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 */ 27 28 #include "namespace.h" 29 #include <machine/tls.h> 30 #include <errno.h> 31 #include <stdlib.h> 32 #include <pthread.h> 33 #include <pthread_np.h> 34 #include "un-namespace.h" 35 36 #include "thr_private.h" 37 38 #define SPIN_COUNT 100000 39 40 int 41 _pthread_spin_init(pthread_spinlock_t *lock, int pshared) 42 { 43 struct pthread_spinlock *lck; 44 45 if (lock == NULL || pshared != PTHREAD_PROCESS_PRIVATE) 46 return (EINVAL); 47 if ((lck = malloc(sizeof(struct pthread_spinlock))) == NULL) 48 return (ENOMEM); 49 _thr_umtx_init(&lck->s_lock); 50 *lock = lck; 51 return (0); 52 } 53 54 int 55 _pthread_spin_destroy(pthread_spinlock_t *lock) 56 { 57 int ret; 58 59 if (lock == NULL || *lock == NULL) { 60 ret = EINVAL; 61 } else { 62 free(*lock); 63 *lock = NULL; 64 ret = 0; 65 } 66 return (ret); 67 } 68 69 int 70 _pthread_spin_trylock(pthread_spinlock_t *lock) 71 { 72 struct pthread *curthread = tls_get_curthread(); 73 struct pthread_spinlock *lck; 74 75 if (lock == NULL || (lck = *lock) == NULL) 76 return (EINVAL); 77 return (THR_UMTX_TRYLOCK(curthread, &lck->s_lock)); 78 } 79 80 int 81 _pthread_spin_lock(pthread_spinlock_t *lock) 82 { 83 struct pthread *curthread; 84 struct pthread_spinlock *lck; 85 int count; 86 87 if (lock == NULL || (lck = *lock) == NULL) 88 return (EINVAL); 89 90 curthread = tls_get_curthread(); 91 count = SPIN_COUNT; 92 while (THR_UMTX_TRYLOCK(curthread, &lck->s_lock) != 0) { 93 while (lck->s_lock) { 94 CPU_SPINWAIT; /* tell cpu we are spinning */ 95 if (--count <= 0) { 96 count = SPIN_COUNT; 97 _pthread_yield(); 98 } 99 } 100 } 101 return (0); 102 } 103 104 int 105 _pthread_spin_unlock(pthread_spinlock_t *lock) 106 { 107 struct pthread *curthread = tls_get_curthread(); 108 struct pthread_spinlock *lck; 109 110 if (lock == NULL || (lck = *lock) == NULL) 111 return (EINVAL); 112 /* XXX: shouldn't return status? */ 113 THR_UMTX_UNLOCK(curthread, &lck->s_lock); 114 return (0); 115 } 116 117 __strong_reference(_pthread_spin_init, pthread_spin_init); 118 __strong_reference(_pthread_spin_destroy, pthread_spin_destroy); 119 __strong_reference(_pthread_spin_trylock, pthread_spin_trylock); 120 __strong_reference(_pthread_spin_lock, pthread_spin_lock); 121 __strong_reference(_pthread_spin_unlock, pthread_spin_unlock); 122