From a6dffc4afcfb78fbb043971ecffdf5a2cfa60989 Mon Sep 17 00:00:00 2001
From: "Neal H. Walfield" <neal@gnu.org>
Date: Thu, 12 May 2005 11:50:42 +0000
Subject: libpthread/

2005-05-12  Neal H. Walfield  <neal@gnu.org>

	* Makefile (SRCS): Add sem-close.c sem-destroy.c sem-getvalue.c
	sem-init.c sem-open.c sem-post.c sem-timedwait.c sem-trywait.c
	sem-unlink.c and sem-wait.c.
	(sysdeps_headers): Add semaphore.h bits/semaphore.h.
	* include/semaphore.h: New file.
	* sysdeps/generic/sem-close.c: New file.
	* sysdeps/generic/sem-destroy.c: New file.
	* sysdeps/generic/sem-getvalue.c: New file.
	* sysdeps/generic/sem-init.c: New file.
	* sysdeps/generic/sem-open.c: New file.
	* sysdeps/generic/sem-post.c: New file.
	* sysdeps/generic/sem-timedwait.c: New file.
	* sysdeps/generic/sem-trywait.c: New file.
	* sysdeps/generic/sem-unlink.c: New file.
	* sysdeps/generic/sem-wait.c: New file.
	* sysdeps/generic/bits/semaphore.h: New file.
---
 sysdeps/generic/sem-timedwait.c | 92 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 92 insertions(+)
 create mode 100644 sysdeps/generic/sem-timedwait.c

(limited to 'sysdeps/generic/sem-timedwait.c')

diff --git a/sysdeps/generic/sem-timedwait.c b/sysdeps/generic/sem-timedwait.c
new file mode 100644
index 0000000..f3d280b
--- /dev/null
+++ b/sysdeps/generic/sem-timedwait.c
@@ -0,0 +1,92 @@
+/* Wait on a semaphore with a timeout.  Generic version.
+   Copyright (C) 2005 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Library General Public License as
+   published by the Free Software Foundation; either version 2 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
+   Library General Public License for more details.
+
+   You should have received a copy of the GNU Library 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 <semaphore.h>
+#include <error.h>
+#include <errno.h>
+#include <assert.h>
+
+#include <pt-internal.h>
+
+int
+__sem_timedwait_internal (sem_t *restrict sem,
+			  const struct timespec *restrict timeout)
+{
+  struct __pthread *self;
+
+  __pthread_spin_lock (&sem->__lock);
+  if (sem->__value > 0)
+    /* Successful down.  */
+    {
+      sem->__value --;
+      __pthread_spin_unlock (&sem->__lock);
+      return 0;
+    }
+
+  /* Add ourselves to the queue.  */
+  self = _pthread_self ();
+
+  __pthread_enqueue (&sem->__queue, self);
+  __pthread_spin_unlock (&sem->__lock);
+
+  /* Block the thread.  */
+  if (timeout)
+    {
+      error_t err;
+
+      if (timeout->tv_nsec < 0 || timeout->tv_nsec >= 1000000000)
+	{
+	  errno = EINVAL;
+	  return -1;
+	}
+
+      err = __pthread_timedblock (self, timeout);
+      if (err)
+	/* We timed out.  We may need to disconnect ourself from the
+	   waiter queue.
+
+	   FIXME: What do we do if we get a wakeup message before we
+	   disconnect ourself?  It may remain until the next time we
+	   block.  */
+	{
+	  assert (err == ETIMEDOUT);
+
+	  __pthread_spin_lock (&sem->__lock);
+	  if (self->prevp)
+	    __pthread_dequeue (self);
+	  __pthread_spin_unlock (&sem->__lock);
+
+	  errno = err;
+	  return -1;
+	}
+    }
+  else
+    __pthread_block (self);
+
+  return 0;
+}
+
+int
+__sem_timedwait (sem_t *restrict sem,
+		 const struct timespec *restrict timeout)
+{
+  return __sem_timedwait_internal (sem, timeout);
+}
+
+weak_alias (__sem_timedwait, sem_timedwait);
-- 
cgit v1.2.3