New GC related APIs: Implicit references.

include/v8.h

Index: include/v8.h
diff --git a/include/v8.h b/include/v8.h
index b84c730d505549d24b36749d69a73487354318be..2bb0bf4e58e2ce148f821bab0cf914fbe36503fc 100644
--- a/include/v8.h
+++ b/include/v8.h
@@ -3543,6 +3543,11 @@ class V8EXPORT V8 {
                                     UniqueId id,
                                     RetainedObjectInfo* info);
 
+  static void SetObjectGroupRepresentativeObject(

[Michael Starzinger, 2013/04/16 10:42:16]

Can we add a short comment to this method that mentions this is used in
conjunction with implicit references? Also how about naming this just
"SetObjectGroupRepresentative()", I'll leave that up to you and Sven?

[marja, 2013/04/16 12:28:37]

Done.

+      Isolate* isolate,
+      UniqueId id,
+      const Persistent<Object>& object);
+
   /**
    * Allows the host application to declare implicit references between
    * the objects: if |parent| is alive, all |children| are alive too.
@@ -3550,11 +3555,23 @@ class V8EXPORT V8 {
    * are removed.  It is intended to be used in the before-garbage-collection
    * callback function.
    */
+  // TODO(marja): Deprecate AddImplicitReferences. Use
+  // SetObjectGroupRepresentativeObject and 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. */

[Michael Starzinger, 2013/04/16 10:42:16]

nit: Close comment on next line.

[marja, 2013/04/16 12:28:37]

Done.

+  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.