sysdeps/mach/usleep.c

   1 /* Copyright (C) 1992, 1993, 1994 Free Software Foundation, Inc.
   2 This file is part of the GNU C Library.
   3
   4 The GNU C Library is free software; you can redistribute it and/or
   5 modify it under the terms of the GNU Library General Public License as
   6 published by the Free Software Foundation; either version 2 of the
   7 License, or (at your option) any later version.
   8
   9 The GNU C Library is distributed in the hope that it will be useful,
  10 but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12 Library General Public License for more details.
  13
  14 You should have received a copy of the GNU Library General Public
  15 License along with the GNU C Library; see the file COPYING.LIB.  If
  16 not, write to the Free Software Foundation, Inc., 675 Mass Ave,
  17 Cambridge, MA 02139, USA.  */
  18
  19 #include <ansidecl.h>
  20 #include <errno.h>
  21 #include <mach.h>
  22 #include <sys/time.h>
  23
  24 /* Sleep USECONDS microseconds, or until a previously set timer goes off.  */
  25 unsigned int
  26 DEFUN(usleep, (useconds), unsigned int useconds)
  27 {
  28   mach_port_t recv;
  29   struct timeval before, after;
  30
  31   recv = __mach_reply_port ();
  32
  33   if (__gettimeofday (&before, NULL) < 0)
  34     return useconds;
  35   (void) __mach_msg (NULL, MACH_RCV_MSG|MACH_RCV_TIMEOUT|MACH_RCV_INTERRUPT,
  36                      0, 0, recv, (useconds + 999) / 1000, MACH_PORT_NULL);
  37   __mach_port_destroy (mach_task_self (), recv);
  38   if (__gettimeofday (&after, NULL) < 0)
  39     return 0;
  40
  41   return useconds - (((after.tv_sec - before.tv_sec) * 1000000) +
  42                      (after.tv_usec - before.tv_usec));
  43 }