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. All advertising materials mentioning features or use of this software
  14  *    must display the following acknowledgement:
  15  *      This product includes software developed by the University of
  16  *      California, Berkeley and its contributors.
  17  * 4. Neither the name of the University nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  *
  33  * @(#)sleep.c  8.1 (Berkeley) 6/4/93
  34  * $FreeBSD: src/lib/libc/gen/sleep.c,v 1.28.2.1 2000/03/18 23:13:24 jasone Exp $
  35  * $DragonFly: src/lib/libc/gen/sleep.c,v 1.4 2005/11/13 00:07:42 swildner Exp $
  36  */
  37
  38 #include "namespace.h"
  39 #include <errno.h>
  40 #include <limits.h>
  41 #include <time.h>
  42 #include <unistd.h>
  43 #include "un-namespace.h"
  44
  45 unsigned int
  46 __sleep(unsigned int seconds)
  47 {
  48         struct timespec time_to_sleep;
  49         struct timespec time_remaining;
  50
  51         /*
  52          * Avoid overflow when `seconds' is huge.  This assumes that
  53          * the maximum value for a time_t is >= INT_MAX.
  54          */
  55         if (seconds > INT_MAX)
  56                 return (seconds - INT_MAX + __sleep(INT_MAX));
  57
  58         time_to_sleep.tv_sec = seconds;
  59         time_to_sleep.tv_nsec = 0;
  60         if (_nanosleep(&time_to_sleep, &time_remaining) != -1)
  61                 return (0);
  62         if (errno != EINTR)
  63                 return (seconds);               /* best guess */
  64         return (time_remaining.tv_sec +
  65                 (time_remaining.tv_nsec != 0)); /* round up */
  66 }
  67
  68 __weak_reference(__sleep, sleep);
  69 __weak_reference(__sleep, _sleep);
  70