/* Timed low level locking for pthread library.  Generic futex-using version.

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

   This file is part of the GNU C Library.

   Contributed by Paul Mackerras <paulus@au.ibm.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 <atomic.h>

#include <errno.h>

#include <lowlevellock.h>

#include <sys/time.h>

int

__lll_timedlock_wait (int *futex, const struct timespec *abstime, int private)

{

  /* Reject invalid timeouts.  */

  if (abstime->tv_nsec < 0 || abstime->tv_nsec >= 1000000000)

    return EINVAL;

  /* Try locking.  */

  while (atomic_exchange_acq (futex, 2) != 0)

    {

      struct timeval tv;

      /* Get the current time.  */

      (void) __gettimeofday (&tv, NULL);

      /* Compute relative timeout.  */

      struct timespec rt;

      rt.tv_sec = abstime->tv_sec - tv.tv_sec;

      rt.tv_nsec = abstime->tv_nsec - tv.tv_usec * 1000;

      if (rt.tv_nsec < 0)

        {

          rt.tv_nsec += 1000000000;

          --rt.tv_sec;

        }

      if (rt.tv_sec < 0)

        return ETIMEDOUT;

      /* If *futex == 2, wait until woken or timeout.  */

      lll_futex_timed_wait (futex, 2, &rt, private);

    }

  return 0;

}