Back to index

glibc  2.9
pthread_setschedprio.c
Go to the documentation of this file.
00001 /* Copyright (C) 2002, 2003, 2004, 2007 Free Software Foundation, Inc.
00002    This file is part of the GNU C Library.
00003    Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.
00004 
00005    The GNU C Library is free software; you can redistribute it and/or
00006    modify it under the terms of the GNU Lesser General Public
00007    License as published by the Free Software Foundation; either
00008    version 2.1 of the License, or (at your option) any later version.
00009 
00010    The GNU C Library is distributed in the hope that it will be useful,
00011    but WITHOUT ANY WARRANTY; without even the implied warranty of
00012    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00013    Lesser General Public License for more details.
00014 
00015    You should have received a copy of the GNU Lesser General Public
00016    License along with the GNU C Library; if not, write to the Free
00017    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
00018    02111-1307 USA.  */
00019 
00020 #include <errno.h>
00021 #include <sched.h>
00022 #include <string.h>
00023 #include <sched.h>
00024 #include "pthreadP.h"
00025 #include <lowlevellock.h>
00026 
00027 
00028 int
00029 pthread_setschedprio (threadid, prio)
00030      pthread_t threadid;
00031      int prio;
00032 {
00033   struct pthread *pd = (struct pthread *) threadid;
00034 
00035   /* Make sure the descriptor is valid.  */
00036   if (INVALID_TD_P (pd))
00037     /* Not a valid thread handle.  */
00038     return ESRCH;
00039 
00040   int result = 0;
00041   struct sched_param param;
00042   param.sched_priority = prio;
00043 
00044   lll_lock (pd->lock, LLL_PRIVATE);
00045 
00046   /* If the thread should have higher priority because of some
00047      PTHREAD_PRIO_PROTECT mutexes it holds, adjust the priority.  */
00048   if (__builtin_expect (pd->tpp != NULL, 0) && pd->tpp->priomax > prio)
00049     param.sched_priority = pd->tpp->priomax;
00050 
00051   /* Try to set the scheduler information.  */
00052   if (__builtin_expect (sched_setparam (pd->tid, &param) == -1, 0))
00053     result = errno;
00054   else
00055     {
00056       /* We succeeded changing the kernel information.  Reflect this
00057         change in the thread descriptor.  */
00058       param.sched_priority = prio;
00059       memcpy (&pd->schedparam, &param, sizeof (struct sched_param));
00060       pd->flags |= ATTR_FLAG_SCHED_SET;
00061     }
00062 
00063   lll_unlock (pd->lock, LLL_PRIVATE);
00064 
00065   return result;
00066 }