nptl/pthread_mutexattr_setprioceiling.c

   1 /* Change priority ceiling setting in pthread_mutexattr_t.
   2    Copyright (C) 2006 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4    Contributed by Jakub Jelinek <jakub@redhat.com>, 2006.
   5
   6    The GNU C Library is free software; you can redistribute it and/or
   7    modify it under the terms of the GNU Lesser General Public
   8    License as published by the Free Software Foundation; either
   9    version 2.1 of the License, or (at your option) any later version.
  10
  11    The GNU C Library is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14    Lesser General Public License for more details.
  15
  16    You should have received a copy of the GNU Lesser General Public
  17    License along with the GNU C Library; if not, see
  18    <http://www.gnu.org/licenses/>.  */
  19
  20 #include <errno.h>
  21 #include <pthreadP.h>
  22
  23
  24 int
  25 pthread_mutexattr_setprioceiling (attr, prioceiling)
  26      pthread_mutexattr_t *attr;
  27      int prioceiling;
  28 {
  29   if (__sched_fifo_min_prio == -1)
  30     __init_sched_fifo_prio ();
  31
  32   if (__builtin_expect (prioceiling < __sched_fifo_min_prio, 0)
  33       || __builtin_expect (prioceiling > __sched_fifo_max_prio, 0)
  34       || __builtin_expect ((prioceiling
  35                             & (PTHREAD_MUTEXATTR_PRIO_CEILING_MASK
  36                                >> PTHREAD_MUTEXATTR_PRIO_CEILING_SHIFT))
  37                            != prioceiling, 0))
  38     return EINVAL;
  39
  40   struct pthread_mutexattr *iattr = (struct pthread_mutexattr *) attr;
  41
  42   iattr->mutexkind = ((iattr->mutexkind & ~PTHREAD_MUTEXATTR_PRIO_CEILING_MASK)
  43                       | (prioceiling << PTHREAD_MUTEXATTR_PRIO_CEILING_SHIFT));
  44
  45   return 0;
  46 }