glibc/nptl/pthread_setschedprio.c

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/* Copyright (C) 2002, 2003, 2004 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, write to the Free
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA. */
#include <errno.h>
#include <sched.h>
#include <string.h>
#include <sched.h>
#include "pthreadP.h"
#include <lowlevellock.h>
int
pthread_setschedprio (threadid, prio)
pthread_t threadid;
int prio;
{
struct pthread *pd = (struct pthread *) threadid;
/* Make sure the descriptor is valid. */
if (INVALID_TD_P (pd))
/* Not a valid thread handle. */
return ESRCH;
int result = 0;
struct sched_param param;
param.sched_priority = prio;
/* We have to handle cancellation in the following code since we are
locking another threads desriptor. */
pthread_cleanup_push ((void (*) (void *)) lll_unlock_wake_cb, &pd->lock);
lll_lock (pd->lock);
/* If the thread should have higher priority because of some
PTHREAD_PRIO_PROTECT mutexes it holds, adjust the priority. */
if (__builtin_expect (pd->tpp != NULL, 0) && pd->tpp->priomax > prio)
param.sched_priority = pd->tpp->priomax;
/* Try to set the scheduler information. */
if (__builtin_expect (sched_setparam (pd->tid, &param) == -1, 0))
result = errno;
else
{
/* We succeeded changing the kernel information. Reflect this
change in the thread descriptor. */
param.sched_priority = prio;
memcpy (&pd->schedparam, &param, sizeof (struct sched_param));
pd->flags |= ATTR_FLAG_SCHED_SET;
}
lll_unlock (pd->lock);
pthread_cleanup_pop (0);
return result;
}