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/*
* 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 <errno.h>
#include <sys/param.h>
#include <pthread.h>
#include <stdlib.h>
#include "thr_private.h"
__weak_reference(_pthread_getschedparam, pthread_getschedparam);
__weak_reference(_pthread_setschedparam, pthread_setschedparam);
int
_pthread_getschedparam(pthread_t pthread, int *policy,
struct sched_param *param)
{
if (param == NULL || policy == NULL)
return (EINVAL);
if (_find_thread(pthread) == ESRCH)
return (ESRCH);
param->sched_priority = pthread->base_priority;
*policy = pthread->attr.sched_policy;
return(0);
}
int
_pthread_setschedparam(pthread_t pthread, int policy,
const struct sched_param *param)
{
struct pthread_mutex *mtx;
int old_prio;
mtx = NULL;
old_prio = 0;
if ((param == NULL) || (policy < SCHED_FIFO) || (policy > SCHED_RR))
return (EINVAL);
if ((param->sched_priority < PTHREAD_MIN_PRIORITY) ||
(param->sched_priority > PTHREAD_MAX_PRIORITY))
return (ENOTSUP);
if (_find_thread(pthread) != 0)
return (ESRCH);
/*
* If the pthread is waiting on a mutex grab it now. Doing it now
* even though we do not need it immediately greatly simplifies the
* LOR avoidance code.
*/
do {
_thread_critical_enter(pthread);
if (pthread->state == PS_MUTEX_WAIT) {
mtx = pthread->data.mutex;
if (_spintrylock(&mtx->lock) == EBUSY)
_thread_critical_exit(pthread);
else
break;
} else {
break;
}
} while (1);
PTHREAD_ASSERT(pthread->active_priority >= pthread->inherited_priority,
"active priority cannot be less than inherited priority");
old_prio = pthread->base_priority;
pthread->base_priority = param->sched_priority;
if (param->sched_priority <= pthread->active_priority) {
/*
* Active priority is affected only if it was the
* base priority and the new base priority is lower.
*/
if (pthread->active_priority == old_prio &&
pthread->active_priority != pthread->inherited_priority) {
pthread->active_priority = param->sched_priority;
readjust_priorities(pthread, mtx);
}
} else {
/*
* New base priority is greater than active priority. This
* only affects threads that are holding priority inheritance
* mutexes this thread is waiting on and its position in the
* queue.
*/
pthread->active_priority = param->sched_priority;
readjust_priorities(pthread, mtx);
}
pthread->attr.sched_policy = policy;
_thread_critical_exit(pthread);
if (mtx != NULL)
_SPINUNLOCK(&mtx->lock);
return(0);
}
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