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glibc  2.9
pthread_setschedparam.c
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00001 /* Copyright (C) 2002, 2003, 2004, 2006, 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 "pthreadP.h"
00024 #include <lowlevellock.h>
00025 
00026 
00027 int
00028 __pthread_setschedparam (threadid, policy, param)
00029      pthread_t threadid;
00030      int policy;
00031      const struct sched_param *param;
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 
00042   lll_lock (pd->lock, LLL_PRIVATE);
00043 
00044   struct sched_param p;
00045   const struct sched_param *orig_param = param;
00046 
00047   /* If the thread should have higher priority because of some
00048      PTHREAD_PRIO_PROTECT mutexes it holds, adjust the priority.  */
00049   if (__builtin_expect (pd->tpp != NULL, 0)
00050       && pd->tpp->priomax > param->sched_priority)
00051     {
00052       p = *param;
00053       p.sched_priority = pd->tpp->priomax;
00054       param = &p;
00055     }
00056 
00057   /* Try to set the scheduler information.  */
00058   if (__builtin_expect (__sched_setscheduler (pd->tid, policy,
00059                                          param) == -1, 0))
00060     result = errno;
00061   else
00062     {
00063       /* We succeeded changing the kernel information.  Reflect this
00064         change in the thread descriptor.  */
00065       pd->schedpolicy = policy;
00066       memcpy (&pd->schedparam, orig_param, sizeof (struct sched_param));
00067       pd->flags |= ATTR_FLAG_SCHED_SET | ATTR_FLAG_POLICY_SET;
00068     }
00069 
00070   lll_unlock (pd->lock, LLL_PRIVATE);
00071 
00072   return result;
00073 }
00074 strong_alias (__pthread_setschedparam, pthread_setschedparam)