nptl/pthread_getschedparam.c

   1 /* Copyright (C) 2002, 2003, 2004, 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, see
  17    <http://www.gnu.org/licenses/>.  */
  18
  19 #include <errno.h>
  20 #include <string.h>
  21 #include "pthreadP.h"
  22 #include <lowlevellock.h>
  23
  24
  25 int
  26 __pthread_getschedparam (threadid, policy, param)
  27      pthread_t threadid;
  28      int *policy;
  29      struct sched_param *param;
  30 {
  31   struct pthread *pd = (struct pthread *) threadid;
  32
  33   /* Make sure the descriptor is valid.  */
  34   if (INVALID_TD_P (pd))
  35     /* Not a valid thread handle.  */
  36     return ESRCH;
  37
  38   int result = 0;
  39
  40   lll_lock (pd->lock, LLL_PRIVATE);
  41
  42   /* The library is responsible for maintaining the values at all
  43      times.  If the user uses a interface other than
  44      pthread_setschedparam to modify the scheduler setting it is not
  45      the library's problem.  In case the descriptor's values have
  46      not yet been retrieved do it now.  */
  47   if ((pd->flags & ATTR_FLAG_SCHED_SET) == 0)
  48     {
  49       if (__sched_getparam (pd->tid, &pd->schedparam) != 0)
  50         result = 1;
  51       else
  52         pd->flags |= ATTR_FLAG_SCHED_SET;
  53     }
  54
  55   if ((pd->flags & ATTR_FLAG_POLICY_SET) == 0)
  56     {
  57       pd->schedpolicy = __sched_getscheduler (pd->tid);
  58       if (pd->schedpolicy == -1)
  59         result = 1;
  60       else
  61         pd->flags |= ATTR_FLAG_POLICY_SET;
  62     }
  63
  64   if (result == 0)
  65     {
  66       *policy = pd->schedpolicy;
  67       memcpy (param, &pd->schedparam, sizeof (struct sched_param));
  68     }
  69
  70   lll_unlock (pd->lock, LLL_PRIVATE);
  71
  72   return result;
  73 }
  74 strong_alias (__pthread_getschedparam, pthread_getschedparam)