lib/libc/gen/sleep.c

   1 /*
   2  * Copyright (c) 1989, 1993
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. Neither the name of the University nor the names of its contributors
  14  *    may be used to endorse or promote products derived from this software
  15  *    without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  *
  29  * @(#)sleep.c  8.1 (Berkeley) 6/4/93
  30  * $FreeBSD: src/lib/libc/gen/sleep.c,v 1.28.2.1 2000/03/18 23:13:24 jasone Exp $
  31  */
  32
  33 #include "namespace.h"
  34 #include <errno.h>
  35 #include <limits.h>
  36 #include <time.h>
  37 #include <unistd.h>
  38 #include "un-namespace.h"
  39
  40 unsigned int
  41 __sleep(unsigned int seconds)
  42 {
  43         struct timespec time_to_sleep;
  44         struct timespec time_remaining;
  45
  46         /*
  47          * Avoid overflow when `seconds' is huge.  This assumes that
  48          * the maximum value for a time_t is >= INT_MAX.
  49          */
  50         if (seconds > INT_MAX)
  51                 return (seconds - INT_MAX + __sleep(INT_MAX));
  52
  53         time_to_sleep.tv_sec = seconds;
  54         time_to_sleep.tv_nsec = 0;
  55         if (_nanosleep(&time_to_sleep, &time_remaining) != -1)
  56                 return (0);
  57         if (errno != EINTR)
  58                 return (seconds);               /* best guess */
  59         return (time_remaining.tv_sec +
  60                 (time_remaining.tv_nsec != 0)); /* round up */
  61 }
  62
  63 __weak_reference(__sleep, sleep);
  64 __weak_reference(__sleep, _sleep);
  65