source: mainline/uspace/lib/libc/include/limits.h@ aadf01e

lfn serial ticket/834-toolchain-update topic/msim-upgrade topic/simplify-dev-export
Last change on this file since aadf01e was ed903174, checked in by Martin Decky <martin@…>, 15 years ago

implement support for 64bit file offsets

  • the libc API is a small deviation from standard, but we have no reason to keep a strict backward compatibility with ancient code so far
    • the basic signed 64bit offset type is called off64_t
      • lseek() and fseek() take off64_t arguments (since the argument represents a relative offset)
      • ftell() returns off64_t values (since it is a wrapper of lseek())
      • vfs_seek() implementation supports negative offsets when SEEK_CUR and SEEK_END is used
    • aoff64_t is used for internal unsigned representation of sizes (in bytes, blocks, etc.) and absolute offsets
      • mmap() and ftruncate() take aoff64_t arguments (since the full range of the absolute file offset should be used here)
      • struct stat stores the file size as aoff64_t
    • in both cases the explicit range of the types shown in the names is helpful for proper filesystem and IPC interaction
    • note: size_t should be used only for representing in-memory sizes and offsets, not device and file-related information, and vice versa
      • the code base still needs a thorough revision with respect to this rule
    • PRIdOFF64 and PRIuOFF64 can be used for printing the offsets
  • VFS_OUT_LOOKUP returns the 64bit file size in two IPC arguments
    • since all 5 IPC arguments have already been taken, the fs_handle is returned as the return value (fs_handle has only 16 bits, thus the return value can be used for both indicating errors as negative values and returning positive handles)
  • VFS_OUT_READ and VFS_OUT_WRITE use aoff64_t absolute offsets split into two IPC arguments

replace bn_t with aoff64_t as a generic 64bit bytes/block counter type

note: filesystem drivers need to be revised with respect to make sure that all out-of-range checks are correct (especially w.r.t. file and block offsets)
  • Property mode set to 100644
File size: 2.4 KB
Line 
1/*
2 * Copyright (c) 2006 Josef Cejka
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 *
9 * - Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * - Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 * - The name of the author may not be used to endorse or promote products
15 * derived from this software without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 */
28
29/** @addtogroup libc
30 * @{
31 */
32/** @file
33 */
34
35#ifndef LIBC_LIMITS_H_
36#define LIBC_LIMITS_H_
37
38#include <stdint.h>
39#include <libarch/limits.h>
40
41/* char */
42#define SCHAR_MIN MIN_INT8
43#define SCHAR_MAX MAX_INT8
44#define UCHAR_MIN MIN_UINT8
45#define UCHAR_MAX MAX_UINT8
46
47#ifdef __CHAR_UNSIGNED__
48 #define CHAR_MIN UCHAR_MIN
49 #define CHAR_MAX UCHAR_MAX
50#else
51 #define CHAR_MIN SCHAR_MIN
52 #define CHAR_MAX SCHAR_MAX
53#endif
54
55/* short int */
56#define SHRT_MIN MIN_INT16
57#define SHRT_MAX MAX_INT16
58#define USHRT_MIN MIN_UINT16
59#define USHRT_MAX MAX_UINT16
60
61/* int */
62#define INT_MIN MIN_INT32
63#define INT_MAX MAX_INT32
64#define UINT_MIN MIN_UINT32
65#define UINT_MAX MAX_UINT32
66
67/* long long int */
68#define LLONG_MIN MIN_INT64
69#define LLONG_MAX MAX_INT64
70#define ULLONG_MIN MIN_UINT64
71#define ULLONG_MAX MAX_UINT64
72
73/* off64_t */
74#define OFF64_MIN MIN_INT64
75#define OFF64_MAX MAX_INT64
76
77/* aoff64_t */
78#define AOFF64_MIN MIN_UINT64
79#define AOFF64_MAX MAX_UINT64
80
81#endif
82
83/** @}
84 */
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