nptl/pthread_mutexattr_setprotocol.c

   1 /* Change priority protocol setting in pthread_mutexattr_t.
   2    Copyright (C) 2006-2020 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    <https://www.gnu.org/licenses/>.  */
  19
  20 #include <errno.h>
  21 #include <pthreadP.h>
  22
  23
  24 int
  25 pthread_mutexattr_setprotocol (pthread_mutexattr_t *attr, int protocol)
  26 {
  27   if (protocol != PTHREAD_PRIO_NONE
  28       && protocol != PTHREAD_PRIO_INHERIT
  29       && __builtin_expect (protocol != PTHREAD_PRIO_PROTECT, 0))
  30     return EINVAL;
  31
  32   struct pthread_mutexattr *iattr = (struct pthread_mutexattr *) attr;
  33
  34   iattr->mutexkind = ((iattr->mutexkind & ~PTHREAD_MUTEXATTR_PROTOCOL_MASK)
  35                       | (protocol << PTHREAD_MUTEXATTR_PROTOCOL_SHIFT));
  36
  37   return 0;
  38 }