New GC APIs, try 2.

include/v8.h

Index: include/v8.h
diff --git a/include/v8.h b/include/v8.h
index e1c020310bcd08e2cb75cd54aab7da52ab499be2..3d3c93d7e337f8867da5bb6c9c104ce8cdc0503c 100644
--- a/include/v8.h
+++ b/include/v8.h
@@ -144,6 +144,28 @@ class Isolate;
 class Object;
 }
 
+// Generic-purpose unique identifier.

[Michael Starzinger, 2013/04/22 11:34:51]

nit: Can we turn that into a Doxygen comment (i.e. double-asterisk and
multi-line). Also two empty new-lines in front of the comment.

[marja, 2013/04/22 13:49:07]

Done.

+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 ---
 
@@ -3514,6 +3536,8 @@ class V8EXPORT V8 {
    * for partially dependent handles only.
    * See v8-profiler.h for RetainedObjectInfo interface description.
    */
+  // TODO(marja): deprecate AddObjectGroup. Use SetObjectGroupId and
+  // SetRetainedObjectInfo instead.
   static void AddObjectGroup(Persistent<Value>* objects,
                              size_t length,
                              RetainedObjectInfo* info = NULL);
@@ -3522,6 +3546,14 @@ class V8EXPORT V8 {
                              size_t length,
                              RetainedObjectInfo* info = NULL);
 
+  static void SetObjectGroupId(Isolate* isolate,

[yurys, 2013/04/22 12:10:43]

Since these methods are new why not make them instance methods on Isolate?

[marja, 2013/04/22 13:49:07]

Done.

+                               const Persistent<Value>& object,
+                               UniqueId id);
+
+  static void SetRetainedObjectInfo(Isolate* isolate,

[yurys, 2013/04/22 12:05:46]

As discussed offline, this method should be on v8::HeapProfiler

[marja, 2013/04/22 13:49:07]

Done.

+                                    UniqueId id,
+                                    RetainedObjectInfo* info);
+
   /**
    * Allows the host application to declare implicit references between
    * the objects: if |parent| is alive, all |children| are alive too.
@@ -3529,11 +3561,24 @@ class V8EXPORT V8 {
    * are removed.  It is intended to be used in the before-garbage-collection
    * callback function.
    */
+  // TODO(marja): Deprecate AddImplicitReferences. Use AddImplicitReference
+  // instead.
   static void AddImplicitReferences(Persistent<Object> parent,
                                     Persistent<Value>* children,
                                     size_t length);
 
   /**
+   * Allows the host application to declare implicit references. If the
+   * representative object of the object group (identified by id) is 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.
+   */
+  static void AddImplicitReference(Isolate* isolate,
+                                   UniqueId id,
+                                   const Persistent<Value>& object);
+
+  /**
    * 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.