nptl/pthread_setschedparam.c

   1 /* Copyright (C) 2002, 2003, 2004, 2006, 2007 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3    Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, write to the Free
  17    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  18    02111-1307 USA.  */
  19
  20 #include <errno.h>
  21 #include <sched.h>
  22 #include <string.h>
  23 #include "pthreadP.h"
  24 #include <lowlevellock.h>
  25
  26
  27 int
  28 __pthread_setschedparam (threadid, policy, param)
  29      pthread_t threadid;
  30      int policy;
  31      const struct sched_param *param;
  32 {
  33   struct pthread *pd = (struct pthread *) threadid;
  34
  35   /* Make sure the descriptor is valid.  */
  36   if (INVALID_TD_P (pd))
  37     /* Not a valid thread handle.  */
  38     return ESRCH;
  39
  40   int result = 0;
  41
  42   lll_lock (pd->lock, LLL_PRIVATE);
  43
  44   struct sched_param p;
  45   const struct sched_param *orig_param = param;
  46
  47   /* If the thread should have higher priority because of some
  48      PTHREAD_PRIO_PROTECT mutexes it holds, adjust the priority.  */
  49   if (__builtin_expect (pd->tpp != NULL, 0)
  50       && pd->tpp->priomax > param->sched_priority)
  51     {
  52       p = *param;
  53       p.sched_priority = pd->tpp->priomax;
  54       param = &p;
  55     }
  56
  57   /* Try to set the scheduler information.  */
  58   if (__builtin_expect (__sched_setscheduler (pd->tid, policy,
  59                                               param) == -1, 0))
  60     result = errno;
  61   else
  62     {
  63       /* We succeeded changing the kernel information.  Reflect this
  64          change in the thread descriptor.  */
  65       pd->schedpolicy = policy;
  66       memcpy (&pd->schedparam, orig_param, sizeof (struct sched_param));
  67       pd->flags |= ATTR_FLAG_SCHED_SET | ATTR_FLAG_POLICY_SET;
  68     }
  69
  70   lll_unlock (pd->lock, LLL_PRIVATE);
  71
  72   return result;
  73 }
  74 strong_alias (__pthread_setschedparam, pthread_setschedparam)