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/* Unlock a mutex. Generic version.
Copyright (C) 2000, 2002, 2008 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;
const struct __pthread_mutexattr *attr = mutex->__attr;
if (attr == __PTHREAD_ERRORCHECK_MUTEXATTR)
attr = &__pthread_errorcheck_mutexattr;
if (attr == __PTHREAD_RECURSIVE_MUTEXATTR)
attr = &__pthread_recursive_mutexattr;
__pthread_spin_lock (&mutex->__lock);
if (! attr || attr->__mutex_type == PTHREAD_MUTEX_NORMAL)
{
#if defined(ALWAYS_TRACK_MUTEX_OWNER)
# ifndef NDEBUG
if (_pthread_self ())
{
assert (mutex->__owner);
assert (mutex->__owner == _pthread_self ());
mutex->__owner = NULL;
}
# endif
#endif
}
else
switch (attr->__mutex_type)
{
case PTHREAD_MUTEX_ERRORCHECK:
case PTHREAD_MUTEX_RECURSIVE:
if (mutex->__owner != _pthread_self ())
{
__pthread_spin_unlock (&mutex->__lock);
return EPERM;
}
if (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);
#ifndef NDEBUG
# if !defined (ALWAYS_TRACK_MUTEX_OWNER)
if (attr && attr->__mutex_type != PTHREAD_MUTEX_NORMAL)
# endif
{
mutex->__owner = wakeup;
}
#endif
/* 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;
}
strong_alias (__pthread_mutex_unlock, _pthread_mutex_unlock);
strong_alias (__pthread_mutex_unlock, pthread_mutex_unlock);
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