/* pthread_once.  Generic version.

   Copyright (C) 2002-2018 Free Software Foundation, Inc.

   This file is part of the GNU C Library.

   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 <pthread.h>

#include <atomic.h>

#include <pt-internal.h>

int

__pthread_once (pthread_once_t *once_control, void (*init_routine) (void))

{

  atomic_full_barrier ();

  if (once_control->__run == 0)

    {

      __pthread_spin_lock (&once_control->__lock);

      if (once_control->__run == 0)

	{

	  init_routine ();

	  atomic_full_barrier ();

	  once_control->__run = 1;

	}

      __pthread_spin_unlock (&once_control->__lock);

    }

  return 0;

}

strong_alias (__pthread_once, pthread_once);