[heap] Black allocation.

src/heap/remembered-set.cc

 // Copyright 2016 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/remembered-set.h"
 #include "src/heap/heap-inl.h"
 #include "src/heap/heap.h"
 #include "src/heap/mark-compact.h"
 #include "src/heap/slot-set.h"
 #include "src/heap/spaces.h"
@@ skipping 15 matching lines @@
         Object** slot = reinterpret_cast<Object**>(addr);
         return IsValidSlot(heap, slot) ? KEEP_SLOT : REMOVE_SLOT;
       });
     }
   }
 }
 
 template <PointerDirection direction>
 void RememberedSet<direction>::VerifyValidSlots(Heap* heap) {
   Iterate(heap, [heap](Address addr) {
-    HeapObject* obj =
-        heap->mark_compact_collector()->FindBlackObjectBySlotSlow(addr);
-    if (obj == nullptr) {
-      // The slot is in dead object.
-      MemoryChunk* chunk = MemoryChunk::FromAnyPointerAddress(heap, addr);
-      AllocationSpace owner = chunk->owner()->identity();
-      // The old to old remembered set should not have dead slots.
-      CHECK_NE(direction, OLD_TO_OLD);
-      // The old to new remembered set is allowed to have slots in dead
-      // objects only in map and large object space because these spaces cannot
-      // have raw untaged pointers.
-      CHECK(owner == MAP_SPACE || owner == LO_SPACE);
-    } else {
-      int offset = static_cast<int>(addr - obj->address());
-      CHECK(obj->IsValidSlot(offset));
+    if (!Page::FromAddress(addr)->IsFlagSet(Page::BLACK_PAGE)) {
+      HeapObject* obj =
+          heap->mark_compact_collector()->FindBlackObjectBySlotSlow(addr);
+      if (obj == nullptr) {
+        // The slot is in dead object.
+        MemoryChunk* chunk = MemoryChunk::FromAnyPointerAddress(heap, addr);
+        AllocationSpace owner = chunk->owner()->identity();
+        // The old to old remembered set should not have dead slots.
+        CHECK_NE(direction, OLD_TO_OLD);
+        // The old to new remembered set is allowed to have slots in dead
+        // objects only in map and large object space because these space
+        // cannot have raw untagged pointers.
+        CHECK(owner == MAP_SPACE || owner == LO_SPACE);
+      } else {
+        int offset = static_cast<int>(addr - obj->address());
+        CHECK(obj->IsValidSlot(offset));
+      }
     }
     return KEEP_SLOT;
   });
 }
 
 template <PointerDirection direction>
 bool RememberedSet<direction>::IsValidSlot(Heap* heap, Object** slot) {
   STATIC_ASSERT(direction == OLD_TO_NEW);
   Object* object = *slot;
   if (!heap->InNewSpace(object)) {
     return false;
   }
   HeapObject* heap_object = HeapObject::cast(object);
   // If the target object is not black, the source slot must be part
   // of a non-black (dead) object.
   return Marking::IsBlack(Marking::MarkBitFrom(heap_object)) &&
          heap->mark_compact_collector()->IsSlotInLiveObject(
              reinterpret_cast<Address>(slot));
 }
 
 template void RememberedSet<OLD_TO_NEW>::ClearInvalidSlots(Heap* heap);
 template void RememberedSet<OLD_TO_NEW>::VerifyValidSlots(Heap* heap);
 template void RememberedSet<OLD_TO_OLD>::VerifyValidSlots(Heap* heap);
 
 }  // namespace internal
 }  // namespace v8