--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/share/vm/memory/heap.hpp	Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,161 @@
+/*
+ * Copyright 1997-2006 Sun Microsystems, Inc.  All Rights Reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ *
+ */
+
+// Blocks
+
+class HeapBlock VALUE_OBJ_CLASS_SPEC {
+  friend class VMStructs;
+
+ public:
+  struct Header {
+    size_t  _length;                             // the length in segments
+    bool    _used;                               // Used bit
+  };
+
+ protected:
+  union {
+    Header _header;
+    int64_t _padding[ (sizeof(Header) + sizeof(int64_t)-1) / sizeof(int64_t) ];
+                        // pad to 0 mod 8
+  };
+
+ public:
+  // Initialization
+  void initialize(size_t length)                 { _header._length = length; set_used(); }
+
+  // Accessors
+  void* allocated_space() const                  { return (void*)(this + 1); }
+  size_t length() const                          { return _header._length; }
+
+  // Used/free
+  void set_used()                                { _header._used = true; }
+  void set_free()                                { _header._used = false; }
+  bool free()                                    { return !_header._used; }
+};
+
+class FreeBlock: public HeapBlock {
+  friend class VMStructs;
+ protected:
+  FreeBlock* _link;
+
+ public:
+  // Initialization
+  void initialize(size_t length)             { HeapBlock::initialize(length); _link= NULL; }
+
+  // Merging
+  void set_length(size_t l)                  { _header._length = l; }
+
+  // Accessors
+  FreeBlock* link() const                    { return _link; }
+  void set_link(FreeBlock* link)             { _link = link; }
+};
+
+class CodeHeap : public CHeapObj {
+  friend class VMStructs;
+ private:
+  VirtualSpace _memory;                          // the memory holding the blocks
+  VirtualSpace _segmap;                          // the memory holding the segment map
+
+  size_t       _number_of_committed_segments;
+  size_t       _number_of_reserved_segments;
+  size_t       _segment_size;
+  int          _log2_segment_size;
+
+  size_t       _next_segment;
+
+  FreeBlock*   _freelist;
+  size_t       _free_segments;                   // No. of segments in freelist
+
+  // Helper functions
+  size_t   number_of_segments(size_t size) const { return (size + _segment_size - 1) >> _log2_segment_size; }
+  size_t   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; }
+  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);
+  void insert_after(FreeBlock* a, FreeBlock* b);
+  void merge_right (FreeBlock* a);
+
+  // Toplevel freelist management
+  void add_to_freelist(HeapBlock *b);
+  FreeBlock* search_freelist(size_t length);
+
+  // Iteration helpers
+  void*      next_free(HeapBlock* b) const;
+  HeapBlock* first_block() const;
+  HeapBlock* next_block(HeapBlock* b) const;
+  HeapBlock* block_start(void* p) const;
+
+  // to perform additional actions on creation of executable code
+  void on_code_mapping(char* base, size_t size);
+
+ 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
+
+  // Memory allocation
+  void* allocate  (size_t size);                 // allocates a block of size or returns NULL
+  void  deallocate(void* p);                     // deallocates a block
+
+  // Attributes
+  void*  begin() const                           { return _memory.low (); }
+  void*  end() const                             { return _memory.high(); }
+  bool   contains(void* p) const                 { return begin() <= p && p < end(); }
+  void*  find_start(void* p) const;              // returns the block containing p or NULL
+  size_t alignment_unit() const;                 // alignment of any block
+  size_t alignment_offset() const;               // offset of first byte of any block, within the enclosing alignment unit
+  static size_t header_size();                   // returns the header size for each heap block
+
+  // Returns reserved area high and low addresses
+  char *low_boundary() const                     { return _memory.low_boundary (); }
+  char *high_boundary() const                    { return _memory.high_boundary(); }
+
+  // Iteration
+
+  // returns the first block or NULL
+  void* first() const       { return next_free(first_block()); }
+  // returns the next block given a block p or NULL
+  void* next(void* p) const { return next_free(next_block(block_start(p))); }
+
+  // Statistics
+  size_t capacity() const;
+  size_t max_capacity() const;
+  size_t allocated_capacity() const;
+  size_t unallocated_capacity() const            { return max_capacity() - allocated_capacity(); }
+
+  // Debugging
+  void verify();
+  void print()  PRODUCT_RETURN;
+};