1 files changed, 128 insertions, 0 deletions
diff --git a/linuxthreads/barrier.c b/linuxthreads/barrier.c
new file mode 100644
index 0000000000..37d997cfc1
--- /dev/null
+++ b/linuxthreads/barrier.c
@@ -0,0 +1,128 @@
+/* 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;
+}