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 46 if (barrier == NULL || *barrier == NULL) 47 return (EINVAL); 48 49 bar = *barrier; 50 if (bar->b_waiters > 0) 51 return (EBUSY); 52 *barrier = NULL; 53 free(bar); 54 return (0); 55 } 56 57 int 58 _pthread_barrier_init(pthread_barrier_t *barrier, 59 const pthread_barrierattr_t *attr, unsigned count) 60 { 61 pthread_barrier_t bar; 62 63 (void)attr; 64 65 if (barrier == NULL || count <= 0) 66 return (EINVAL); 67 68 bar = malloc(sizeof(struct pthread_barrier)); 69 if (bar == NULL) 70 return (ENOMEM); 71 72 _thr_umutex_init(&bar->b_lock); 73 _thr_ucond_init(&bar->b_cv); 74 bar->b_cycle = 0; 75 bar->b_waiters = 0; 76 bar->b_count = count; 77 *barrier = bar; 78 79 return (0); 80 } 81 82 int 83 _pthread_barrier_wait(pthread_barrier_t *barrier) 84 { 85 struct pthread *curthread = _get_curthread(); 86 pthread_barrier_t bar; 87 int64_t cycle; 88 int ret; 89 90 if (barrier == NULL || *barrier == NULL) 91 return (EINVAL); 92 93 bar = *barrier; 94 THR_UMUTEX_LOCK(curthread, &bar->b_lock); 95 if (++bar->b_waiters == bar->b_count) { 96 /* Current thread is lastest thread */ 97 bar->b_waiters = 0; 98 bar->b_cycle++; 99 _thr_ucond_broadcast(&bar->b_cv); 100 THR_UMUTEX_UNLOCK(curthread, &bar->b_lock); 101 ret = PTHREAD_BARRIER_SERIAL_THREAD; 102 } else { 103 cycle = bar->b_cycle; 104 do { 105 _thr_ucond_wait(&bar->b_cv, &bar->b_lock, NULL, 0); 106 THR_UMUTEX_LOCK(curthread, &bar->b_lock); 107 /* test cycle to avoid bogus wakeup */ 108 } while (cycle == bar->b_cycle); 109 THR_UMUTEX_UNLOCK(curthread, &bar->b_lock); 110 ret = 0; 111 } 112 return (ret); 113 } 114