[WIP] New GC related APIs.

src/global-handles.h

Index: src/global-handles.h
diff --git a/src/global-handles.h b/src/global-handles.h
index 990014467cea5157612eed91400490ee3d6367d5..55d41fac501b88ff30a007f729a91a7242a98e95 100644
--- a/src/global-handles.h
+++ b/src/global-handles.h
@@ -44,37 +44,52 @@ namespace internal {
 // An object group is treated like a single JS object: if one of object in
 // the group is alive, all objects in the same group are considered alive.
 // An object group is used to simulate object relationship in a DOM tree.
-class ObjectGroup {
- public:
-  static ObjectGroup* New(Object*** handles,
-                          size_t length,
-                          v8::RetainedObjectInfo* info) {
-    ASSERT(length > 0);
-    ObjectGroup* group = reinterpret_cast<ObjectGroup*>(
-        malloc(OFFSET_OF(ObjectGroup, objects_[length])));
-    group->length_ = length;
-    group->info_ = info;
-    CopyWords(group->objects_, handles, static_cast<int>(length));
-    return group;
-  }
+struct ObjectGroup {
+  ObjectGroup()
+      : info(NULL) {}
 
-  void Dispose() {
-    if (info_ != NULL) info_->Dispose();
-    free(this);
+  ~ObjectGroup();
+
+  v8::RetainedObjectInfo* info;
+  List<Object**> objects;
+};
+
+
+struct ObjectGroupConnection {
+  ObjectGroupConnection(void* id, Object** object)
+      : id(id), object(object) {}
+
+  bool operator==(const ObjectGroupConnection& other) const {
+    return id == other.id;
   }
 
-  size_t length_;
-  v8::RetainedObjectInfo* info_;
-  Object** objects_[1];  // Variable sized array.
+  bool operator<(const ObjectGroupConnection& other) const {
+    return id < other.id;
+  }
 
- private:
-  void* operator new(size_t size);
-  void operator delete(void* p);
-  ~ObjectGroup();
-  DISALLOW_IMPLICIT_CONSTRUCTORS(ObjectGroup);
+  void* id;
+  Object** object;
 };
 
 
+struct GroupRetainedObjectInfo {
+  GroupRetainedObjectInfo(void* id, RetainedObjectInfo* info)
+      : id(id), info(info) {}
+
+  ~GroupRetainedObjectInfo();
+
+  bool operator==(const GroupRetainedObjectInfo& other) const {
+    return id == other.id;
+  }
+
+  bool operator<(const GroupRetainedObjectInfo& other) const {
+    return id < other.id;
+  }
+
+  void* id;
+  RetainedObjectInfo* info;
+};
+
 // An implicit references group consists of two parts: a parent object and
 // a list of children objects.  If the parent is alive, all the children
 // are alive too.
@@ -213,6 +228,15 @@ class GlobalHandles {
                       size_t length,
                       v8::RetainedObjectInfo* info);
 
+  // Associates handle with the object group represented by id.
+  // Should be only used in GC callback function before a collection.
+  // All groups are destroyed after a garbage collection.
+  void SetObjectGroupId(Object** handle,
+                        void* id);
+
+  void SetRetainedObjectInfo(void* id,
+                             RetainedObjectInfo* info = NULL);
+
   // Add an implicit references' group.
   // Should be only used in GC callback function before a collection.
   // All groups are destroyed after a mark-compact collection.
@@ -220,8 +244,10 @@ class GlobalHandles {
                              Object*** children,
                              size_t length);
 
-  // Returns the object groups.
-  List<ObjectGroup*>* object_groups() { return &object_groups_; }
+  // Returns the object groups. Caller takes ownership of the list, and the
+  // ObjectGroup pointers in it, and the RetainedObjectInfo pointers in the
+  // object groups.
+  List<ObjectGroup*>* object_groups();
 
   // Returns the implicit references' groups.
   List<ImplicitRefGroup*>* implicit_ref_groups() {
@@ -270,7 +296,8 @@ class GlobalHandles {
 
   int post_gc_processing_count_;
 
-  List<ObjectGroup*> object_groups_;
+  List<ObjectGroupConnection>* object_groups_;
+  List<GroupRetainedObjectInfo> retained_object_infos_;
   List<ImplicitRefGroup*> implicit_ref_groups_;
 
   friend class Isolate;