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-rw-r--r--linuxthreads/barrier.c128
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diff --git a/linuxthreads/barrier.c b/linuxthreads/barrier.c
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+/* POSIX barrier implementation for LinuxThreads.
+ Copyright (C) 2000, 2003 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+ Contributed by Kaz Kylheku <kaz@ashi.footprints.net>, 2000.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public License as
+ published by the Free Software Foundation; either version 2.1 of the
+ License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; see the file COPYING.LIB. If not,
+ write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ Boston, MA 02111-1307, USA. */
+
+#include <errno.h>
+#include "pthread.h"
+#include "internals.h"
+#include "spinlock.h"
+#include "queue.h"
+#include "restart.h"
+
+int
+pthread_barrier_wait(pthread_barrier_t *barrier)
+{
+ pthread_descr self = thread_self();
+ pthread_descr temp_wake_queue, th;
+ int result = 0;
+
+ __pthread_lock(&barrier->__ba_lock, self);
+
+ /* If the required number of threads have achieved rendezvous... */
+ if (barrier->__ba_present >= barrier->__ba_required - 1)
+ {
+ /* ... then this last caller shall be the serial thread */
+ result = PTHREAD_BARRIER_SERIAL_THREAD;
+ /* Copy and clear wait queue and reset barrier. */
+ temp_wake_queue = barrier->__ba_waiting;
+ barrier->__ba_waiting = NULL;
+ barrier->__ba_present = 0;
+ }
+ else
+ {
+ result = 0;
+ barrier->__ba_present++;
+ enqueue(&barrier->__ba_waiting, self);
+ }
+
+ __pthread_unlock(&barrier->__ba_lock);
+
+ if (result == 0)
+ {
+ /* Non-serial threads have to suspend */
+ suspend(self);
+ /* We don't bother dealing with cancellation because the POSIX
+ spec for barriers doesn't mention that pthread_barrier_wait
+ is a cancellation point. */
+ }
+ else
+ {
+ /* Serial thread wakes up all others. */
+ while ((th = dequeue(&temp_wake_queue)) != NULL)
+ restart(th);
+ }
+
+ return result;
+}
+
+int
+pthread_barrier_init(pthread_barrier_t *barrier,
+ const pthread_barrierattr_t *attr,
+ unsigned int count)
+{
+ if (count == 0)
+ return EINVAL;
+
+ __pthread_init_lock(&barrier->__ba_lock);
+ barrier->__ba_required = count;
+ barrier->__ba_present = 0;
+ barrier->__ba_waiting = NULL;
+ return 0;
+}
+
+int
+pthread_barrier_destroy(pthread_barrier_t *barrier)
+{
+ if (barrier->__ba_waiting != NULL) return EBUSY;
+ return 0;
+}
+
+int
+pthread_barrierattr_init(pthread_barrierattr_t *attr)
+{
+ attr->__pshared = PTHREAD_PROCESS_PRIVATE;
+ return 0;
+}
+
+int
+pthread_barrierattr_destroy(pthread_barrierattr_t *attr)
+{
+ return 0;
+}
+
+int
+__pthread_barrierattr_getpshared(const pthread_barrierattr_t *attr,
+ int *pshared)
+{
+ *pshared = PTHREAD_PROCESS_PRIVATE;
+ return 0;
+}
+
+int
+pthread_barrierattr_setpshared(pthread_barrierattr_t *attr, int pshared)
+{
+ if (pshared != PTHREAD_PROCESS_PRIVATE && pshared != PTHREAD_PROCESS_SHARED)
+ return EINVAL;
+
+ /* For now it is not possible to shared a conditional variable. */
+ if (pshared != PTHREAD_PROCESS_PRIVATE)
+ return ENOSYS;
+
+ return 0;
+}