diff -r fd16c54261b3 -r 489c9b5090e2 hotspot/src/share/vm/memory/filemap.hpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/src/share/vm/memory/filemap.hpp	Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,139 @@
+/*
+ * Copyright 2003-2006 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.
+ *
+ */
+
+// Layout of the file:
+//  header: dump of archive instance plus versioning info, datestamp, etc.
+//   [magic # = 0xF00BABA2]
+//  ... padding to align on page-boundary
+//  read-write space from CompactingPermGenGen
+//  read-only space from CompactingPermGenGen
+//  misc data (block offset table, string table, symbols, dictionary, etc.)
+//  tag(666)
+
+static const int JVM_SHARED_JARS_MAX = 128;
+static const int JVM_SPACENAME_MAX = 128;
+static const int JVM_IDENT_MAX = 256;
+static const int JVM_ARCH_MAX = 12;
+
+
+
+class FileMapInfo : public CHeapObj {
+private:
+  enum {
+    _invalid_version = -1,
+    _current_version = 1
+  };
+
+  bool  _file_open;
+  int   _fd;
+  long  _file_offset;
+
+  // FileMapHeader describes the shared space data in the file to be
+  // mapped.  This structure gets written to a file.  It is not a class, so
+  // that the compilers don't add any compiler-private data to it.
+
+  struct FileMapHeader {
+    int    _magic;                    // identify file type.
+    int    _version;                  // (from enum, above.)
+    size_t _alignment;                // how shared archive should be aligned
+
+    struct space_info {
+      int    _file_offset;   // sizeof(this) rounded to vm page size
+      char*  _base;          // copy-on-write base address
+      size_t _capacity;      // for validity checking
+      size_t _used;          // for setting space top on read
+      bool   _read_only;     // read only space?
+      bool   _allow_exec;    // executable code in space?
+    } _space[CompactingPermGenGen::n_regions];
+
+    // The following fields are all sanity checks for whether this archive
+    // will function correctly with this JVM and the bootclasspath it's
+    // invoked with.
+    char  _arch[JVM_ARCH_MAX];            // architecture
+    char  _jvm_ident[JVM_IDENT_MAX];      // identifier for jvm
+    int   _num_jars;              // Number of jars in bootclasspath
+
+    // Per jar file data:  timestamp, size.
+
+    struct {
+      time_t _timestamp;          // jar timestamp.
+      long   _filesize;           // jar file size.
+    } _jar[JVM_SHARED_JARS_MAX];
+  } _header;
+  const char* _full_path;
+
+  static FileMapInfo* _current_info;
+
+  bool  init_from_file(int fd);
+  void  align_file_position();
+
+public:
+  FileMapInfo() {
+    _file_offset = 0;
+    _file_open = false;
+    _header._version = _invalid_version;
+  }
+
+  static int current_version()        { return _current_version; }
+  void   populate_header(size_t alignment);
+  bool   validate();
+  void   invalidate();
+  int    version()                    { return _header._version; }
+  size_t alignment()                  { return _header._alignment; }
+  size_t space_capacity(int i)        { return _header._space[i]._capacity; }
+  char*  region_base(int i)           { return _header._space[i]._base; }
+  struct FileMapHeader* header()      { return &_header; }
+
+  static void set_current_info(FileMapInfo* info)  { _current_info = info; }
+  static FileMapInfo* current_info()  { return _current_info; }
+  static void assert_mark(bool check);
+
+  // File manipulation.
+  bool  initialize();
+  bool  open_for_read();
+  void  open_for_write();
+  void  write_header();
+  void  write_space(int i, CompactibleSpace* space, bool read_only);
+  void  write_region(int region, char* base, size_t size,
+                     size_t capacity, bool read_only, bool allow_exec);
+  void  write_bytes(const void* buffer, int count);
+  void  write_bytes_aligned(const void* buffer, int count);
+  bool  map_space(int i, ReservedSpace rs, ContiguousSpace *space);
+  char* map_region(int i, ReservedSpace rs);
+  char* map_region(int i, bool address_must_match);
+  void  unmap_region(int i);
+  void  close();
+  bool  is_open() { return _file_open; }
+
+  // JVM/TI RedefineClasses() support:
+  // Remap the shared readonly space to shared readwrite, private.
+  bool  remap_shared_readonly_as_readwrite();
+
+  // Errors.
+  static void fail_stop(const char *msg, ...);
+  void fail_continue(const char *msg, ...);
+
+  // Return true if given address is in the mapped shared space.
+  bool is_in_shared_space(const void* p);
+};