- Introduce histograms collecting data about the number of set remembered set...

src/heap.h

 // 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 648 matching lines @@
   static void IterateRoots(ObjectVisitor* v);
   // Iterates over all strong roots in the heap.
   static void IterateStrongRoots(ObjectVisitor* v);
 
   // Iterates remembered set of an old space.
   static void IterateRSet(PagedSpace* space, ObjectSlotCallback callback);
 
   // Iterates a range of remembered set addresses starting with rset_start
   // corresponding to the range of allocated pointers
   // [object_start, object_end).
-  static void IterateRSetRange(Address object_start,
-                               Address object_end,
-                               Address rset_start,
-                               ObjectSlotCallback copy_object_func);
+  // Returns the number of bits that were set.
+  static int IterateRSetRange(Address object_start,
+                              Address object_end,
+                              Address rset_start,
+                              ObjectSlotCallback copy_object_func);
 
   // Returns whether the object resides in new space.
   static inline bool InNewSpace(Object* object);
   static inline bool InFromSpace(Object* object);
   static inline bool InToSpace(Object* object);
 
   // Checks whether an address/object in the heap (including auxiliary
   // area and unused area).
   static bool Contains(Address addr);
   static bool Contains(HeapObject* value);
@@ skipping 623 matching lines @@
   int marked_count_;
 
   // The count from the end of the previous full GC.  Will be zero if there
   // was no previous full GC.
   int previous_marked_count_;
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_HEAP_H_