freebsd-skq/lib/libthr/thread/thr_mutex_prioceiling.c
mtm 8330d43435 o Style
o Instead of checking both the passed in pointer and its value
  for NULL, only check the latter. Any caller that passes in
  a NULL pointer is obviously wrong.
2004-02-18 15:22:52 +00:00

114 lines
3.6 KiB
C

/*
* Copyright (c) 1998 Daniel Eischen <eischen@vigrid.com>.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by Daniel Eischen.
* 4. Neither the name of the author nor the names of any co-contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY DANIEL EISCHEN AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $FreeBSD$
*/
#include <string.h>
#include <stdlib.h>
#include <errno.h>
#include <pthread.h>
#include "thr_private.h"
__weak_reference(_pthread_mutexattr_getprioceiling, pthread_mutexattr_getprioceiling);
__weak_reference(_pthread_mutexattr_setprioceiling, pthread_mutexattr_setprioceiling);
__weak_reference(_pthread_mutex_getprioceiling, pthread_mutex_getprioceiling);
__weak_reference(_pthread_mutex_setprioceiling, pthread_mutex_setprioceiling);
int
_pthread_mutexattr_getprioceiling(pthread_mutexattr_t *mattr, int *prioceiling)
{
int ret = 0;
if (*mattr == NULL)
ret = EINVAL;
else
*prioceiling = (*mattr)->m_ceiling;
return(ret);
}
int
_pthread_mutexattr_setprioceiling(pthread_mutexattr_t *mattr, int prioceiling)
{
int ret = 0;
if (*mattr == NULL)
ret = EINVAL;
else if (prioceiling <= PTHREAD_MAX_PRIORITY &&
prioceiling >= PTHREAD_MIN_PRIORITY)
(*mattr)->m_ceiling = prioceiling;
else
ret = EINVAL;
return (ret);
}
int
_pthread_mutex_getprioceiling(pthread_mutex_t *mutex,
int *prioceiling)
{
if (*mutex == NULL)
return (EINVAL);
else
*prioceiling = (*mutex)->m_prio;
return (0);
}
int
_pthread_mutex_setprioceiling(pthread_mutex_t *mutex,
int prioceiling, int *old_ceiling)
{
int ret = 0;
if (*mutex == NULL)
return (EINVAL);
else if (prioceiling > PTHREAD_MAX_PRIORITY ||
prioceiling < PTHREAD_MIN_PRIORITY)
return (EINVAL);
/*
* Because of the use of pthread_mutex_unlock(), the
* priority ceiling of a mutex cannot be changed
* while the mutex is held by another thread. It also,
* means that the the thread trying to change the
* priority ceiling must adhere to prio protection rules.
*/
if ((ret = pthread_mutex_lock(mutex)) == 0) {
/* Return the old ceiling and set the new ceiling: */
*old_ceiling = (*mutex)->m_prio;
(*mutex)->m_prio = prioceiling;
/* Unlock the mutex: */
ret = pthread_mutex_unlock(mutex);
}
return(ret);
}