1 files changed, 111 insertions, 0 deletions
diff --git a/lib/libthr/thread/thr_barrier.c b/lib/libthr/thread/thr_barrier.c
new file mode 100644
index 0000000..8d65d9f
--- /dev/null
+++ b/lib/libthr/thread/thr_barrier.c
@@ -0,0 +1,111 @@
+/*-
+ * Copyright (c) 2003 David Xu <davidxu@freebsd.org>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * $FreeBSD$
+ */
+
+#include "namespace.h"
+#include <errno.h>
+#include <stdlib.h>
+#include <pthread.h>
+#include "un-namespace.h"
+
+#include "thr_private.h"
+
+__weak_reference(_pthread_barrier_init,		pthread_barrier_init);
+__weak_reference(_pthread_barrier_wait,		pthread_barrier_wait);
+__weak_reference(_pthread_barrier_destroy,	pthread_barrier_destroy);
+
+int
+_pthread_barrier_destroy(pthread_barrier_t *barrier)
+{
+	pthread_barrier_t	bar;
+
+	if (barrier == NULL || *barrier == NULL)
+		return (EINVAL);
+
+	bar = *barrier;
+	if (bar->b_waiters > 0)
+		return (EBUSY);
+	*barrier = NULL;
+	free(bar);
+	return (0);
+}
+
+int
+_pthread_barrier_init(pthread_barrier_t *barrier,
+		      const pthread_barrierattr_t *attr, unsigned count)
+{
+	pthread_barrier_t	bar;
+
+	(void)attr;
+
+	if (barrier == NULL || count <= 0)
+		return (EINVAL);
+
+	bar = malloc(sizeof(struct pthread_barrier));
+	if (bar == NULL)
+		return (ENOMEM);
+
+	_thr_umtx_init(&bar->b_lock);
+	bar->b_cycle	= 0;
+	bar->b_waiters	= 0;
+	bar->b_count	= count;
+	*barrier	= bar;
+
+	return (0);
+}
+
+int
+_pthread_barrier_wait(pthread_barrier_t *barrier)
+{
+	struct pthread *curthread = _get_curthread();
+	pthread_barrier_t bar;
+	long cycle;
+	int ret;
+
+	if (barrier == NULL || *barrier == NULL)
+		return (EINVAL);
+
+	bar = *barrier;
+	THR_UMTX_LOCK(curthread, &bar->b_lock);
+	if (++bar->b_waiters == bar->b_count) {
+		/* Current thread is lastest thread */
+		bar->b_waiters = 0;
+		bar->b_cycle++;
+		_thr_umtx_wake(&bar->b_cycle, bar->b_count - 1);
+		THR_UMTX_UNLOCK(curthread, &bar->b_lock);
+		ret = PTHREAD_BARRIER_SERIAL_THREAD;
+	} else {
+		cycle = bar->b_cycle;
+		THR_UMTX_UNLOCK(curthread, &bar->b_lock);
+		do {
+			_thr_umtx_wait(&bar->b_cycle, cycle, NULL);
+			/* test cycle to avoid bogus wakeup */
+		} while (cycle == bar->b_cycle);
+		ret = 0;
+	}
+	return (ret);
+}