Make incremental marker post-process JSWeakCollection.

src/objects-visiting-inl.h

 // 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.
 
 #ifndef V8_OBJECTS_VISITING_INL_H_
 #define V8_OBJECTS_VISITING_INL_H_
 
 
 namespace v8 {
 namespace internal {
@@ skipping 48 matching lines @@
   table_.Register(kVisitJSFunction, &VisitJSFunction);
 
   table_.Register(kVisitJSArrayBuffer, &VisitJSArrayBuffer);
 
   table_.Register(kVisitJSTypedArray, &VisitJSTypedArray);
 
   table_.Register(kVisitJSDataView, &VisitJSDataView);
 
   table_.Register(kVisitFreeSpace, &VisitFreeSpace);
 
-  table_.Register(kVisitJSWeakMap, &JSObjectVisitor::Visit);
-
-  table_.Register(kVisitJSWeakSet, &JSObjectVisitor::Visit);
+  table_.Register(kVisitJSWeakCollection, &JSObjectVisitor::Visit);
 
   table_.Register(kVisitJSRegExp, &JSObjectVisitor::Visit);
 
   table_.template RegisterSpecializations<DataObjectVisitor,
                                           kVisitDataObject,
                                           kVisitDataObjectGeneric>();
 
   table_.template RegisterSpecializations<JSObjectVisitor,
                                           kVisitJSObject,
                                           kVisitJSObjectGeneric>();
@@ skipping 93 matching lines @@
   table_.Register(kVisitAllocationSite, &VisitAllocationSite);
 
   table_.Register(kVisitByteArray, &DataObjectVisitor::Visit);
 
   table_.Register(kVisitFreeSpace, &DataObjectVisitor::Visit);
 
   table_.Register(kVisitSeqOneByteString, &DataObjectVisitor::Visit);
 
   table_.Register(kVisitSeqTwoByteString, &DataObjectVisitor::Visit);
 
-  table_.Register(kVisitJSWeakMap, &StaticVisitor::VisitWeakCollection);
-
-  table_.Register(kVisitJSWeakSet, &StaticVisitor::VisitWeakCollection);
+  table_.Register(kVisitJSWeakCollection, &VisitWeakCollection);
 
   table_.Register(kVisitOddball,
                   &FixedBodyVisitor<StaticVisitor,
                   Oddball::BodyDescriptor,
                   void>::Visit);
 
   table_.Register(kVisitMap, &VisitMap);
 
   table_.Register(kVisitCode, &VisitCode);
 
@@ skipping 81 matching lines @@
 
 
 template<typename StaticVisitor>
 void StaticMarkingVisitor<StaticVisitor>::VisitCodeTarget(
     Heap* heap, RelocInfo* rinfo) {
   ASSERT(RelocInfo::IsCodeTarget(rinfo->rmode()));
   Code* target = Code::GetCodeFromTargetAddress(rinfo->target_address());
   // Monomorphic ICs are preserved when possible, but need to be flushed
   // when they might be keeping a Context alive, or when the heap is about
   // to be serialized.
-
   if (FLAG_cleanup_code_caches_at_gc && target->is_inline_cache_stub()
       && (target->ic_state() == MEGAMORPHIC || target->ic_state() == GENERIC ||
           target->ic_state() == POLYMORPHIC || heap->flush_monomorphic_ics() ||
           heap->isolate()->serializer_enabled() ||
           target->ic_age() != heap->global_ic_age() ||
           target->is_invalidated_weak_stub())) {
     IC::Clear(heap->isolate(), rinfo->pc(), rinfo->host()->constant_pool());
     target = Code::GetCodeFromTargetAddress(rinfo->target_address());
   }
   heap->mark_compact_collector()->RecordRelocSlot(rinfo, target);
@@ skipping 95 matching lines @@
     StaticVisitor::VisitPointer(heap, slot);
   }
 
   StaticVisitor::VisitPointers(heap,
       HeapObject::RawField(object, AllocationSite::kPointerFieldsBeginOffset),
       HeapObject::RawField(object, AllocationSite::kPointerFieldsEndOffset));
 }
 
 
 template<typename StaticVisitor>
+void StaticMarkingVisitor<StaticVisitor>::VisitWeakCollection(
+    Map* map, HeapObject* object) {
+  Heap* heap = map->GetHeap();
+  JSWeakCollection* weak_collection =
+      reinterpret_cast<JSWeakCollection*>(object);
+  MarkCompactCollector* collector = heap->mark_compact_collector();
+
+  // Enqueue weak map in linked list of encountered weak maps.
+  if (weak_collection->next() == heap->undefined_value()) {
+    weak_collection->set_next(collector->encountered_weak_collections());
+    collector->set_encountered_weak_collections(weak_collection);
+  }
+
+  // Skip visiting the backing hash table containing the mappings and the
+  // pointer to the other enqueued weak collections, both are post-processed.
+  StaticVisitor::VisitPointers(heap,
+      HeapObject::RawField(object, JSWeakCollection::kPropertiesOffset),
+      HeapObject::RawField(object, JSWeakCollection::kTableOffset));
+  STATIC_ASSERT(JSWeakCollection::kTableOffset + kPointerSize ==
+      JSWeakCollection::kNextOffset);
+  STATIC_ASSERT(JSWeakCollection::kNextOffset + kPointerSize ==
+      JSWeakCollection::kSize);
+
+  if (!weak_collection->table()->IsHashTable()) return;
+
+  // Mark the backing hash table without pushing it on the marking stack.
+  Object** slot = HeapObject::RawField(object, JSWeakCollection::kTableOffset);
+  HeapObject* obj = HeapObject::cast(*slot);
+  heap->mark_compact_collector()->RecordSlot(slot, slot, obj);
+  StaticVisitor::MarkObjectWithoutPush(heap, obj);
+}
+
+
+template<typename StaticVisitor>
 void StaticMarkingVisitor<StaticVisitor>::VisitCode(
     Map* map, HeapObject* object) {
   Heap* heap = map->GetHeap();
   Code* code = Code::cast(object);
   if (FLAG_age_code && !heap->isolate()->serializer_enabled()) {
     code->MakeOlder(heap->mark_compact_collector()->marking_parity());
   }
   code->CodeIterateBody<StaticVisitor>(heap);
 }
 
@@ skipping 515 matching lines @@
   RelocIterator it(this, mode_mask);
   for (; !it.done(); it.next()) {
     it.rinfo()->template Visit<StaticVisitor>(heap);
   }
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_OBJECTS_VISITING_INL_H_