Improve mark-compact object grouping interface.

src/mark-compact.cc

 // Copyright 2006-2008 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 546 matching lines @@
 
   // There may be overflowed objects in the heap.  Visit them now.
   while (marking_stack.overflowed()) {
     RefillMarkingStack();
     EmptyMarkingStack(visitor->stack_visitor());
   }
 }
 
 
 void MarkCompactCollector::MarkObjectGroups() {
-  List<ObjectGroup*>& object_groups = GlobalHandles::ObjectGroups();
+  List<ObjectGroup*>* object_groups = GlobalHandles::ObjectGroups();
 
-  for (int i = 0; i < object_groups.length(); i++) {
-    ObjectGroup* entry = object_groups[i];
+  for (int i = 0; i < object_groups->length(); i++) {
+    ObjectGroup* entry = object_groups->at(i);
     if (entry == NULL) continue;
 
     List<Object**>& objects = entry->objects_;
     bool group_marked = false;
     for (int j = 0; j < objects.length(); j++) {
       Object* object = *objects[j];
       if (object->IsHeapObject() && HeapObject::cast(object)->IsMarked()) {
         group_marked = true;
         break;
       }
     }
 
     if (!group_marked) continue;
 
     // An object in the group is marked, so mark as gray all white heap
     // objects in the group.
     for (int j = 0; j < objects.length(); ++j) {
       if ((*objects[j])->IsHeapObject()) {
         MarkObject(HeapObject::cast(*objects[j]));
       }
     }
     // Once the entire group has been colored gray, set the object group
     // to NULL so it won't be processed again.
-    delete object_groups[i];
-    object_groups[i] = NULL;
+    delete object_groups->at(i);
+    object_groups->at(i) = NULL;
   }
 }
 
 
 // Mark all objects reachable from the objects on the marking stack.
 // Before: the marking stack contains zero or more heap object pointers.
 // After: the marking stack is empty, and all objects reachable from the
 // marking stack have been marked, or are overflowed in the heap.
 void MarkCompactCollector::EmptyMarkingStack(MarkingVisitor* visitor) {
   while (!marking_stack.is_empty()) {
@@ skipping 1281 matching lines @@
 
 void MarkCompactCollector::RebuildRSets() {
 #ifdef DEBUG
   ASSERT(state_ == RELOCATE_OBJECTS);
   state_ = REBUILD_RSETS;
 #endif
   Heap::RebuildRSets();
 }
 
 } }  // namespace v8::internal