Refactor incremental marking to use static visitor.

src/mark-compact.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 920 matching lines @@
   // page dirty marks. Therefore, we only replace the string with its left
   // substring when page dirty marks do not change.
   Object* first = reinterpret_cast<ConsString*>(object)->unchecked_first();
   if (!heap->InNewSpace(object) && heap->InNewSpace(first)) return object;
 
   *p = first;
   return HeapObject::cast(first);
 }
 
 
-class StaticMarkingVisitor : public StaticVisitorBase {
+class MarkCompactMarkingVisitor
+    : public StaticMarkingVisitor<MarkCompactMarkingVisitor> {
  public:
-  static inline void IterateBody(Map* map, HeapObject* obj) {
-    table_.GetVisitor(map)(map, obj);
-  }
-
   static void Initialize();
 
   INLINE(static void VisitPointer(Heap* heap, Object** p)) {
     MarkObjectByPointer(heap->mark_compact_collector(), p, p);
   }
 
   INLINE(static void VisitPointers(Heap* heap, Object** start, Object** end)) {
     // Mark all objects pointed to in [start, end).
     const int kMinRangeForMarkingRecursion = 64;
     if (end - start >= kMinRangeForMarkingRecursion) {
       if (VisitUnmarkedObjects(heap, start, end)) return;
       // We are close to a stack overflow, so just mark the objects.
     }
     MarkCompactCollector* collector = heap->mark_compact_collector();
     for (Object** p = start; p < end; p++) {
       MarkObjectByPointer(collector, start, p);
     }
   }
 
-  static void VisitGlobalPropertyCell(Heap* heap, RelocInfo* rinfo) {
-    ASSERT(rinfo->rmode() == RelocInfo::GLOBAL_PROPERTY_CELL);
-    JSGlobalPropertyCell* cell =
-        JSGlobalPropertyCell::cast(rinfo->target_cell());
-    MarkBit mark = Marking::MarkBitFrom(cell);
-    heap->mark_compact_collector()->MarkObject(cell, mark);
+  INLINE(static void MarkObject(Heap* heap, HeapObject* object)) {
+    MarkBit mark = Marking::MarkBitFrom(object);
+    heap->mark_compact_collector()->MarkObject(object, mark);
   }
 
   static inline void VisitEmbeddedPointer(Heap* heap, RelocInfo* rinfo) {
     ASSERT(rinfo->rmode() == RelocInfo::EMBEDDED_OBJECT);
     // TODO(mstarzinger): We do not short-circuit cons strings here, verify
     // that there can be no such embedded pointers and add assertion here.
     HeapObject* object = HeapObject::cast(rinfo->target_object());
     heap->mark_compact_collector()->RecordRelocSlot(rinfo, object);
-    MarkBit mark = Marking::MarkBitFrom(object);
-    heap->mark_compact_collector()->MarkObject(object, mark);
+    MarkObject(heap, object);
   }
 
   static inline void VisitCodeTarget(Heap* heap, RelocInfo* rinfo) {
     ASSERT(RelocInfo::IsCodeTarget(rinfo->rmode()));
     Code* target = Code::GetCodeFromTargetAddress(rinfo->target_address());
     if (FLAG_cleanup_code_caches_at_gc && target->is_inline_cache_stub()
         && (target->ic_state() == MEGAMORPHIC ||
             heap->mark_compact_collector()->flush_monomorphic_ics_ ||
             target->ic_age() != heap->global_ic_age())) {
       IC::Clear(rinfo->pc());
       target = Code::GetCodeFromTargetAddress(rinfo->target_address());
     }
-    MarkBit code_mark = Marking::MarkBitFrom(target);
-    heap->mark_compact_collector()->MarkObject(target, code_mark);
     heap->mark_compact_collector()->RecordRelocSlot(rinfo, target);
-  }
-
-  static inline void VisitDebugTarget(Heap* heap, RelocInfo* rinfo) {
-    ASSERT((RelocInfo::IsJSReturn(rinfo->rmode()) &&
-            rinfo->IsPatchedReturnSequence()) ||
-           (RelocInfo::IsDebugBreakSlot(rinfo->rmode()) &&
-            rinfo->IsPatchedDebugBreakSlotSequence()));
-    Code* target = Code::GetCodeFromTargetAddress(rinfo->call_address());
-    MarkBit code_mark = Marking::MarkBitFrom(target);
-    heap->mark_compact_collector()->MarkObject(target, code_mark);
-    heap->mark_compact_collector()->RecordRelocSlot(rinfo, target);
+    MarkObject(heap, target);
   }
 
   // Mark object pointed to by p.
   INLINE(static void MarkObjectByPointer(MarkCompactCollector* collector,
                                          Object** anchor_slot,
                                          Object** p)) {
     if (!(*p)->IsHeapObject()) return;
     HeapObject* object = ShortCircuitConsString(p);
     collector->RecordSlot(anchor_slot, p, object);
     MarkBit mark = Marking::MarkBitFrom(object);
@@ skipping 34 matching lines @@
       if (!o->IsHeapObject()) continue;
       collector->RecordSlot(start, p, o);
       HeapObject* obj = HeapObject::cast(o);
       MarkBit mark = Marking::MarkBitFrom(obj);
       if (mark.Get()) continue;
       VisitUnmarkedObject(collector, obj);
     }
     return true;
   }
 
-  static inline void VisitExternalReference(Address* p) { }
-  static inline void VisitExternalReference(RelocInfo* rinfo) { }
-  static inline void VisitRuntimeEntry(RelocInfo* rinfo) { }
-
- private:
-  class DataObjectVisitor {
-   public:
-    template<int size>
-    static void VisitSpecialized(Map* map, HeapObject* object) {
+  static void VisitCode(Map* map, HeapObject* object) {
+    Heap* heap = map->GetHeap();
+    Code* code = reinterpret_cast<Code*>(object);
+    if (FLAG_cleanup_code_caches_at_gc) {
+      code->ClearTypeFeedbackCells(heap);
     }
-
-    static void Visit(Map* map, HeapObject* object) {
-    }
-  };
-
-  typedef FlexibleBodyVisitor<StaticMarkingVisitor,
-                              JSObject::BodyDescriptor,
-                              void> JSObjectVisitor;
-
-  typedef FlexibleBodyVisitor<StaticMarkingVisitor,
-                              StructBodyDescriptor,
-                              void> StructObjectVisitor;
-
-  template<int id>
-  static inline void TrackObjectStatsAndVisit(Map* map, HeapObject* obj);
+    code->CodeIterateBody<MarkCompactMarkingVisitor>(heap);
+  }
 
   static void VisitJSWeakMap(Map* map, HeapObject* object) {
     MarkCompactCollector* collector = map->GetHeap()->mark_compact_collector();
     JSWeakMap* weak_map = reinterpret_cast<JSWeakMap*>(object);
 
     // Enqueue weak map in linked list of encountered weak maps.
     if (weak_map->next() == Smi::FromInt(0)) {
       weak_map->set_next(collector->encountered_weak_maps());
       collector->set_encountered_weak_maps(weak_map);
     }
 
     // Skip visiting the backing hash table containing the mappings.
     int object_size = JSWeakMap::BodyDescriptor::SizeOf(map, object);
-    BodyVisitorBase<StaticMarkingVisitor>::IteratePointers(
+    BodyVisitorBase<MarkCompactMarkingVisitor>::IteratePointers(
         map->GetHeap(),
         object,
         JSWeakMap::BodyDescriptor::kStartOffset,
         JSWeakMap::kTableOffset);
-    BodyVisitorBase<StaticMarkingVisitor>::IteratePointers(
+    BodyVisitorBase<MarkCompactMarkingVisitor>::IteratePointers(
         map->GetHeap(),
         object,
         JSWeakMap::kTableOffset + kPointerSize,
         object_size);
 
     // Mark the backing hash table without pushing it on the marking stack.
     Object* table_object = weak_map->table();
     if (!table_object->IsHashTable()) return;
     ObjectHashTable* table = ObjectHashTable::cast(table_object);
     Object** table_slot =
         HeapObject::RawField(weak_map, JSWeakMap::kTableOffset);
     MarkBit table_mark = Marking::MarkBitFrom(table);
     collector->RecordSlot(table_slot, table_slot, table);
     if (!table_mark.Get()) collector->SetMark(table, table_mark);
     // Recording the map slot can be skipped, because maps are not compacted.
     collector->MarkObject(table->map(), Marking::MarkBitFrom(table->map()));
     ASSERT(MarkCompactCollector::IsMarked(table->map()));
   }
 
-  static void VisitCode(Map* map, HeapObject* object) {
-    Heap* heap = map->GetHeap();
-    Code* code = reinterpret_cast<Code*>(object);
-    if (FLAG_cleanup_code_caches_at_gc) {
-      code->ClearTypeFeedbackCells(heap);
-    }
-    code->CodeIterateBody<StaticMarkingVisitor>(heap);
-  }
+ private:
+  template<int id>
+  static inline void TrackObjectStatsAndVisit(Map* map, HeapObject* obj);
 
   // Code flushing support.
 
   // How many collections newly compiled code object will survive before being
   // flushed.
   static const int kCodeAgeThreshold = 5;
 
   static const int kRegExpCodeThreshold = 5;
 
   inline static bool HasSourceCode(Heap* heap, SharedFunctionInfo* info) {
@@ skipping 94 matching lines @@
 
   static inline bool IsValidNotBuiltinContext(Object* ctx) {
     return ctx->IsContext() &&
         !Context::cast(ctx)->global()->IsJSBuiltinsObject();
   }
 
 
   static void VisitSharedFunctionInfoGeneric(Map* map, HeapObject* object) {
     SharedFunctionInfo::cast(object)->BeforeVisitingPointers();
 
-    FixedBodyVisitor<StaticMarkingVisitor,
+    FixedBodyVisitor<MarkCompactMarkingVisitor,
                      SharedFunctionInfo::BodyDescriptor,
                      void>::Visit(map, object);
   }
 
 
   static void UpdateRegExpCodeAgeAndFlush(Heap* heap,
                                           JSRegExp* re,
                                           bool is_ascii) {
     // Make sure that the fixed array is in fact initialized on the RegExp.
     // We could potentially trigger a GC when initializing the RegExp.
@@ skipping 47 matching lines @@
 
   // Works by setting the current sweep_generation (as a smi) in the
   // code object place in the data array of the RegExp and keeps a copy
   // around that can be reinstated if we reuse the RegExp before flushing.
   // If we did not use the code for kRegExpCodeThreshold mark sweep GCs
   // we flush the code.
   static void VisitRegExpAndFlushCode(Map* map, HeapObject* object) {
     Heap* heap = map->GetHeap();
     MarkCompactCollector* collector = heap->mark_compact_collector();
     if (!collector->is_code_flushing_enabled()) {
-      VisitJSRegExpFields(map, object);
+      VisitJSRegExp(map, object);
       return;
     }
     JSRegExp* re = reinterpret_cast<JSRegExp*>(object);
     // Flush code or set age on both ASCII and two byte code.
     UpdateRegExpCodeAgeAndFlush(heap, re, true);
     UpdateRegExpCodeAgeAndFlush(heap, re, false);
     // Visit the fields of the RegExp, including the updated FixedArray.
-    VisitJSRegExpFields(map, object);
+    VisitJSRegExp(map, object);
   }
 
 
   static void VisitSharedFunctionInfoAndFlushCode(Map* map,
                                                   HeapObject* object) {
     Heap* heap = map->GetHeap();
     SharedFunctionInfo* shared = reinterpret_cast<SharedFunctionInfo*>(object);
     if (shared->ic_age() != heap->global_ic_age()) {
       shared->ResetForNewContext(heap->global_ic_age());
     }
@@ skipping 18 matching lines @@
       known_flush_code_candidate = IsFlushable(heap, shared);
       if (known_flush_code_candidate) {
         heap->mark_compact_collector()->code_flusher()->AddCandidate(shared);
       }
     }
 
     VisitSharedFunctionInfoFields(heap, object, known_flush_code_candidate);
   }
 
 
-  static void VisitCodeEntry(Heap* heap, Address entry_address) {
-    Code* code = Code::cast(Code::GetObjectFromEntryAddress(entry_address));
-    MarkBit mark = Marking::MarkBitFrom(code);
-    heap->mark_compact_collector()->MarkObject(code, mark);
-    heap->mark_compact_collector()->
-        RecordCodeEntrySlot(entry_address, code);
-  }
-
-  static void VisitGlobalContext(Map* map, HeapObject* object) {
-    FixedBodyVisitor<StaticMarkingVisitor,
-                     Context::MarkCompactBodyDescriptor,
-                     void>::Visit(map, object);
-
-    MarkCompactCollector* collector = map->GetHeap()->mark_compact_collector();
-    for (int idx = Context::FIRST_WEAK_SLOT;
-         idx < Context::GLOBAL_CONTEXT_SLOTS;
-         ++idx) {
-      Object** slot =
-          HeapObject::RawField(object, FixedArray::OffsetOfElementAt(idx));
-      collector->RecordSlot(slot, slot, *slot);
-    }
-  }
-
   static void VisitJSFunctionAndFlushCode(Map* map, HeapObject* object) {
     Heap* heap = map->GetHeap();
     MarkCompactCollector* collector = heap->mark_compact_collector();
     if (!collector->is_code_flushing_enabled()) {
       VisitJSFunction(map, object);
       return;
     }
 
     JSFunction* jsfunction = reinterpret_cast<JSFunction*>(object);
     // The function must have a valid context and not be a builtin.
@@ skipping 61 matching lines @@
     }
 
     VisitPointers(
         heap,
         HeapObject::RawField(object,
                              JSFunction::kCodeEntryOffset + kPointerSize),
         HeapObject::RawField(object,
                              JSFunction::kNonWeakFieldsEndOffset));
   }
 
-  static inline void VisitJSRegExpFields(Map* map,
-                                         HeapObject* object) {
-    int last_property_offset =
-        JSRegExp::kSize + kPointerSize * map->inobject_properties();
-    VisitPointers(map->GetHeap(),
-                  SLOT_ADDR(object, JSRegExp::kPropertiesOffset),
-                  SLOT_ADDR(object, last_property_offset));
-  }
-
 
   static void VisitSharedFunctionInfoFields(Heap* heap,
                                             HeapObject* object,
                                             bool flush_code_candidate) {
     VisitPointer(heap, SLOT_ADDR(object, SharedFunctionInfo::kNameOffset));
 
     if (!flush_code_candidate) {
       VisitPointer(heap, SLOT_ADDR(object, SharedFunctionInfo::kCodeOffset));
     }
 
     VisitPointers(heap,
         SLOT_ADDR(object, SharedFunctionInfo::kOptimizedCodeMapOffset),
         SLOT_ADDR(object, SharedFunctionInfo::kSize));
   }
 
   #undef SLOT_ADDR
 
-  typedef void (*Callback)(Map* map, HeapObject* object);
-
-  static VisitorDispatchTable<Callback> table_;
   static VisitorDispatchTable<Callback> non_count_table_;
 };
 
 
 template<int id>
-void StaticMarkingVisitor::TrackObjectStatsAndVisit(Map* map, HeapObject* obj) {
+void MarkCompactMarkingVisitor::TrackObjectStatsAndVisit(Map* map,
+                                                         HeapObject* obj) {
   Heap* heap = map->GetHeap();
   int object_size = obj->Size();
   heap->RecordObjectStats(map->instance_type(), -1, object_size);
   non_count_table_.GetVisitorById(static_cast<VisitorId>(id))(map, obj);
 }
 
 
 template<>
-void StaticMarkingVisitor::TrackObjectStatsAndVisit<
-    StaticMarkingVisitor::kVisitCode>(Map* map, HeapObject* obj) {
+void MarkCompactMarkingVisitor::TrackObjectStatsAndVisit<
+    MarkCompactMarkingVisitor::kVisitCode>(Map* map, HeapObject* obj) {
   Heap* heap = map->GetHeap();
   int object_size = obj->Size();
   ASSERT(map->instance_type() == CODE_TYPE);
   heap->RecordObjectStats(CODE_TYPE, -1, object_size);
   heap->RecordObjectStats(CODE_TYPE, Code::cast(obj)->kind(), object_size);
   non_count_table_.GetVisitorById(static_cast<VisitorId>(kVisitCode))(map, obj);
 }
 
 
-void StaticMarkingVisitor::Initialize() {
-  table_.Register(kVisitShortcutCandidate,
-                  &FixedBodyVisitor<StaticMarkingVisitor,
-                  ConsString::BodyDescriptor,
-                  void>::Visit);
-
-  table_.Register(kVisitConsString,
-                  &FixedBodyVisitor<StaticMarkingVisitor,
-                  ConsString::BodyDescriptor,
-                  void>::Visit);
-
-  table_.Register(kVisitSlicedString,
-                  &FixedBodyVisitor<StaticMarkingVisitor,
-                  SlicedString::BodyDescriptor,
-                  void>::Visit);
-
-  table_.Register(kVisitFixedArray,
-                  &FlexibleBodyVisitor<StaticMarkingVisitor,
-                  FixedArray::BodyDescriptor,
-                  void>::Visit);
-
-  table_.Register(kVisitGlobalContext, &VisitGlobalContext);
-
-  table_.Register(kVisitFixedDoubleArray, DataObjectVisitor::Visit);
-
-  table_.Register(kVisitByteArray, &DataObjectVisitor::Visit);
-  table_.Register(kVisitFreeSpace, &DataObjectVisitor::Visit);
-  table_.Register(kVisitSeqAsciiString, &DataObjectVisitor::Visit);
-  table_.Register(kVisitSeqTwoByteString, &DataObjectVisitor::Visit);
-
-  table_.Register(kVisitJSWeakMap, &VisitJSWeakMap);
-
-  table_.Register(kVisitOddball,
-                  &FixedBodyVisitor<StaticMarkingVisitor,
-                  Oddball::BodyDescriptor,
-                  void>::Visit);
-  table_.Register(kVisitMap,
-                  &FixedBodyVisitor<StaticMarkingVisitor,
-                  Map::BodyDescriptor,
-                  void>::Visit);
-
-  table_.Register(kVisitCode, &VisitCode);
+void MarkCompactMarkingVisitor::Initialize() {
+  StaticMarkingVisitor<MarkCompactMarkingVisitor>::Initialize();
 
   table_.Register(kVisitSharedFunctionInfo,
                   &VisitSharedFunctionInfoAndFlushCode);
 
   table_.Register(kVisitJSFunction,
                   &VisitJSFunctionAndFlushCode);
 
   table_.Register(kVisitJSRegExp,
                   &VisitRegExpAndFlushCode);
 
-  table_.Register(kVisitPropertyCell,
-                  &FixedBodyVisitor<StaticMarkingVisitor,
-                  JSGlobalPropertyCell::BodyDescriptor,
-                  void>::Visit);
-
-  table_.RegisterSpecializations<DataObjectVisitor,
-      kVisitDataObject,
-      kVisitDataObjectGeneric>();
-
-  table_.RegisterSpecializations<JSObjectVisitor,
-      kVisitJSObject,
-      kVisitJSObjectGeneric>();
-
-  table_.RegisterSpecializations<StructObjectVisitor,
-      kVisitStruct,
-      kVisitStructGeneric>();
-
   if (FLAG_track_gc_object_stats) {
     // Copy the visitor table to make call-through possible.
     non_count_table_.CopyFrom(&table_);
 #define VISITOR_ID_COUNT_FUNCTION(id)                                   \
     table_.Register(kVisit##id, TrackObjectStatsAndVisit<kVisit##id>);
     VISITOR_ID_LIST(VISITOR_ID_COUNT_FUNCTION)
 #undef VISITOR_ID_COUNT_FUNCTION
   }
 }
 
 
-VisitorDispatchTable<StaticMarkingVisitor::Callback>
-  StaticMarkingVisitor::table_;
-VisitorDispatchTable<StaticMarkingVisitor::Callback>
-  StaticMarkingVisitor::non_count_table_;
+VisitorDispatchTable<MarkCompactMarkingVisitor::Callback>
+    MarkCompactMarkingVisitor::non_count_table_;
 
 
 class MarkingVisitor : public ObjectVisitor {
  public:
   explicit MarkingVisitor(Heap* heap) : heap_(heap) { }
 
   void VisitPointer(Object** p) {
-    StaticMarkingVisitor::VisitPointer(heap_, p);
+    MarkCompactMarkingVisitor::VisitPointer(heap_, p);
   }
 
   void VisitPointers(Object** start, Object** end) {
-    StaticMarkingVisitor::VisitPointers(heap_, start, end);
+    MarkCompactMarkingVisitor::VisitPointers(heap_, start, end);
   }
 
  private:
   Heap* heap_;
 };
 
 
 class CodeMarkingVisitor : public ThreadVisitor {
  public:
   explicit CodeMarkingVisitor(MarkCompactCollector* collector)
@@ skipping 138 matching lines @@
     MarkBit mark_bit = Marking::MarkBitFrom(object);
     if (mark_bit.Get()) return;
 
     Map* map = object->map();
     // Mark the object.
     collector_->SetMark(object, mark_bit);
 
     // Mark the map pointer and body, and push them on the marking stack.
     MarkBit map_mark = Marking::MarkBitFrom(map);
     collector_->MarkObject(map, map_mark);
-    StaticMarkingVisitor::IterateBody(map, object);
+    MarkCompactMarkingVisitor::IterateBody(map, object);
 
     // Mark all the objects reachable from the map and body.  May leave
     // overflowed objects in the heap.
     collector_->EmptyMarkingDeque();
   }
 
   MarkCompactCollector* collector_;
 };
 
 
@@ skipping 449 matching lines @@
     while (!marking_deque_.IsEmpty()) {
       HeapObject* object = marking_deque_.Pop();
       ASSERT(object->IsHeapObject());
       ASSERT(heap()->Contains(object));
       ASSERT(Marking::IsBlack(Marking::MarkBitFrom(object)));
 
       Map* map = object->map();
       MarkBit map_mark = Marking::MarkBitFrom(map);
       MarkObject(map, map_mark);
 
-      StaticMarkingVisitor::IterateBody(map, object);
+      MarkCompactMarkingVisitor::IterateBody(map, object);
     }
 
     // Process encountered weak maps, mark objects only reachable by those
     // weak maps and repeat until fix-point is reached.
     ProcessWeakMaps();
   }
 }
 
 
 // Sweep the heap for overflowed objects, clear their overflow bits, and
@@ skipping 118 matching lines @@
   if (was_marked_incrementally_) {
     // There is no write barrier on cells so we have to scan them now at the end
     // of the incremental marking.
     {
       HeapObjectIterator cell_iterator(heap()->cell_space());
       HeapObject* cell;
       while ((cell = cell_iterator.Next()) != NULL) {
         ASSERT(cell->IsJSGlobalPropertyCell());
         if (IsMarked(cell)) {
           int offset = JSGlobalPropertyCell::kValueOffset;
-          StaticMarkingVisitor::VisitPointer(
+          MarkCompactMarkingVisitor::VisitPointer(
               heap(),
               reinterpret_cast<Object**>(cell->address() + offset));
         }
       }
     }
   }
 
   RootMarkingVisitor root_visitor(heap());
   MarkRoots(&root_visitor);
 
@@ skipping 238 matching lines @@
     Object** anchor = reinterpret_cast<Object**>(table->address());
     for (int i = 0; i < table->Capacity(); i++) {
       if (MarkCompactCollector::IsMarked(HeapObject::cast(table->KeyAt(i)))) {
         Object** key_slot =
             HeapObject::RawField(table, FixedArray::OffsetOfElementAt(
                 ObjectHashTable::EntryToIndex(i)));
         RecordSlot(anchor, key_slot, *key_slot);
         Object** value_slot =
             HeapObject::RawField(table, FixedArray::OffsetOfElementAt(
                 ObjectHashTable::EntryToValueIndex(i)));
-        StaticMarkingVisitor::MarkObjectByPointer(this, anchor, value_slot);
+        MarkCompactMarkingVisitor::MarkObjectByPointer(this, anchor, value_slot);
       }
     }
     weak_map_obj = weak_map->next();
   }
 }
 
 
 void MarkCompactCollector::ClearWeakMaps() {
   Object* weak_map_obj = encountered_weak_maps();
   while (weak_map_obj != Smi::FromInt(0)) {
@@ skipping 1378 matching lines @@
     GDBJITInterface::RemoveCode(reinterpret_cast<Code*>(obj));
   }
 #endif
   if (obj->IsCode()) {
     PROFILE(isolate, CodeDeleteEvent(obj->address()));
   }
 }
 
 
 void MarkCompactCollector::Initialize() {
-  StaticMarkingVisitor::Initialize();
+  MarkCompactMarkingVisitor::Initialize();
+  IncrementalMarking::Initialize();
 }
 
 
 bool SlotsBuffer::IsTypedSlot(ObjectSlot slot) {
   return reinterpret_cast<uintptr_t>(slot) < NUMBER_OF_SLOT_TYPES;
 }
 
 
 bool SlotsBuffer::AddTo(SlotsBufferAllocator* allocator,
                         SlotsBuffer** buffer_address,
@@ skipping 124 matching lines @@
   while (buffer != NULL) {
     SlotsBuffer* next_buffer = buffer->next();
     DeallocateBuffer(buffer);
     buffer = next_buffer;
   }
   *buffer_address = NULL;
 }
 
 
 } }  // namespace v8::internal