2 * Copyright (c) 2003 David Xu <davidxu@freebsd.org>
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
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.
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
26 * $FreeBSD: src/lib/libpthread/thread/thr_barrier.c,v 1.1 2003/09/04 14:06:43 davidxu Exp $
27 * $DragonFly: src/lib/libthread_xu/thread/thr_barrier.c,v 1.4 2005/03/29 19:26:20 joerg Exp $
30 #include <machine/tls.h>
36 #include "thr_private.h"
38 __weak_reference(_pthread_barrier_init, pthread_barrier_init);
39 __weak_reference(_pthread_barrier_wait, pthread_barrier_wait);
40 __weak_reference(_pthread_barrier_destroy, pthread_barrier_destroy);
43 _pthread_barrier_destroy(pthread_barrier_t *barrier)
45 pthread_barrier_t bar;
47 if (barrier == NULL || *barrier == NULL)
51 if (bar->b_waiters > 0)
59 _pthread_barrier_init(pthread_barrier_t *barrier,
60 const pthread_barrierattr_t *attr, int count)
62 pthread_barrier_t bar;
64 if (barrier == NULL || count <= 0)
67 bar = malloc(sizeof(struct pthread_barrier));
71 _thr_umtx_init(&bar->b_lock);
81 _pthread_barrier_wait(pthread_barrier_t *barrier)
83 struct pthread *curthread = tls_get_curthread();
84 pthread_barrier_t bar;
88 if (barrier == NULL || *barrier == NULL)
92 THR_UMTX_LOCK(curthread, &bar->b_lock);
93 if (++bar->b_waiters == bar->b_count) {
94 /* Current thread is lastest thread */
97 _thr_umtx_wake(&bar->b_cycle, bar->b_count);
98 THR_UMTX_UNLOCK(curthread, &bar->b_lock);
99 ret = PTHREAD_BARRIER_SERIAL_THREAD;
101 cycle = bar->b_cycle;
102 THR_UMTX_UNLOCK(curthread, &bar->b_lock);
104 _thr_umtx_wait(&bar->b_cycle, cycle, NULL, 0);
105 /* test cycle to avoid bogus wakeup */
106 } while (cycle == bar->b_cycle);