diff libgomp/config/posix/sem.c @ 0:a06113de4d67

first commit
author kent <kent@cr.ie.u-ryukyu.ac.jp>
date Fri, 17 Jul 2009 14:47:48 +0900
parents
children 04ced10e8804
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--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/libgomp/config/posix/sem.c	Fri Jul 17 14:47:48 2009 +0900
@@ -0,0 +1,123 @@
+/* Copyright (C) 2005, 2006, 2009 Free Software Foundation, Inc.
+   Contributed by Richard Henderson <rth@redhat.com>.
+
+   This file is part of the GNU OpenMP Library (libgomp).
+
+   Libgomp is free software; you can redistribute it and/or modify it
+   under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3, or (at your option)
+   any later version.
+
+   Libgomp 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 General Public License for
+   more details.
+
+   Under Section 7 of GPL version 3, you are granted additional
+   permissions described in the GCC Runtime Library Exception, version
+   3.1, as published by the Free Software Foundation.
+
+   You should have received a copy of the GNU General Public License and
+   a copy of the GCC Runtime Library Exception along with this program;
+   see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
+   <http://www.gnu.org/licenses/>.  */
+
+/* This is the default POSIX 1003.1b implementation of a semaphore
+   synchronization mechanism for libgomp.  This type is private to
+   the library.
+
+   This is a bit heavy weight for what we need, in that we're not
+   interested in sem_wait as a cancelation point, but it's not too
+   bad for a default.  */
+
+#include "libgomp.h"
+
+#ifdef HAVE_BROKEN_POSIX_SEMAPHORES
+#include <stdlib.h>
+
+void gomp_sem_init (gomp_sem_t *sem, int value)
+{
+  int ret;
+
+  ret = pthread_mutex_init (&sem->mutex, NULL);
+  if (ret)
+    return;
+
+  ret = pthread_cond_init (&sem->cond, NULL);
+  if (ret)
+    return;
+
+  sem->value = value;
+}
+
+void gomp_sem_wait (gomp_sem_t *sem)
+{
+  int ret;
+
+  ret = pthread_mutex_lock (&sem->mutex);
+  if (ret)
+    return;
+
+  if (sem->value > 0)
+    {
+      sem->value--;
+      ret = pthread_mutex_unlock (&sem->mutex);
+      return;
+    }
+
+  while (sem->value <= 0)
+    {
+      ret = pthread_cond_wait (&sem->cond, &sem->mutex);
+      if (ret)
+	{
+	  pthread_mutex_unlock (&sem->mutex);
+	  return;
+	}
+    }
+
+  sem->value--;
+  ret = pthread_mutex_unlock (&sem->mutex);
+  return;
+}
+
+void gomp_sem_post (gomp_sem_t *sem)
+{
+  int ret;
+
+  ret = pthread_mutex_lock (&sem->mutex);
+  if (ret)
+    return;
+
+  sem->value++;
+
+  ret = pthread_mutex_unlock (&sem->mutex);
+  if (ret)
+    return;
+
+  ret = pthread_cond_signal (&sem->cond);
+
+  return;
+}
+
+void gomp_sem_destroy (gomp_sem_t *sem)
+{
+  int ret;
+
+  ret = pthread_mutex_destroy (&sem->mutex);
+  if (ret)
+    return;
+
+  ret = pthread_cond_destroy (&sem->cond);
+
+  return;
+}
+#else /* HAVE_BROKEN_POSIX_SEMAPHORES  */
+void
+gomp_sem_wait (gomp_sem_t *sem)
+{
+  /* With POSIX, the wait can be canceled by signals.  We don't want that.
+     It is expected that the return value here is -1 and errno is EINTR.  */
+  while (sem_wait (sem) != 0)
+    continue;
+}
+#endif