Visit encountered JSWeakCollection list during scavenging.

R=hpayer@chromium.org
BUG=chromium:380068
LOG=N

Review URL: https://codereview.chromium.org/310783003

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@21655 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/heap.cc

@@ -146,6 +146,7 @@ Heap::Heap()
   set_native_contexts_list(NULL);
   set_array_buffers_list(Smi::FromInt(0));
   set_allocation_sites_list(Smi::FromInt(0));
+  set_encountered_weak_collections(Smi::FromInt(0));
   // Put a dummy entry in the remembered pages so we can find the list the
   // minidump even if there are no real unmapped pages.
   RememberUnmappedPage(NULL, false);
@@ -1529,6 +1530,9 @@ void Heap::Scavenge() {
     }
   }
 
+  // Copy objects reachable from the encountered weak collections list.
+  scavenge_visitor.VisitPointer(&encountered_weak_collections_);
+
   // Copy objects reachable from the code flushing candidates list.
   MarkCompactCollector* collector = mark_compact_collector();
   if (collector->is_code_flushing_enabled()) {

src/heap.h

@@ -849,6 +849,13 @@ class Heap {
 
   Object* weak_object_to_code_table() { return weak_object_to_code_table_; }
 
+  void set_encountered_weak_collections(Object* weak_collection) {
+    encountered_weak_collections_ = weak_collection;
+  }
+  Object* encountered_weak_collections() const {
+    return encountered_weak_collections_;
+  }
+
   // Number of mark-sweeps.
   unsigned int ms_count() { return ms_count_; }
 
@@ -1613,6 +1620,11 @@ class Heap {
   // start.
   Object* weak_object_to_code_table_;
 
+  // List of encountered weak collections (JSWeakMap and JSWeakSet) during
+  // marking. It is initialized during marking, destroyed after marking and
+  // contains Smi(0) while marking is not active.
+  Object* encountered_weak_collections_;
+
   StoreBufferRebuilder store_buffer_rebuilder_;
 
   struct StringTypeTable {

src/mark-compact.cc

@@ -51,7 +51,6 @@ MarkCompactCollector::MarkCompactCollector(Heap* heap) :  // NOLINT
       migration_slots_buffer_(NULL),
       heap_(heap),
       code_flusher_(NULL),
-      encountered_weak_collections_(NULL),
       have_code_to_deoptimize_(false) { }
 
 #ifdef VERIFY_HEAP
@@ -2738,7 +2737,7 @@ void MarkCompactCollector::ClearNonLiveDependentCode(DependentCode* entries) {
 
 void MarkCompactCollector::ProcessWeakCollections() {
   GCTracer::Scope gc_scope(tracer_, GCTracer::Scope::MC_WEAKCOLLECTION_PROCESS);
-  Object* weak_collection_obj = encountered_weak_collections();
+  Object* weak_collection_obj = heap()->encountered_weak_collections();
   while (weak_collection_obj != Smi::FromInt(0)) {
     JSWeakCollection* weak_collection =
         reinterpret_cast<JSWeakCollection*>(weak_collection_obj);
@@ -2765,7 +2764,7 @@ void MarkCompactCollector::ProcessWeakCollections() {
 
 void MarkCompactCollector::ClearWeakCollections() {
   GCTracer::Scope gc_scope(tracer_, GCTracer::Scope::MC_WEAKCOLLECTION_CLEAR);
-  Object* weak_collection_obj = encountered_weak_collections();
+  Object* weak_collection_obj = heap()->encountered_weak_collections();
   while (weak_collection_obj != Smi::FromInt(0)) {
     JSWeakCollection* weak_collection =
         reinterpret_cast<JSWeakCollection*>(weak_collection_obj);
@@ -2782,7 +2781,7 @@ void MarkCompactCollector::ClearWeakCollections() {
     weak_collection_obj = weak_collection->next();
     weak_collection->set_next(heap()->undefined_value());
   }
-  set_encountered_weak_collections(Smi::FromInt(0));
+  heap()->set_encountered_weak_collections(Smi::FromInt(0));
 }
 
 

src/mark-compact.h

@@ -649,13 +649,6 @@ class MarkCompactCollector {
 
   bool TryPromoteObject(HeapObject* object, int object_size);
 
-  inline Object* encountered_weak_collections() {
-    return encountered_weak_collections_;
-  }
-  inline void set_encountered_weak_collections(Object* weak_collection) {
-    encountered_weak_collections_ = weak_collection;
-  }
-
   void InvalidateCode(Code* code);
 
   void ClearMarkbits();
@@ -913,7 +906,6 @@ class MarkCompactCollector {
   Heap* heap_;
   MarkingDeque marking_deque_;
   CodeFlusher* code_flusher_;
-  Object* encountered_weak_collections_;
   bool have_code_to_deoptimize_;
 
   List<Page*> evacuation_candidates_;

src/objects-visiting-inl.h

@@ -402,12 +402,11 @@ void StaticMarkingVisitor<StaticVisitor>::VisitWeakCollection(
   Heap* heap = map->GetHeap();
   JSWeakCollection* weak_collection =
       reinterpret_cast<JSWeakCollection*>(object);
-  MarkCompactCollector* collector = heap->mark_compact_collector();
 
   // Enqueue weak collection in linked list of encountered weak collections.
   if (weak_collection->next() == heap->undefined_value()) {
-    weak_collection->set_next(collector->encountered_weak_collections());
-    collector->set_encountered_weak_collections(weak_collection);
+    weak_collection->set_next(heap->encountered_weak_collections());
+    heap->set_encountered_weak_collections(weak_collection);
   }
 
   // Skip visiting the backing hash table containing the mappings and the