/* Spin locks.

   Copyright (C) 2000-2018 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 <sched.h>

/* The default for single processor machines; don't spin, it's

   pointless.  */

#ifndef __PTHREAD_SPIN_COUNT

# define __PTHREAD_SPIN_COUNT 1

#endif

/* The number of times to spin while trying to lock a spin lock object

   before yielding the processor. */

int __pthread_spin_count = __PTHREAD_SPIN_COUNT;

/* Lock the spin lock object LOCK.  If the lock is held by another

   thread spin until it becomes available.  */

int

_pthread_spin_lock (__pthread_spinlock_t *lock)

{

  int i;

  while (1)

    {

      for (i = 0; i < __pthread_spin_count; i++)

	{

	  if (__pthread_spin_trylock (lock) == 0)

	    return 0;

	}

      __sched_yield ();

    }

}