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 pthread_spinlock_t lck; 44 45 if (lock == NULL || pshared != PTHREAD_PROCESS_PRIVATE) 46 return (EINVAL); 47 lck = __malloc(sizeof(struct __pthread_spinlock_s)); 48 if (lck == NULL) 49 return (ENOMEM); 50 _thr_umtx_init(&lck->s_lock); 51 *lock = lck; 52 53 return (0); 54 } 55 56 int 57 _pthread_spin_destroy(pthread_spinlock_t *lock) 58 { 59 int ret; 60 61 if (lock == NULL || *lock == NULL) { 62 ret = EINVAL; 63 } else { 64 __free(*lock); 65 *lock = NULL; 66 ret = 0; 67 } 68 69 return (ret); 70 } 71 72 int 73 _pthread_spin_trylock(pthread_spinlock_t *lock) 74 { 75 pthread_t curthread = tls_get_curthread(); 76 pthread_spinlock_t lck; 77 78 if (lock == NULL || (lck = *lock) == NULL) 79 return (EINVAL); 80 return (THR_UMTX_TRYLOCK_PERSIST(curthread, &lck->s_lock)); 81 } 82 83 int 84 _pthread_spin_lock(pthread_spinlock_t *lock) 85 { 86 pthread_t curthread; 87 pthread_spinlock_t lck; 88 int count; 89 90 if (lock == NULL || (lck = *lock) == NULL) 91 return (EINVAL); 92 93 curthread = tls_get_curthread(); 94 count = SPIN_COUNT; 95 while (THR_UMTX_TRYLOCK_PERSIST(curthread, &lck->s_lock) != 0) { 96 while (lck->s_lock) { 97 CPU_SPINWAIT; /* tell cpu we are spinning */ 98 if (--count <= 0) { 99 count = SPIN_COUNT; 100 _pthread_yield(); 101 } 102 } 103 } 104 return (0); 105 } 106 107 int 108 _pthread_spin_unlock(pthread_spinlock_t *lock) 109 { 110 pthread_t curthread = tls_get_curthread(); 111 pthread_spinlock_t lck; 112 113 if (lock == NULL || (lck = *lock) == NULL) 114 return (EINVAL); 115 /* XXX: shouldn't return status? */ 116 THR_UMTX_UNLOCK_PERSIST(curthread, &lck->s_lock); 117 return (0); 118 } 119 120 __strong_reference(_pthread_spin_init, pthread_spin_init); 121 __strong_reference(_pthread_spin_destroy, pthread_spin_destroy); 122 __strong_reference(_pthread_spin_trylock, pthread_spin_trylock); 123 __strong_reference(_pthread_spin_lock, pthread_spin_lock); 124 __strong_reference(_pthread_spin_unlock, pthread_spin_unlock); 125