytesFromGC(address, by);
+    } else {
+      MemoryChunk::IncrementLiveBytesFromMutator(address, by);
+    }
+  }
+}
+
+
 MaybeObject* Heap::AllocateExternalArray(int length,
                                          ExternalArrayType array_type,
                                          void* external_pointer,
                                          PretenureFlag pretenure) {
   int size = ExternalArray::kAlignedSize;
   AllocationSpace space = SelectSpace(size, OLD_DATA_SPACE, pretenure);
   Object* result;
   { MaybeObject* maybe_result = AllocateRaw(size, space, OLD_DATA_SPACE);
     if (!maybe_result->ToObject(&result)) return maybe_result;
   }
@@ skipping 3768 matching lines @@
       static_cast<int>(object_sizes_last_time_[index]));
   CODE_AGE_LIST_COMPLETE(ADJUST_LAST_TIME_OBJECT_COUNT)
 #undef ADJUST_LAST_TIME_OBJECT_COUNT
 
   OS::MemCopy(object_counts_last_time_, object_counts_, sizeof(object_counts_));
   OS::MemCopy(object_sizes_last_time_, object_sizes_, sizeof(object_sizes_));
   ClearObjectStats();
 }
 
 } }  // namespace v8::internal