1 files changed, 79 insertions, 0 deletions
diff --git a/libpthread/nptl/sysdeps/pthread/pthread_barrier_wait.c b/libpthread/nptl/sysdeps/pthread/pthread_barrier_wait.c
new file mode 100644
index 000000000..d1135391e
--- /dev/null
+++ b/libpthread/nptl/sysdeps/pthread/pthread_barrier_wait.c
@@ -0,0 +1,79 @@
+/* Copyright (C) 2003, 2004, 2007 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 (
+     pthread_barrier_t *barrier)
+{
+  struct pthread_barrier *ibarrier = (struct pthread_barrier *) barrier;
+  int result = 0;
+
+  /* Make sure we are alone.  */
+  lll_lock (ibarrier->lock, ibarrier->private ^ FUTEX_PRIVATE_FLAG);
+
+  /* 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,
+		      ibarrier->private ^ FUTEX_PRIVATE_FLAG);
+
+      /* 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, ibarrier->private ^ FUTEX_PRIVATE_FLAG);
+
+      /* Wait for the event counter of the barrier to change.  */
+      do
+	lll_futex_wait (&ibarrier->curr_event, event,
+			ibarrier->private ^ FUTEX_PRIVATE_FLAG);
+      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, ibarrier->private ^ FUTEX_PRIVATE_FLAG);
+
+  return result;
+}