2004-03-17 Marcus Brinkmann <marcus@gnu.org>

	* libpthread: New directory, populated with Neal H. Walfields
	pthread implementation.

1 files changed, 82 insertions, 0 deletions

diff --git a/libpthread/sysdeps/generic/pt-mutex-unlock.c b/libpthread/sysdeps/generic/pt-mutex-unlock.c
new file mode 100644
index 0000000..bbbe2b8
--- /dev/null
+++ b/libpthread/sysdeps/generic/pt-mutex-unlock.c
@@ -0,0 +1,82 @@
+/* Unlock a mutex.  Generic version.
+   Copyright (C) 2000,02 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 <pthread.h>
+
+#include <pt-internal.h>
+
+#define LOSE do { * (int *) 0 = 0; } while (1)
+
+/* Unlock MUTEX, rescheduling a waiting thread.  */
+int
+__pthread_mutex_unlock (pthread_mutex_t *mutex)
+{
+  struct __pthread *wakeup;
+  
+  __pthread_spin_lock (&mutex->__lock);
+
+  if (mutex->attr)
+    switch (mutex->attr->mutex_type)
+      {
+      case PTHREAD_MUTEX_NORMAL:
+	break;
+
+      case PTHREAD_MUTEX_ERRORCHECK:
+      case PTHREAD_MUTEX_RECURSIVE:
+	if (mutex->owner != _pthread_self ())
+	  {
+	    __pthread_spin_unlock (&mutex->__lock);
+	    return EPERM;
+	  }
+
+	if (mutex->attr->mutex_type == PTHREAD_MUTEX_RECURSIVE)
+	  if (--mutex->locks > 0)
+	    {
+	      __pthread_spin_unlock (&mutex->__lock);
+	      return 0;
+	    }
+
+	mutex->owner = 0;
+	break;
+
+      default:
+	LOSE;
+      }
+
+  if (mutex->__queue == NULL)
+    {
+      __pthread_spin_unlock (&mutex->__held);
+      __pthread_spin_unlock (&mutex->__lock);
+      return 0;
+    }
+
+  wakeup = mutex->__queue;
+  __pthread_dequeue (wakeup);
+
+  /* We do not unlock MUTEX->held: we are transferring the ownership
+     to the thread that we are waking up.  */
+
+  __pthread_spin_unlock (&mutex->__lock);
+  __pthread_wakeup (wakeup);
+
+  return 0;
+}
+
+weak_alias (__pthread_mutex_unlock, _pthread_mutex_unlock);
+weak_alias (__pthread_mutex_unlock, pthread_mutex_unlock);