filemap.hpp revision 0:a61af66fc99e
1/*
2 * Copyright 2003-2006 Sun Microsystems, Inc.  All Rights Reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
20 * CA 95054 USA or visit www.sun.com if you need additional information or
21 * have any questions.
22 *
23 */
24
25// Layout of the file:
26//  header: dump of archive instance plus versioning info, datestamp, etc.
27//   [magic # = 0xF00BABA2]
28//  ... padding to align on page-boundary
29//  read-write space from CompactingPermGenGen
30//  read-only space from CompactingPermGenGen
31//  misc data (block offset table, string table, symbols, dictionary, etc.)
32//  tag(666)
33
34static const int JVM_SHARED_JARS_MAX = 128;
35static const int JVM_SPACENAME_MAX = 128;
36static const int JVM_IDENT_MAX = 256;
37static const int JVM_ARCH_MAX = 12;
38
39
40
41class FileMapInfo : public CHeapObj {
42private:
43  enum {
44    _invalid_version = -1,
45    _current_version = 1
46  };
47
48  bool  _file_open;
49  int   _fd;
50  long  _file_offset;
51
52  // FileMapHeader describes the shared space data in the file to be
53  // mapped.  This structure gets written to a file.  It is not a class, so
54  // that the compilers don't add any compiler-private data to it.
55
56  struct FileMapHeader {
57    int    _magic;                    // identify file type.
58    int    _version;                  // (from enum, above.)
59    size_t _alignment;                // how shared archive should be aligned
60
61    struct space_info {
62      int    _file_offset;   // sizeof(this) rounded to vm page size
63      char*  _base;          // copy-on-write base address
64      size_t _capacity;      // for validity checking
65      size_t _used;          // for setting space top on read
66      bool   _read_only;     // read only space?
67      bool   _allow_exec;    // executable code in space?
68    } _space[CompactingPermGenGen::n_regions];
69
70    // The following fields are all sanity checks for whether this archive
71    // will function correctly with this JVM and the bootclasspath it's
72    // invoked with.
73    char  _arch[JVM_ARCH_MAX];            // architecture
74    char  _jvm_ident[JVM_IDENT_MAX];      // identifier for jvm
75    int   _num_jars;              // Number of jars in bootclasspath
76
77    // Per jar file data:  timestamp, size.
78
79    struct {
80      time_t _timestamp;          // jar timestamp.
81      long   _filesize;           // jar file size.
82    } _jar[JVM_SHARED_JARS_MAX];
83  } _header;
84  const char* _full_path;
85
86  static FileMapInfo* _current_info;
87
88  bool  init_from_file(int fd);
89  void  align_file_position();
90
91public:
92  FileMapInfo() {
93    _file_offset = 0;
94    _file_open = false;
95    _header._version = _invalid_version;
96  }
97
98  static int current_version()        { return _current_version; }
99  void   populate_header(size_t alignment);
100  bool   validate();
101  void   invalidate();
102  int    version()                    { return _header._version; }
103  size_t alignment()                  { return _header._alignment; }
104  size_t space_capacity(int i)        { return _header._space[i]._capacity; }
105  char*  region_base(int i)           { return _header._space[i]._base; }
106  struct FileMapHeader* header()      { return &_header; }
107
108  static void set_current_info(FileMapInfo* info)  { _current_info = info; }
109  static FileMapInfo* current_info()  { return _current_info; }
110  static void assert_mark(bool check);
111
112  // File manipulation.
113  bool  initialize();
114  bool  open_for_read();
115  void  open_for_write();
116  void  write_header();
117  void  write_space(int i, CompactibleSpace* space, bool read_only);
118  void  write_region(int region, char* base, size_t size,
119                     size_t capacity, bool read_only, bool allow_exec);
120  void  write_bytes(const void* buffer, int count);
121  void  write_bytes_aligned(const void* buffer, int count);
122  bool  map_space(int i, ReservedSpace rs, ContiguousSpace *space);
123  char* map_region(int i, ReservedSpace rs);
124  char* map_region(int i, bool address_must_match);
125  void  unmap_region(int i);
126  void  close();
127  bool  is_open() { return _file_open; }
128
129  // JVM/TI RedefineClasses() support:
130  // Remap the shared readonly space to shared readwrite, private.
131  bool  remap_shared_readonly_as_readwrite();
132
133  // Errors.
134  static void fail_stop(const char *msg, ...);
135  void fail_continue(const char *msg, ...);
136
137  // Return true if given address is in the mapped shared space.
138  bool is_in_shared_space(const void* p);
139};
140