diff options
Diffstat (limited to 'cddl/contrib/opensolaris/tools/ctf/cvt/barrier.c')
-rw-r--r-- | cddl/contrib/opensolaris/tools/ctf/cvt/barrier.c | 92 |
1 files changed, 92 insertions, 0 deletions
diff --git a/cddl/contrib/opensolaris/tools/ctf/cvt/barrier.c b/cddl/contrib/opensolaris/tools/ctf/cvt/barrier.c new file mode 100644 index 0000000..bc278b0 --- /dev/null +++ b/cddl/contrib/opensolaris/tools/ctf/cvt/barrier.c @@ -0,0 +1,92 @@ +/* + * CDDL HEADER START + * + * The contents of this file are subject to the terms of the + * Common Development and Distribution License, Version 1.0 only + * (the "License"). You may not use this file except in compliance + * with the License. + * + * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE + * or http://www.opensolaris.org/os/licensing. + * See the License for the specific language governing permissions + * and limitations under the License. + * + * When distributing Covered Code, include this CDDL HEADER in each + * file and include the License file at usr/src/OPENSOLARIS.LICENSE. + * If applicable, add the following below this CDDL HEADER, with the + * fields enclosed by brackets "[]" replaced with your own identifying + * information: Portions Copyright [yyyy] [name of copyright owner] + * + * CDDL HEADER END + */ +/* + * Copyright 2002 Sun Microsystems, Inc. All rights reserved. + * Use is subject to license terms. + */ + +#pragma ident "%Z%%M% %I% %E% SMI" + +/* + * This file implements a barrier, a synchronization primitive designed to allow + * threads to wait for each other at given points. Barriers are initialized + * with a given number of threads, n, using barrier_init(). When a thread calls + * barrier_wait(), that thread blocks until n - 1 other threads reach the + * barrier_wait() call using the same barrier_t. When n threads have reached + * the barrier, they are all awakened and sent on their way. One of the threads + * returns from barrier_wait() with a return code of 1; the remaining threads + * get a return code of 0. + */ + +#include <pthread.h> +#if defined(sun) +#include <synch.h> +#endif +#include <stdio.h> + +#include "barrier.h" + +void +barrier_init(barrier_t *bar, int nthreads) +{ + pthread_mutex_init(&bar->bar_lock, NULL); +#if defined(sun) + sema_init(&bar->bar_sem, 0, USYNC_THREAD, NULL); +#else + sem_init(&bar->bar_sem, 0, 0); +#endif + + bar->bar_numin = 0; + bar->bar_nthr = nthreads; +} + +int +barrier_wait(barrier_t *bar) +{ + pthread_mutex_lock(&bar->bar_lock); + + if (++bar->bar_numin < bar->bar_nthr) { + pthread_mutex_unlock(&bar->bar_lock); +#if defined(sun) + sema_wait(&bar->bar_sem); +#else + sem_wait(&bar->bar_sem); +#endif + + return (0); + + } else { + int i; + + /* reset for next use */ + bar->bar_numin = 0; + for (i = 1; i < bar->bar_nthr; i++) +#if defined(sun) + sema_post(&bar->bar_sem); +#else + sem_post(&bar->bar_sem); +#endif + pthread_mutex_unlock(&bar->bar_lock); + + return (1); + } +} |