[WIP] New GC related APIs.

src/global-handles.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 10 matching lines @@
 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 #ifndef V8_GLOBAL_HANDLES_H_
 #define V8_GLOBAL_HANDLES_H_
 
+#include "../include/v8.h"
 #include "../include/v8-profiler.h"
 
 #include "list.h"
 
 namespace v8 {
 namespace internal {
 
 // Structure for tracking global handles.
 // A single list keeps all the allocated global handles.
 // Destroyed handles stay in the list but is added to the free list.
 // At GC the destroyed global handles are removed from the free list
 // and deallocated.
 
 // 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 ObjectGroupConnection {
+  ObjectGroupConnection(UniqueId id, Object** object)
+      : id(id), object(object) {}
+
+  bool operator==(const ObjectGroupConnection& other) const {
+    return id == other.id;
   }
 
-  void Dispose() {
-    if (info_ != NULL) info_->Dispose();
-    free(this);
+  bool operator<(const ObjectGroupConnection& other) const {
+    return id < other.id;
   }
 
-  size_t length_;
-  v8::RetainedObjectInfo* info_;
-  Object** objects_[1];  // Variable sized array.
-
- private:
-  void* operator new(size_t size);
-  void operator delete(void* p);
-  ~ObjectGroup();
-  DISALLOW_IMPLICIT_CONSTRUCTORS(ObjectGroup);
+  UniqueId id;
+  Object** object;
 };
 
 
+struct GroupRetainedObjectInfo {

[Michael Starzinger, 2013/04/10 10:54:16]

suggestion: We could call this struct either "ObjectGroupRetainerInfo" or just
"ObjectGroupInfo", thereby having a common prefix for everything related to
object groups (note that I am only talking about the internal naming, not the
API).

[marja, 2013/04/10 13:14:51]

Renamed to ObjectGroupRetainerInfo.

+  GroupRetainedObjectInfo(UniqueId id, RetainedObjectInfo* info)
+      : id(id), info(info) {}
+
+  bool operator==(const GroupRetainedObjectInfo& other) const {
+    return id == other.id;
+  }
+
+  bool operator<(const GroupRetainedObjectInfo& other) const {
+    return id < other.id;
+  }
+
+  UniqueId 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.
 class ImplicitRefGroup {
  public:
   static ImplicitRefGroup* New(HeapObject** parent,
                                Object*** children,
                                size_t length) {
     ASSERT(length > 0);
     ImplicitRefGroup* group = reinterpret_cast<ImplicitRefGroup*>(
@@ skipping 118 matching lines @@
   // can be skipped and false otherwise.
   bool IterateObjectGroups(ObjectVisitor* v, WeakSlotCallbackWithHeap can_skip);
 
   // Add an object group.
   // Should be only used in GC callback function before a collection.
   // All groups are destroyed after a garbage collection.
   void AddObjectGroup(Object*** handles,
                       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,

[Michael Starzinger, 2013/04/10 10:54:16]

nit: Fits into one line.

[marja, 2013/04/10 13:14:51]

Done.

+                        UniqueId id);
+
+  void SetRetainedObjectInfo(UniqueId id,

[Michael Starzinger, 2013/04/10 10:54:16]

nit: Fits into one line.

[marja, 2013/04/10 13:14:51]

Done.

+                             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.
   void AddImplicitReferences(HeapObject** parent,
                              Object*** children,
                              size_t length);
 
-  // Returns the object groups.
-  List<ObjectGroup*>* object_groups() { return &object_groups_; }
+  List<ObjectGroupConnection>* object_groups() {
+    return &object_groups_;
+  }
+
+  List<GroupRetainedObjectInfo>* retained_object_infos() {
+    return &retained_object_infos_;
+  }
 
   // Returns the implicit references' groups.
   List<ImplicitRefGroup*>* implicit_ref_groups() {
     return &implicit_ref_groups_;
   }
 
   // Remove bags, this should only happen after GC.
   void RemoveObjectGroups();
   void RemoveImplicitRefGroups();
 
@@ skipping 28 matching lines @@
 
   // Free list of nodes.
   Node* first_free_;
 
   // Contains all nodes holding new space objects. Note: when the list
   // is accessed, some of the objects may have been promoted already.
   List<Node*> new_space_nodes_;
 
   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;
 
   DISALLOW_COPY_AND_ASSIGN(GlobalHandles);
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_GLOBAL_HANDLES_H_