New GC APIs, try 2.

include/v8.h

 // 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 127 matching lines @@
 
 namespace internal {
 class Arguments;
 class Heap;
 class HeapObject;
 class Isolate;
 class Object;
 }
 
 
+/**
+ * General purpose unique identifier.
+ */
+class UniqueId {
+ public:
+  explicit UniqueId(intptr_t data)
+      : data_(data) {}
+
+  bool operator==(const UniqueId& other) const {
+    return data_ == other.data_;
+  }
+
+  bool operator!=(const UniqueId& other) const {
+    return data_ != other.data_;
+  }
+
+  bool operator<(const UniqueId& other) const {
+    return data_ < other.data_;
+  }
+
+ private:
+  intptr_t data_;
+};
+
+
 // --- Weak Handles ---
 
 
 /**
  * A weak reference callback function.
  *
  * This callback should either explicitly invoke Dispose on |object| if
  * V8 wrapper is not needed anymore, or 'revive' it by invocation of MakeWeak.
  *
  * \param object the weak global object to be reclaimed by the garbage collector
@@ skipping 2945 matching lines @@
 
   /**
    * Returns CPU profiler for this isolate. Will return NULL until the isolate
    * is initialized.
    */
   CpuProfiler* GetCpuProfiler();
 
   /** Returns the context that is on the top of the stack. */
   Local<Context> GetCurrentContext();
 
+  /**
+   * Allows the host application to group objects together. If one
+   * object in the group is alive, all objects in the group are alive.
+   * After each garbage collection, object groups are removed. It is
+   * intended to be used in the before-garbage-collection callback
+   * function, for instance to simulate DOM tree connections among JS
+   * wrapper objects. Object groups for all dependent handles need to
+   * be provided for kGCTypeMarkSweepCompact collections, for all other
+   * garbage collection types it is sufficient to provide object groups
+   * for partially dependent handles only.
+   */
+  void SetObjectGroupId(const Persistent<Value>& object,
+                        UniqueId id);
+
+  /**
+   * Allows the host application to declare implicit references. If the objects
+   * of the object group are alive, the children are alive too. After each
+   * garbage collection, all implicit references are removed. It is intended to
+   * be used in the before-garbage-collection callback function.
+   */
+  void AddImplicitReference(UniqueId id,

[yurys, 2013/04/22 14:39:54]

Method name is a bit confusing. May be SetReferenceFromGroup? SetObjectGroupId
actually adds bidirectional reference while AddImplicitReference adds
unidirectional one. Method names should probably reflect this.

[marja, 2013/04/23 12:00:05]

Done.

+                            const Persistent<Value>& object);
+
  private:
   Isolate();
   Isolate(const Isolate&);
   ~Isolate();
   Isolate& operator=(const Isolate&);
   void* operator new(size_t size);
   void operator delete(void*, size_t);
 };
 
 
@@ skipping 384 matching lines @@
    * object in the group is alive, all objects in the group are alive.
    * After each garbage collection, object groups are removed. It is
    * intended to be used in the before-garbage-collection callback
    * function, for instance to simulate DOM tree connections among JS
    * wrapper objects. Object groups for all dependent handles need to
    * be provided for kGCTypeMarkSweepCompact collections, for all other
    * garbage collection types it is sufficient to provide object groups
    * for partially dependent handles only.
    * See v8-profiler.h for RetainedObjectInfo interface description.
    */
+  // TODO(marja): deprecate AddObjectGroup. Use Isolate::SetObjectGroupId and
+  // HeapProfiler::SetRetainedObjectInfo instead.
   static void AddObjectGroup(Persistent<Value>* objects,
                              size_t length,
                              RetainedObjectInfo* info = NULL);
   static void AddObjectGroup(Isolate* isolate,
                              Persistent<Value>* objects,
                              size_t length,
                              RetainedObjectInfo* info = NULL);
 
   /**
    * Allows the host application to declare implicit references between
    * the objects: if |parent| is alive, all |children| are alive too.
    * After each garbage collection, all implicit references
    * are removed.  It is intended to be used in the before-garbage-collection
    * callback function.
    */
+  // TODO(marja): Deprecate AddImplicitReferences. Use
+  // Isolate::AddImplicitReference instead.
   static void AddImplicitReferences(Persistent<Object> parent,
                                     Persistent<Value>* children,
                                     size_t length);
 
   /**
    * Initializes from snapshot if possible. Otherwise, attempts to
    * initialize from scratch.  This function is called implicitly if
    * you use the API without calling it first.
    */
   static bool Initialize();
@@ skipping 1595 matching lines @@
 
 
 }  // namespace v8
 
 
 #undef V8EXPORT
 #undef TYPE_CHECK
 
 
 #endif  // V8_H_