/* pthread_barrier_wait.  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 <assert.h>

#include <pt-internal.h>

int

pthread_barrier_wait (pthread_barrier_t *barrier)

{

  __pthread_spin_lock (&barrier->__lock);

  if (--barrier->__pending == 0)

    {

      barrier->__pending = barrier->__count;

      if (barrier->__count > 1)

	{

	  struct __pthread *wakeup;

	  unsigned n = 0;

	  __pthread_queue_iterate (barrier->__queue, wakeup)

	    n++;

	  {

	    struct __pthread *wakeups[n];

	    unsigned i = 0;

	    __pthread_dequeuing_iterate (barrier->__queue, wakeup)

	      wakeups[i++] = wakeup;

	    barrier->__queue = NULL;

	    __pthread_spin_unlock (&barrier->__lock);

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

	      __pthread_wakeup (wakeups[i]);

	  }

	}

      return PTHREAD_BARRIER_SERIAL_THREAD;

    }

  else

    {

      struct __pthread *self = _pthread_self ();

      /* Add ourselves to the list of waiters.  */

      __pthread_enqueue (&barrier->__queue, self);

      __pthread_spin_unlock (&barrier->__lock);

      __pthread_block (self);

      return 0;

    }

}