Distinguish weak references in heap snapshots, group GC roots.

src/profile-generator.h

 // Copyright 2011 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 437 matching lines @@
 class HeapEntry;
 
 class HeapGraphEdge BASE_EMBEDDED {
  public:
   enum Type {
     kContextVariable = v8::HeapGraphEdge::kContextVariable,
     kElement = v8::HeapGraphEdge::kElement,
     kProperty = v8::HeapGraphEdge::kProperty,
     kInternal = v8::HeapGraphEdge::kInternal,
     kHidden = v8::HeapGraphEdge::kHidden,
-    kShortcut = v8::HeapGraphEdge::kShortcut
+    kShortcut = v8::HeapGraphEdge::kShortcut,
+    kWeak = v8::HeapGraphEdge::kWeak
   };
 
   HeapGraphEdge() { }
   void Init(int child_index, Type type, const char* name, HeapEntry* to);
   void Init(int child_index, Type type, int index, HeapEntry* to);
   void Init(int child_index, int index, HeapEntry* to);
 
   Type type() { return static_cast<Type>(type_); }
   int index() {
-    ASSERT(type_ == kElement || type_ == kHidden);
+    ASSERT(type_ == kElement || type_ == kHidden || type_ == kWeak);
     return index_;
   }
   const char* name() {
     ASSERT(type_ == kContextVariable
            || type_ == kProperty
            || type_ == kInternal
            || type_ == kShortcut);
     return name_;
   }
   HeapEntry* to() { return to_; }
@@ skipping 102 matching lines @@
   void SetNamedReference(HeapGraphEdge::Type type,
                          int child_index,
                          const char* name,
                          HeapEntry* entry,
                          int retainer_index);
   void SetUnidirElementReference(int child_index, int index, HeapEntry* entry);
 
   int EntrySize() { return EntriesSize(1, children_count_, retainers_count_); }
   int RetainedSize(bool exact);
 
-  void Print(int max_depth, int indent);
+  void Print(
+      const char* prefix, const char* edge_name, int max_depth, int indent);
 
   Handle<HeapObject> GetHeapObject();
 
   static int EntriesSize(int entries_count,
                          int children_count,
                          int retainers_count);
 
  private:
   HeapGraphEdge* children_arr() {
     return reinterpret_cast<HeapGraphEdge*>(this + 1);
@@ skipping 52 matching lines @@
   ~HeapSnapshot();
   void Delete();
 
   HeapSnapshotsCollection* collection() { return collection_; }
   Type type() { return type_; }
   const char* title() { return title_; }
   unsigned uid() { return uid_; }
   HeapEntry* root() { return root_entry_; }
   HeapEntry* gc_roots() { return gc_roots_entry_; }
   HeapEntry* natives_root() { return natives_root_entry_; }
+  HeapEntry* gc_subroot(int index) { return gc_subroot_entries_[index]; }
   List<HeapEntry*>* entries() { return &entries_; }
   int raw_entries_size() { return raw_entries_size_; }
 
   void AllocateEntries(
       int entries_count, int children_count, int retainers_count);
   HeapEntry* AddEntry(HeapEntry::Type type,
                       const char* name,
                       uint64_t id,
                       int size,
                       int children_count,
                       int retainers_count);
   HeapEntry* AddRootEntry(int children_count);
   HeapEntry* AddGcRootsEntry(int children_count, int retainers_count);
+  HeapEntry* AddGcSubrootEntry(int tag,
+                               int children_count,
+                               int retainers_count);
   HeapEntry* AddNativesRootEntry(int children_count, int retainers_count);
   void ClearPaint();
   HeapEntry* GetEntryById(uint64_t id);
   List<HeapEntry*>* GetSortedEntriesList();
   template<class Visitor>
   void IterateEntries(Visitor* visitor) { entries_.Iterate(visitor); }
   void SetDominatorsToSelf();
 
   void Print(int max_depth);
   void PrintEntriesSize();
 
  private:
   HeapEntry* GetNextEntryToInit();
 
   HeapSnapshotsCollection* collection_;
   Type type_;
   const char* title_;
   unsigned uid_;
   HeapEntry* root_entry_;
   HeapEntry* gc_roots_entry_;
   HeapEntry* natives_root_entry_;
+  HeapEntry* gc_subroot_entries_[VisitorSynchronization::kNumberOfSyncTags];
   char* raw_entries_;
   List<HeapEntry*> entries_;
   bool entries_sorted_;
   int raw_entries_size_;
 
   friend class HeapSnapshotTester;
 
   DISALLOW_COPY_AND_ASSIGN(HeapSnapshot);
 };
 
 
 class HeapObjectsMap {
  public:
   HeapObjectsMap();
   ~HeapObjectsMap();
 
   void SnapshotGenerationFinished();
   uint64_t FindObject(Address addr);
   void MoveObject(Address from, Address to);
 
   static uint64_t GenerateId(v8::RetainedObjectInfo* info);
+  static inline uint64_t GetNthGcSubrootId(int delta);
 
+  static const int kObjectIdStep = 2;
   static const uint64_t kInternalRootObjectId;
   static const uint64_t kGcRootsObjectId;
   static const uint64_t kNativesRootObjectId;
+  static const uint64_t kGcRootsFirstSubrootId;
   static const uint64_t kFirstAvailableObjectId;
 
  private:
   struct EntryInfo {
     explicit EntryInfo(uint64_t id) : id(id), accessed(true) { }
     EntryInfo(uint64_t id, bool accessed) : id(id), accessed(accessed) { }
     uint64_t id;
     bool accessed;
   };
 
@@ skipping 229 matching lines @@
                             int field_offset = -1);
   void SetInternalReference(HeapObject* parent_obj,
                             HeapEntry* parent,
                             int index,
                             Object* child,
                             int field_offset = -1);
   void SetHiddenReference(HeapObject* parent_obj,
                           HeapEntry* parent,
                           int index,
                           Object* child);
+  void SetWeakReference(HeapObject* parent_obj,
+                        HeapEntry* parent_entry,
+                        int index,
+                        Object* child_obj,
+                        int field_offset);
   void SetPropertyReference(HeapObject* parent_obj,
                             HeapEntry* parent,
                             String* reference_name,
                             Object* child,
                             const char* name_format_string = NULL,
                             int field_offset = -1);
   void SetPropertyShortcutReference(HeapObject* parent_obj,
                                     HeapEntry* parent,
                                     String* reference_name,
                                     Object* child);
   void SetRootShortcutReference(Object* child);
   void SetRootGcRootsReference();
-  void SetGcRootsReference(Object* child);
+  void SetGcRootsReference(VisitorSynchronization::SyncTag tag);
+  void SetGcSubrootReference(
+      VisitorSynchronization::SyncTag tag, bool is_weak, Object* child);
   void TagObject(Object* obj, const char* tag);
 
   HeapEntry* GetEntry(Object* obj);
 
+  static inline HeapObject* GetNthGcSubrootObject(int delta);
+  static inline int GetGcSubrootOrder(HeapObject* subroot);
+
   Heap* heap_;
   HeapSnapshot* snapshot_;
   HeapSnapshotsCollection* collection_;
   SnapshottingProgressReportingInterface* progress_;
   SnapshotFillerInterface* filler_;
   HeapObjectsSet objects_tags_;
 
   static HeapObject* const kGcRootsObject;
+  static HeapObject* const kFirstGcSubrootObject;
+  static HeapObject* const kLastGcSubrootObject;
 
   friend class IndexedReferencesExtractor;
+  friend class GcSubrootsEnumerator;
   friend class RootsReferencesExtractor;
 
   DISALLOW_COPY_AND_ASSIGN(V8HeapExplorer);
 };
 
 
 // An implementation of retained native objects extractor.
 class NativeObjectsExplorer : public HeapEntriesAllocator {
  public:
   NativeObjectsExplorer(HeapSnapshot* snapshot,
@@ skipping 120 matching lines @@
 
   friend class HeapSnapshotJSONSerializerEnumerator;
   friend class HeapSnapshotJSONSerializerIterator;
 
   DISALLOW_COPY_AND_ASSIGN(HeapSnapshotJSONSerializer);
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_PROFILE_GENERATOR_H_