1 /* $NetBSD: mtx.c,v 1.1 2019/04/24 11:43:19 kamil Exp $ */ 2 3 /*- 4 * Copyright (c) 2016 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Kamil Rytarowski. 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 * 19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 29 * POSSIBILITY OF SUCH DAMAGE. 30 */ 31 32 #include <sys/cdefs.h> 33 __RCSID("$NetBSD: mtx.c,v 1.1 2019/04/24 11:43:19 kamil Exp $"); 34 35 #include <assert.h> 36 #include <errno.h> 37 #include <pthread.h> 38 #include <threads.h> 39 40 void 41 mtx_destroy(mtx_t *mtx) 42 { 43 44 _DIAGASSERT(mtx != NULL); 45 46 /* 47 * The cnd_destroy(3) function that conforms to C11 returns no value. 48 */ 49 (void)pthread_mutex_destroy(mtx); 50 } 51 52 static inline int 53 mtx_init_default(mtx_t *mtx) 54 { 55 56 _DIAGASSERT(mtx != NULL); 57 58 if (pthread_mutex_init(mtx, NULL) != 0) 59 return thrd_error; 60 61 return thrd_success; 62 } 63 64 static inline int 65 mtx_init_recursive(mtx_t *mtx) 66 { 67 pthread_mutexattr_t attr; 68 69 _DIAGASSERT(mtx != NULL); 70 71 if (pthread_mutexattr_init(&attr) != 0) 72 return thrd_error; 73 74 if (pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_RECURSIVE) != 0) { 75 pthread_mutexattr_destroy(&attr); 76 77 return thrd_error; 78 } 79 80 if (pthread_mutex_init(mtx, &attr) == 0) 81 return thrd_success; 82 83 pthread_mutexattr_destroy(&attr); 84 85 return thrd_error; 86 } 87 88 int 89 mtx_init(mtx_t *mtx, int type) 90 { 91 92 _DIAGASSERT(mtx != NULL); 93 94 switch (type) { 95 case mtx_plain: 96 case mtx_timed: 97 return mtx_init_default(mtx); 98 case mtx_plain | mtx_recursive: 99 case mtx_timed | mtx_recursive: 100 return mtx_init_recursive(mtx); 101 default: 102 return thrd_error; 103 } 104 } 105 106 int 107 mtx_lock(mtx_t *mtx) 108 { 109 110 _DIAGASSERT(mtx != NULL); 111 112 if (pthread_mutex_lock(mtx) == 0) 113 return thrd_success; 114 115 return thrd_error; 116 } 117 118 int 119 mtx_timedlock(mtx_t *__restrict mtx, const struct timespec *__restrict ts) 120 { 121 122 _DIAGASSERT(mtx != NULL); 123 _DIAGASSERT(ts != NULL); 124 125 switch(pthread_mutex_timedlock(mtx, ts)) { 126 case 0: 127 return thrd_success; 128 case ETIMEDOUT: 129 return thrd_timedout; 130 default: 131 return thrd_error; 132 } 133 } 134 135 int 136 mtx_trylock(mtx_t *mtx) 137 { 138 139 _DIAGASSERT(mtx != NULL); 140 141 switch(pthread_mutex_trylock(mtx)) { 142 case 0: 143 return thrd_success; 144 case EBUSY: 145 return thrd_busy; 146 default: 147 return thrd_error; 148 } 149 } 150 151 int 152 mtx_unlock(mtx_t *mtx) 153 { 154 155 _DIAGASSERT(mtx != NULL); 156 157 if (pthread_mutex_unlock(mtx) == 0) 158 return thrd_success; 159 160 return thrd_error; 161 } 162