/* Get priority ceiling setting from pthread_mutexattr_t.

   Copyright (C) 2006-2018 Free Software Foundation, Inc.

   This file is part of the GNU C Library.

   Contributed by Jakub Jelinek <jakub@redhat.com>, 2006.

   The GNU C Library is free software; you can redistribute it and/or

   modify it under the terms of the GNU Lesser General Public

   License as published by the Free Software Foundation; either

   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,

   but WITHOUT ANY WARRANTY; without even the implied warranty of

   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public

   License along with the GNU C Library; if not, see

   <http://www.gnu.org/licenses/>.  */

#include <pthreadP.h>

#include <atomic.h>

int

pthread_mutexattr_getprioceiling (const pthread_mutexattr_t *attr,

				  int *prioceiling)

{

  const struct pthread_mutexattr *iattr;

  int ceiling;

  iattr = (const struct pthread_mutexattr *) attr;

  ceiling = ((iattr->mutexkind & PTHREAD_MUTEXATTR_PRIO_CEILING_MASK)

	     >> PTHREAD_MUTEXATTR_PRIO_CEILING_SHIFT);

  if (! ceiling)

    {

      /* See __init_sched_fifo_prio.  */

      if (atomic_load_relaxed (&__sched_fifo_min_prio) == -1)

	__init_sched_fifo_prio ();

      if (ceiling < atomic_load_relaxed (&__sched_fifo_min_prio))

	ceiling = atomic_load_relaxed (&__sched_fifo_min_prio);

    }

  *prioceiling = ceiling;

  return 0;

}