1 /*- 2 * Copyright (c) 2003 David Xu <davidxu@freebsd.org> 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 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 * 26 * $FreeBSD$ 27 */ 28 29 #include "namespace.h" 30 #include <errno.h> 31 #include <stdlib.h> 32 #include <pthread.h> 33 #include "un-namespace.h" 34 35 #include "thr_private.h" 36 37 #define SPIN_COUNT 100000 38 39 __weak_reference(_pthread_spin_init, pthread_spin_init); 40 __weak_reference(_pthread_spin_destroy, pthread_spin_destroy); 41 __weak_reference(_pthread_spin_trylock, pthread_spin_trylock); 42 __weak_reference(_pthread_spin_lock, pthread_spin_lock); 43 __weak_reference(_pthread_spin_unlock, pthread_spin_unlock); 44 45 int 46 _pthread_spin_init(pthread_spinlock_t *lock, int pshared) 47 { 48 struct pthread_spinlock *lck; 49 int ret; 50 51 if (lock == NULL || pshared != PTHREAD_PROCESS_PRIVATE) 52 ret = EINVAL; 53 else if ((lck = malloc(sizeof(struct pthread_spinlock))) == NULL) 54 ret = ENOMEM; 55 else { 56 _thr_umutex_init(&lck->s_lock); 57 *lock = lck; 58 ret = 0; 59 } 60 61 return (ret); 62 } 63 64 int 65 _pthread_spin_destroy(pthread_spinlock_t *lock) 66 { 67 int ret; 68 69 if (lock == NULL || *lock == NULL) 70 ret = EINVAL; 71 else { 72 free(*lock); 73 *lock = NULL; 74 ret = 0; 75 } 76 77 return (ret); 78 } 79 80 int 81 _pthread_spin_trylock(pthread_spinlock_t *lock) 82 { 83 struct pthread *curthread = _get_curthread(); 84 struct pthread_spinlock *lck; 85 int ret; 86 87 if (lock == NULL || (lck = *lock) == NULL) 88 ret = EINVAL; 89 else 90 ret = THR_UMUTEX_TRYLOCK(curthread, &lck->s_lock); 91 return (ret); 92 } 93 94 int 95 _pthread_spin_lock(pthread_spinlock_t *lock) 96 { 97 struct pthread *curthread = _get_curthread(); 98 struct pthread_spinlock *lck; 99 int ret, count; 100 101 if (lock == NULL || (lck = *lock) == NULL) 102 ret = EINVAL; 103 else { 104 count = SPIN_COUNT; 105 while ((ret = THR_UMUTEX_TRYLOCK(curthread, &lck->s_lock)) != 0) { 106 while (lck->s_lock.m_owner) { 107 if (!_thr_is_smp) { 108 _pthread_yield(); 109 } else { 110 CPU_SPINWAIT; 111 112 if (--count <= 0) { 113 count = SPIN_COUNT; 114 _pthread_yield(); 115 } 116 } 117 } 118 } 119 ret = 0; 120 } 121 122 return (ret); 123 } 124 125 int 126 _pthread_spin_unlock(pthread_spinlock_t *lock) 127 { 128 struct pthread *curthread = _get_curthread(); 129 struct pthread_spinlock *lck; 130 int ret; 131 132 if (lock == NULL || (lck = *lock) == NULL) 133 ret = EINVAL; 134 else { 135 ret = THR_UMUTEX_UNLOCK(curthread, &lck->s_lock); 136 } 137 return (ret); 138 } 139