1 /* Implement fopen_unlocked and related functions. 2 Copyright (C) 2005 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}, const char * @var{mode}) 40 41 Opens and returns a @code{FILE} pointer via @code{fopen}. If the 42 operating system supports it, ensure that the stream is setup to avoid 43 any multi-threaded locking. Otherwise return the @code{FILE} pointer 44 unchanged. 45 46 @end deftypefn 47 48 @deftypefn Extension {FILE *} fdopen_unlocked (int @var{fildes}, const char * @var{mode}) 49 50 Opens and returns a @code{FILE} pointer via @code{fdopen}. If the 51 operating system supports it, ensure that the stream is setup to avoid 52 any multi-threaded locking. Otherwise return the @code{FILE} pointer 53 unchanged. 54 55 @end deftypefn 56 57 @deftypefn Extension {FILE *} freopen_unlocked (const char * @var{path}, const char * @var{mode}, FILE * @var{stream}) 58 59 Opens and returns a @code{FILE} pointer via @code{freopen}. If the 60 operating system supports it, ensure that the stream is setup to avoid 61 any multi-threaded locking. Otherwise return the @code{FILE} pointer 62 unchanged. 63 64 @end deftypefn 65 66 */ 67 68 #ifdef HAVE_CONFIG_H 69 #include "config.h" 70 #endif 71 #include <stdio.h> 72 #ifdef HAVE_STDIO_EXT_H 73 #include <stdio_ext.h> 74 #endif 75 76 #include "libiberty.h" 77 78 /* This is an inline helper function to consolidate attempts to unlock 79 a stream. */ 80 81 static inline void 82 unlock_1 (FILE *const fp ATTRIBUTE_UNUSED) 83 { 84 #if defined(HAVE___FSETLOCKING) && defined(FSETLOCKING_BYCALLER) 85 if (fp) 86 __fsetlocking (fp, FSETLOCKING_BYCALLER); 87 #endif 88 } 89 90 void 91 unlock_stream (FILE *fp) 92 { 93 unlock_1 (fp); 94 } 95 96 void 97 unlock_std_streams (void) 98 { 99 unlock_1 (stdin); 100 unlock_1 (stdout); 101 unlock_1 (stderr); 102 } 103 104 FILE * 105 fopen_unlocked (const char *path, const char *mode) 106 { 107 FILE *const fp = fopen (path, mode); 108 unlock_1 (fp); 109 return fp; 110 } 111 112 FILE * 113 fdopen_unlocked (int fildes, const char *mode) 114 { 115 FILE *const fp = fdopen (fildes, mode); 116 unlock_1 (fp); 117 return fp; 118 } 119 120 FILE * 121 freopen_unlocked (const char *path, const char *mode, FILE *stream) 122 { 123 FILE *const fp = freopen (path, mode, stream); 124 unlock_1 (fp); 125 return fp; 126 } 127