--- old/src/share/vm/utilities/bitMap.hpp	2014-11-06 00:05:10.298893863 +0300
+++ new/src/share/vm/utilities/bitMap.hpp	2014-11-06 00:05:10.246893861 +0300
@@ -36,6 +36,7 @@
 
 class BitMap VALUE_OBJ_CLASS_SPEC {
   friend class BitMap2D;
+  friend class BitMapIterator;
 
  public:
   typedef size_t idx_t;         // Type used for bit and word indices.
@@ -115,7 +116,7 @@
 
   // Constructs a bitmap with no map, and size 0.
   BitMap() : _map(NULL), _size(0), _map_allocator(false) {}
-
+ 
   // Constructs a bitmap with the given map and size.
   BitMap(bm_word_t* map, idx_t size_in_bits);
 
@@ -164,6 +165,10 @@
   inline void set_bit(idx_t bit);
   inline void clear_bit(idx_t bit);
 
+   // Set or clear the specified bit with result
+  inline bool set_bit_with_result(idx_t bit);
+  inline bool clear_bit_with_result(idx_t bit);
+
   // Atomically set or clear the specified bit.
   inline bool par_set_bit(idx_t bit);
   inline bool par_clear_bit(idx_t bit);
@@ -272,6 +277,39 @@
 #endif
 };
 
+class BitMapIterator VALUE_OBJ_CLASS_SPEC {
+  friend class BitMap;
+   
+  typedef BitMap::idx_t idx_t;          // Type used for bit and word indices.
+  typedef BitMap::bm_word_t bm_word_t;  // Element type of array that
+                                        // represents the bitmap.
+  
+  // We walk over the bits in a word in chunks of size window_size.
+  enum { window_size = 8,
+         window_mask = right_n_bits(window_size),
+         table_size  = (1 << window_size) };
+
+  // For an integer of length window_size, what is the first set bit?
+  static const uint8_t _first_bit[table_size];
+
+  // For an integer of length window_size, what is the first set bit?
+  static const uint8_t _second_bit[table_size];
+
+  
+  BitMap* _bs;
+  bm_word_t _current;
+  idx_t   _value;
+  idx_t   _last_word;
+  idx_t   _max_word;
+
+ public:
+  BitMapIterator(BitMap* bs);
+
+  // Return the next element of the set.  Return 0 when done.
+
+  uint next();
+};
+
 // Convenience class wrapping BitMap which provides multiple bits per slot.
 class BitMap2D VALUE_OBJ_CLASS_SPEC {
  public: