gen/FreeBSD/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  * 4. 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
  30 #if defined(LIBC_SCCS) && !defined(lint)
  31 static char sccsid[] = "@(#)sleep.c     8.1 (Berkeley) 6/4/93";
  32 #endif /* LIBC_SCCS and not lint */
  33 #include <sys/cdefs.h>
  34 __FBSDID("$FreeBSD: src/lib/libc/gen/sleep.c,v 1.33 2009/12/05 19:31:38 ed Exp $");
  35
  36 #include "namespace.h"
  37 #include <errno.h>
  38 #include <limits.h>
  39 #include <time.h>
  40 #include <unistd.h>
  41 #include "un-namespace.h"
  42
  43 unsigned int
  44 __sleep(unsigned int seconds)
  45 {
  46         struct timespec time_to_sleep;
  47         struct timespec time_remaining;
  48
  49         /*
  50          * Avoid overflow when `seconds' is huge.  This assumes that
  51          * the maximum value for a time_t is >= INT_MAX.
  52          */
  53         if (seconds > INT_MAX)
  54                 return (seconds - INT_MAX + __sleep(INT_MAX));
  55
  56         time_to_sleep.tv_sec = seconds;
  57         time_to_sleep.tv_nsec = 0;
  58         if (_nanosleep(&time_to_sleep, &time_remaining) != -1)
  59                 return (0);
  60         if (errno != EINTR)
  61                 return (seconds);               /* best guess */
  62         return (time_remaining.tv_sec +
  63                 (time_remaining.tv_nsec != 0)); /* round up */
  64 }
  65
  66 __weak_reference(__sleep, sleep);
  67 __weak_reference(__sleep, _sleep);