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 __weak_reference(_pthread_barrier_init, pthread_barrier_init); 38 __weak_reference(_pthread_barrier_wait, pthread_barrier_wait); 39 __weak_reference(_pthread_barrier_destroy, pthread_barrier_destroy); 40 41 int 42 _pthread_barrier_destroy(pthread_barrier_t *barrier) 43 { 44 pthread_barrier_t bar; 45 struct pthread *curthread; 46 int pshared; 47 48 if (barrier == NULL || *barrier == NULL) 49 return (EINVAL); 50 51 if (*barrier == THR_PSHARED_PTR) { 52 bar = __thr_pshared_offpage(barrier, 0); 53 if (bar == NULL) { 54 *barrier = NULL; 55 return (0); 56 } 57 pshared = 1; 58 } else { 59 bar = *barrier; 60 pshared = 0; 61 } 62 curthread = _get_curthread(); 63 THR_UMUTEX_LOCK(curthread, &bar->b_lock); 64 if (bar->b_destroying) { 65 THR_UMUTEX_UNLOCK(curthread, &bar->b_lock); 66 return (EBUSY); 67 } 68 bar->b_destroying = 1; 69 do { 70 if (bar->b_waiters > 0) { 71 bar->b_destroying = 0; 72 THR_UMUTEX_UNLOCK(curthread, &bar->b_lock); 73 return (EBUSY); 74 } 75 if (bar->b_refcount != 0) { 76 _thr_ucond_wait(&bar->b_cv, &bar->b_lock, NULL, 0); 77 THR_UMUTEX_LOCK(curthread, &bar->b_lock); 78 } else 79 break; 80 } while (1); 81 bar->b_destroying = 0; 82 THR_UMUTEX_UNLOCK(curthread, &bar->b_lock); 83 84 *barrier = NULL; 85 if (pshared) 86 __thr_pshared_destroy(barrier); 87 else 88 free(bar); 89 return (0); 90 } 91 92 int 93 _pthread_barrier_init(pthread_barrier_t *barrier, 94 const pthread_barrierattr_t *attr, unsigned count) 95 { 96 pthread_barrier_t bar; 97 int pshared; 98 99 if (barrier == NULL || count <= 0) 100 return (EINVAL); 101 102 if (attr == NULL || *attr == NULL || 103 (*attr)->pshared == PTHREAD_PROCESS_PRIVATE) { 104 bar = calloc(1, sizeof(struct pthread_barrier)); 105 if (bar == NULL) 106 return (ENOMEM); 107 *barrier = bar; 108 pshared = 0; 109 } else { 110 bar = __thr_pshared_offpage(barrier, 1); 111 if (bar == NULL) 112 return (EFAULT); 113 *barrier = THR_PSHARED_PTR; 114 pshared = 1; 115 } 116 117 _thr_umutex_init(&bar->b_lock); 118 _thr_ucond_init(&bar->b_cv); 119 if (pshared) { 120 bar->b_lock.m_flags |= USYNC_PROCESS_SHARED; 121 bar->b_cv.c_flags |= USYNC_PROCESS_SHARED; 122 } 123 bar->b_count = count; 124 return (0); 125 } 126 127 int 128 _pthread_barrier_wait(pthread_barrier_t *barrier) 129 { 130 struct pthread *curthread; 131 pthread_barrier_t bar; 132 int64_t cycle; 133 int ret; 134 135 if (barrier == NULL || *barrier == NULL) 136 return (EINVAL); 137 138 if (*barrier == THR_PSHARED_PTR) { 139 bar = __thr_pshared_offpage(barrier, 0); 140 if (bar == NULL) 141 return (EINVAL); 142 } else { 143 bar = *barrier; 144 } 145 curthread = _get_curthread(); 146 THR_UMUTEX_LOCK(curthread, &bar->b_lock); 147 if (++bar->b_waiters == bar->b_count) { 148 /* Current thread is lastest thread */ 149 bar->b_waiters = 0; 150 bar->b_cycle++; 151 _thr_ucond_broadcast(&bar->b_cv); 152 THR_UMUTEX_UNLOCK(curthread, &bar->b_lock); 153 ret = PTHREAD_BARRIER_SERIAL_THREAD; 154 } else { 155 cycle = bar->b_cycle; 156 bar->b_refcount++; 157 do { 158 _thr_ucond_wait(&bar->b_cv, &bar->b_lock, NULL, 0); 159 THR_UMUTEX_LOCK(curthread, &bar->b_lock); 160 /* test cycle to avoid bogus wakeup */ 161 } while (cycle == bar->b_cycle); 162 if (--bar->b_refcount == 0 && bar->b_destroying) 163 _thr_ucond_broadcast(&bar->b_cv); 164 THR_UMUTEX_UNLOCK(curthread, &bar->b_lock); 165 ret = 0; 166 } 167 return (ret); 168 } 169