nptl/pthread_setschedparam.c

   1 /* Copyright (C) 2002, 2003, 2004, 2006 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   /* We have to handle cancellation in the following code since we are
  43      locking another threads desriptor.  */
  44   pthread_cleanup_push ((void (*) (void *)) lll_unlock_wake_cb, &pd->lock);
  45
  46   lll_lock (pd->lock);
  47
  48   struct sched_param p;
  49   const struct sched_param *orig_param = param;
  50
  51   /* If the thread should have higher priority because of some
  52      PTHREAD_PRIO_PROTECT mutexes it holds, adjust the priority.  */
  53   if (__builtin_expect (pd->tpp != NULL, 0)
  54       && pd->tpp->priomax > param->sched_priority)
  55     {
  56       p = *param;
  57       p.sched_priority = pd->tpp->priomax;
  58       param = &p;
  59     }
  60
  61   /* Try to set the scheduler information.  */
  62   if (__builtin_expect (__sched_setscheduler (pd->tid, policy,
  63                                               param) == -1, 0))
  64     result = errno;
  65   else
  66     {
  67       /* We succeeded changing the kernel information.  Reflect this
  68          change in the thread descriptor.  */
  69       pd->schedpolicy = policy;
  70       memcpy (&pd->schedparam, orig_param, sizeof (struct sched_param));
  71       pd->flags |= ATTR_FLAG_SCHED_SET | ATTR_FLAG_POLICY_SET;
  72     }
  73
  74   lll_unlock (pd->lock);
  75
  76   pthread_cleanup_pop (0);
  77
  78   return result;
  79 }
  80 strong_alias (__pthread_setschedparam, pthread_setschedparam)