| 1 | /* Implement fopen_unlocked and related functions. |
| 2 | Copyright (C) 2005-2019 Free Software Foundation, Inc. |
| 3 | Written by Kaveh R. Ghazi <ghazi@caip.rutgers.edu>. |
| 4 | |
| 5 | This file is part of the libiberty library. |
| 6 | Libiberty is free software; you can redistribute it and/or |
| 7 | modify it under the terms of the GNU Library General Public |
| 8 | License as published by the Free Software Foundation; either |
| 9 | version 2 of the License, or (at your option) any later version. |
| 10 | |
| 11 | Libiberty is distributed in the hope that it will be useful, |
| 12 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 14 | Library General Public License for more details. |
| 15 | |
| 16 | You should have received a copy of the GNU Library General Public |
| 17 | License along with libiberty; see the file COPYING.LIB. If |
| 18 | not, write to the Free Software Foundation, Inc., 51 Franklin Street - Fifth Floor, |
| 19 | Boston, MA 02110-1301, USA. */ |
| 20 | |
| 21 | /* |
| 22 | |
| 23 | @deftypefn Extension void unlock_stream (FILE * @var{stream}) |
| 24 | |
| 25 | If the OS supports it, ensure that the supplied stream is setup to |
| 26 | avoid any multi-threaded locking. Otherwise leave the @code{FILE} |
| 27 | pointer unchanged. If the @var{stream} is @code{NULL} do nothing. |
| 28 | |
| 29 | @end deftypefn |
| 30 | |
| 31 | @deftypefn Extension void unlock_std_streams (void) |
| 32 | |
| 33 | If the OS supports it, ensure that the standard I/O streams, |
| 34 | @code{stdin}, @code{stdout} and @code{stderr} are setup to avoid any |
| 35 | multi-threaded locking. Otherwise do nothing. |
| 36 | |
| 37 | @end deftypefn |
| 38 | |
| 39 | @deftypefn Extension {FILE *} fopen_unlocked (const char *@var{path}, @ |
| 40 | const char * @var{mode}) |
| 41 | |
| 42 | Opens and returns a @code{FILE} pointer via @code{fopen}. If the |
| 43 | operating system supports it, ensure that the stream is setup to avoid |
| 44 | any multi-threaded locking. Otherwise return the @code{FILE} pointer |
| 45 | unchanged. |
| 46 | |
| 47 | @end deftypefn |
| 48 | |
| 49 | @deftypefn Extension {FILE *} fdopen_unlocked (int @var{fildes}, @ |
| 50 | const char * @var{mode}) |
| 51 | |
| 52 | Opens and returns a @code{FILE} pointer via @code{fdopen}. If the |
| 53 | operating system supports it, ensure that the stream is setup to avoid |
| 54 | any multi-threaded locking. Otherwise return the @code{FILE} pointer |
| 55 | unchanged. |
| 56 | |
| 57 | @end deftypefn |
| 58 | |
| 59 | @deftypefn Extension {FILE *} freopen_unlocked (const char * @var{path}, @ |
| 60 | const char * @var{mode}, FILE * @var{stream}) |
| 61 | |
| 62 | Opens and returns a @code{FILE} pointer via @code{freopen}. If the |
| 63 | operating system supports it, ensure that the stream is setup to avoid |
| 64 | any multi-threaded locking. Otherwise return the @code{FILE} pointer |
| 65 | unchanged. |
| 66 | |
| 67 | @end deftypefn |
| 68 | |
| 69 | */ |
| 70 | |
| 71 | #ifdef HAVE_CONFIG_H |
| 72 | #include "config.h" |
| 73 | #endif |
| 74 | #include <stdio.h> |
| 75 | #ifdef HAVE_STDIO_EXT_H |
| 76 | #include <stdio_ext.h> |
| 77 | #endif |
| 78 | |
| 79 | #include "libiberty.h" |
| 80 | |
| 81 | /* This is an inline helper function to consolidate attempts to unlock |
| 82 | a stream. */ |
| 83 | |
| 84 | static inline void |
| 85 | unlock_1 (FILE *const fp ATTRIBUTE_UNUSED) |
| 86 | { |
| 87 | #if defined(HAVE___FSETLOCKING) && defined(FSETLOCKING_BYCALLER) |
| 88 | if (fp) |
| 89 | __fsetlocking (fp, FSETLOCKING_BYCALLER); |
| 90 | #endif |
| 91 | } |
| 92 | |
| 93 | void |
| 94 | unlock_stream (FILE *fp) |
| 95 | { |
| 96 | unlock_1 (fp); |
| 97 | } |
| 98 | |
| 99 | void |
| 100 | unlock_std_streams (void) |
| 101 | { |
| 102 | unlock_1 (stdin); |
| 103 | unlock_1 (stdout); |
| 104 | unlock_1 (stderr); |
| 105 | } |
| 106 | |
| 107 | FILE * |
| 108 | fopen_unlocked (const char *path, const char *mode) |
| 109 | { |
| 110 | FILE *const fp = fopen (path, mode); |
| 111 | unlock_1 (fp); |
| 112 | return fp; |
| 113 | } |
| 114 | |
| 115 | FILE * |
| 116 | fdopen_unlocked (int fildes, const char *mode) |
| 117 | { |
| 118 | FILE *const fp = fdopen (fildes, mode); |
| 119 | unlock_1 (fp); |
| 120 | return fp; |
| 121 | } |
| 122 | |
| 123 | FILE * |
| 124 | freopen_unlocked (const char *path, const char *mode, FILE *stream) |
| 125 | { |
| 126 | FILE *const fp = freopen (path, mode, stream); |
| 127 | unlock_1 (fp); |
| 128 | return fp; |
| 129 | } |