/* Copyright (C) 2003-2018 Free Software Foundation, Inc.

   This file is part of the GNU C Library.

   Contributed by Ulrich Drepper <drepper@redhat.com>, 2003.

   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 <assert.h>

#include <errno.h>

#include <futex-internal.h>

#include <time.h>

#include <sysdep.h>

#include "pthreadP.h"

int

pthread_condattr_setclock (pthread_condattr_t *attr, clockid_t clock_id)

{

  /* Only a few clocks are allowed.  */

  if (clock_id != CLOCK_MONOTONIC && clock_id != CLOCK_REALTIME)

    /* If more clocks are allowed some day the storing of the clock ID

       in the pthread_cond_t structure needs to be adjusted.  */

    return EINVAL;

  /* If we do not support waiting using CLOCK_MONOTONIC, return an error.  */

  if (clock_id == CLOCK_MONOTONIC

      && !futex_supports_exact_relative_timeouts())

    return ENOTSUP;

  /* Make sure the value fits in the bits we reserved.  */

  assert (clock_id < (1 << COND_CLOCK_BITS));

  int *valuep = &((struct pthread_condattr *) attr)->value;

  *valuep = ((*valuep & ~(((1 << COND_CLOCK_BITS) - 1) << 1))

	     | (clock_id << 1));

  return 0;

}