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+/* Copyright (C) 2003, 2004 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+ Contributed by Martin Schwidefsky <schwidefsky@de.ibm.com>, 2003.
+
+ 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; if not, write to the Free
+ Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+ 02111-1307 USA. */
+
+#include <errno.h>
+#include <sysdep.h>
+#include <lowlevellock.h>
+#include <pthreadP.h>
+
+
+/* Wait on barrier. */
+int
+pthread_barrier_wait (barrier)
+ pthread_barrier_t *barrier;
+{
+ struct pthread_barrier *ibarrier = (struct pthread_barrier *) barrier;
+ int result = 0;
+
+ /* Make sure we are alone. */
+ lll_lock (ibarrier->lock);
+
+ /* One more arrival. */
+ --ibarrier->left;
+
+ /* Are these all? */
+ if (ibarrier->left == 0)
+ {
+ /* Yes. Increment the event counter to avoid invalid wake-ups and
+ tell the current waiters that it is their turn. */
+ ++ibarrier->curr_event;
+
+ /* Wake up everybody. */
+ lll_futex_wake (&ibarrier->curr_event, INT_MAX);
+
+ /* This is the thread which finished the serialization. */
+ result = PTHREAD_BARRIER_SERIAL_THREAD;
+ }
+ else
+ {
+ /* The number of the event we are waiting for. The barrier's event
+ number must be bumped before we continue. */
+ unsigned int event = ibarrier->curr_event;
+
+ /* Before suspending, make the barrier available to others. */
+ lll_unlock (ibarrier->lock);
+
+ /* Wait for the event counter of the barrier to change. */
+ do
+ lll_futex_wait (&ibarrier->curr_event, event);
+ while (event == ibarrier->curr_event);
+ }
+
+ /* Make sure the init_count is stored locally or in a register. */
+ unsigned int init_count = ibarrier->init_count;
+
+ /* If this was the last woken thread, unlock. */
+ if (atomic_increment_val (&ibarrier->left) == init_count)
+ /* We are done. */
+ lll_unlock (ibarrier->lock);
+
+ return result;
+}