--- old/src/share/vm/memory/heap.hpp	2014-02-04 16:00:32.106625771 +0100
+++ new/src/share/vm/memory/heap.hpp	2014-02-04 16:00:31.958625773 +0100
@@ -93,23 +93,26 @@
   FreeBlock*   _freelist;
   size_t       _freelist_segments;               // No. of segments in freelist
 
+  enum { free_sentinel = 0xFF };
+
   // Helper functions
   size_t   size_to_segments(size_t size) const { return (size + _segment_size - 1) >> _log2_segment_size; }
   size_t   segments_to_size(size_t number_of_segments) const { return number_of_segments << _log2_segment_size; }
 
   size_t   segment_for(void* p) const            { return ((char*)p - _memory.low()) >> _log2_segment_size; }
+  bool     is_segment_unused(int val) const      { return val == free_sentinel; }
   HeapBlock* block_at(size_t i) const            { return (HeapBlock*)(_memory.low() + (i << _log2_segment_size)); }
 
   void  mark_segmap_as_free(size_t beg, size_t end);
   void  mark_segmap_as_used(size_t beg, size_t end);
 
   // Freelist management helpers
-  FreeBlock* following_block(FreeBlock *b);
+  FreeBlock* following_block(FreeBlock* b);
   void insert_after(FreeBlock* a, FreeBlock* b);
-  void merge_right (FreeBlock* a);
+  bool merge_right (FreeBlock* a);
 
   // Toplevel freelist management
-  void add_to_freelist(HeapBlock *b);
+  void add_to_freelist(HeapBlock* b);
   FreeBlock* search_freelist(size_t length, bool is_critical);
 
   // Iteration helpers
@@ -120,20 +123,19 @@
 
   // to perform additional actions on creation of executable code
   void on_code_mapping(char* base, size_t size);
+  void clear();                                 // clears all heap contents
+
 
  public:
   CodeHeap();
 
   // Heap extents
   bool  reserve(size_t reserved_size, size_t committed_size, size_t segment_size);
-  void  release();                               // releases all allocated memory
-  bool  expand_by(size_t size);                  // expands commited memory by size
-  void  shrink_by(size_t size);                  // shrinks commited memory by size
-  void  clear();                                 // clears all heap contents
+  bool  expand_by(size_t size);                  // expands committed memory by size
 
   // Memory allocation
   void* allocate  (size_t size, bool is_critical);  // allocates a block of size or returns NULL
-  void  deallocate(void* p);                     // deallocates a block
+  void  deallocate(void* p);                        // deallocates a block
 
   // Attributes
   char* low_boundary() const                     { return _memory.low_boundary (); }