Reland "[heap] Fine-grained JSArrayBuffer tracking"

src/heap/scavenger.cc

 // Copyright 2015 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/scavenger.h"
 
 #include "src/contexts.h"
 #include "src/heap/heap.h"
 #include "src/heap/objects-visiting-inl.h"
 #include "src/heap/scavenger-inl.h"
@@ skipping 18 matching lines @@
  public:
   static void Initialize() {
     table_.Register(kVisitSeqOneByteString, &EvacuateSeqOneByteString);
     table_.Register(kVisitSeqTwoByteString, &EvacuateSeqTwoByteString);
     table_.Register(kVisitShortcutCandidate, &EvacuateShortcutCandidate);
     table_.Register(kVisitByteArray, &EvacuateByteArray);
     table_.Register(kVisitFixedArray, &EvacuateFixedArray);
     table_.Register(kVisitFixedDoubleArray, &EvacuateFixedDoubleArray);
     table_.Register(kVisitFixedTypedArray, &EvacuateFixedTypedArray);
     table_.Register(kVisitFixedFloat64Array, &EvacuateFixedFloat64Array);
-    table_.Register(kVisitJSArrayBuffer, &EvacuateJSArrayBuffer);
+    table_.Register(kVisitJSArrayBuffer,
+                    &ObjectEvacuationStrategy<POINTER_OBJECT>::Visit);
 
     table_.Register(
         kVisitNativeContext,
         &ObjectEvacuationStrategy<POINTER_OBJECT>::template VisitSpecialized<
             Context::kSize>);
 
     table_.Register(
         kVisitConsString,
         &ObjectEvacuationStrategy<POINTER_OBJECT>::template VisitSpecialized<
             ConsString::kSize>);
@@ skipping 224 matching lines @@
                                                  object_size);
   }
 
   static inline void EvacuateFixedFloat64Array(Map* map, HeapObject** slot,
                                                HeapObject* object) {
     int object_size = reinterpret_cast<FixedFloat64Array*>(object)->size();
     EvacuateObject<POINTER_OBJECT, kDoubleAligned>(map, slot, object,
                                                    object_size);
   }
 
-  static inline void EvacuateJSArrayBuffer(Map* map, HeapObject** slot,
-                                           HeapObject* object) {
-    ObjectEvacuationStrategy<POINTER_OBJECT>::Visit(map, slot, object);
-
-    Heap* heap = map->GetHeap();
-    MapWord map_word = object->map_word();
-    DCHECK(map_word.IsForwardingAddress());
-    HeapObject* target = map_word.ToForwardingAddress();
-    if (!heap->InNewSpace(target)) {
-      heap->array_buffer_tracker()->Promote(JSArrayBuffer::cast(target));
-    }
-  }
-
   static inline void EvacuateByteArray(Map* map, HeapObject** slot,
                                        HeapObject* object) {
     int object_size = reinterpret_cast<ByteArray*>(object)->ByteArraySize();
     EvacuateObject<DATA_OBJECT, kWordAligned>(map, slot, object, object_size);
   }
 
   static inline void EvacuateSeqOneByteString(Map* map, HeapObject** slot,
                                               HeapObject* object) {
     int object_size = SeqOneByteString::cast(object)
                           ->SeqOneByteStringSize(map->instance_type());
@@ skipping 149 matching lines @@
 
 void ScavengeVisitor::ScavengePointer(Object** p) {
   Object* object = *p;
   if (!heap_->InNewSpace(object)) return;
   Scavenger::ScavengeObject(reinterpret_cast<HeapObject**>(p),
                             reinterpret_cast<HeapObject*>(object));
 }
 
 }  // namespace internal
 }  // namespace v8