sysdeps/unix/sysv/linux/usleep.c

   1 /* Implementation of the BSD usleep function using nanosleep.
   2    Copyright (C) 1996-2015 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4    Contributed by Ulrich Drepper <drepper@cygnus.com>, 1996.
   5
   6    The GNU C Library is free software; you can redistribute it and/or
   7    modify it under the terms of the GNU Lesser General Public
   8    License as published by the Free Software Foundation; either
   9    version 2.1 of the License, or (at your option) any later version.
  10
  11    The GNU C Library is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14    Lesser General Public License for more details.
  15
  16    You should have received a copy of the GNU Lesser General Public
  17    License along with the GNU C Library; if not, see
  18    <http://www.gnu.org/licenses/>.  */
  19
  20 #include <time.h>
  21 #include <unistd.h>
  22
  23 int
  24 usleep (useconds_t useconds)
  25 {
  26   struct timespec ts = { .tv_sec = (long int) (useconds / 1000000),
  27                          .tv_nsec = (long int) (useconds % 1000000) * 1000ul };
  28
  29   /* Note the usleep() is a cancellation point.  But since we call
  30      nanosleep() which itself is a cancellation point we do not have
  31      to do anything here.  */
  32   return __nanosleep (&ts, NULL);
  33 }