1 /* $NetBSD: flockfile.c,v 1.3 2003/01/21 23:26:03 nathanw Exp $ */ 2 3 /*- 4 * Copyright (c) 2002 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Nathan J. Williams. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the NetBSD 21 * Foundation, Inc. and its contributors. 22 * 4. Neither the name of The NetBSD Foundation nor the names of its 23 * contributors may be used to endorse or promote products derived 24 * from this software without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 27 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 28 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 29 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 30 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 31 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 32 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 33 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 34 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 35 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 36 * POSSIBILITY OF SUCH DAMAGE. 37 */ 38 39 #include <sys/cdefs.h> 40 #if defined(LIBC_SCCS) && !defined(lint) 41 __RCSID("$NetBSD: flockfile.c,v 1.3 2003/01/21 23:26:03 nathanw Exp $"); 42 #endif /* LIBC_SCCS and not lint */ 43 44 #include "namespace.h" 45 46 #include <assert.h> 47 #include <errno.h> 48 #include <stdio.h> 49 #include <string.h> 50 #include "reentrant.h" 51 #include "local.h" 52 53 #ifdef __weak_alias 54 __weak_alias(flockfile,_flockfile) 55 __weak_alias(ftrylockfile,_ftrylockfile) 56 __weak_alias(funlockfile,_funlockfile) 57 #endif 58 59 #ifdef _REENTRANT 60 /* 61 * XXX This code makes the assumption that a thr_t (pthread_t) is a 62 * XXX pointer. 63 */ 64 void 65 __smutex_init(mutex_t *m) 66 { 67 mutexattr_t attr; 68 69 mutexattr_init(&attr); 70 mutexattr_settype(&attr, MUTEX_TYPE_RECURSIVE); 71 72 mutex_init(m, &attr); 73 74 mutexattr_destroy(&attr); 75 } 76 77 extern int __isthreaded; 78 79 void 80 flockfile(FILE *fp) 81 { 82 83 if (__isthreaded == 0) 84 return; 85 86 mutex_lock(&_LOCK(fp)); 87 } 88 89 int 90 ftrylockfile(FILE *fp) 91 { 92 93 if (__isthreaded == 0) 94 return 0; 95 96 return mutex_trylock(&_LOCK(fp)); 97 } 98 99 void 100 funlockfile(FILE *fp) 101 { 102 103 if (__isthreaded == 0) 104 return; 105 106 mutex_unlock(&_LOCK(fp)); 107 } 108 109 #else /* _REENTRANT */ 110 111 void 112 flockfile(FILE *fp) 113 { 114 /* LINTED deliberate lack of effect */ 115 (void)fp; 116 117 return; 118 } 119 120 int 121 ftrylockfile(FILE *fp) 122 { 123 /* LINTED deliberate lack of effect */ 124 (void)fp; 125 126 return (0); 127 } 128 129 void 130 funlockfile(FILE *fp) 131 { 132 /* LINTED deliberate lack of effect */ 133 (void)fp; 134 135 return; 136 } 137 138 #endif /* _REENTRANT */ 139