/* nanosleep -- sleep for a period specified with a struct timespec
   Copyright (C) 2002-2014 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 <errno.h>
#include <mach.h>
#include <sys/time.h>
#include <unistd.h>

int
__nanosleep (const struct timespec *requested_time,
	     struct timespec *remaining)
{
  mach_port_t recv;
  struct timeval before, after;

  if (requested_time->tv_sec < 0
      || requested_time->tv_nsec < 0
      || requested_time->tv_nsec >= 1000000000)
    {
      errno = EINVAL;
      return -1;
    }

  const mach_msg_timeout_t ms
    = requested_time->tv_sec * 1000
    + (requested_time->tv_nsec + 999999) / 1000000;

  recv = __mach_reply_port ();

  if (remaining && __gettimeofday (&before, NULL) < 0)
    return -1;
  error_t err = __mach_msg (NULL, MACH_RCV_MSG|MACH_RCV_TIMEOUT|MACH_RCV_INTERRUPT,
			    0, 0, recv, ms, MACH_PORT_NULL);
  __mach_port_destroy (mach_task_self (), recv);
  if (err == EMACH_RCV_INTERRUPTED)
    {
      if (remaining && __gettimeofday (&after, NULL) >= 0)
	{
	  struct timeval req_time, elapsed, rem;
	  TIMESPEC_TO_TIMEVAL (&req_time, requested_time);
	  timersub (&after, &before, &elapsed);
	  timersub (&req_time, &elapsed, &rem);
	  TIMEVAL_TO_TIMESPEC (&rem, remaining);
	}

      errno = EINTR;
      return -1;
    }

  return 0;
}
libc_hidden_def (__nanosleep)
weak_alias (__nanosleep, nanosleep)