xref: /freebsd/lib/libc/gen/sleep.c (revision f4b37ed0f8b307b1f3f0f630ca725d68f1dff30d)
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("$FreeBSD$");
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 #include "libc_private.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 (((int (*)(const struct timespec *, struct timespec *))
61 	    __libc_interposing[INTERPOS_nanosleep])(
62 	    &time_to_sleep, &time_remaining) != -1)
63 		return (0);
64 	if (errno != EINTR)
65 		return (seconds);		/* best guess */
66 	return (time_remaining.tv_sec +
67 	    (time_remaining.tv_nsec != 0)); /* round up */
68 }
69 
70 __weak_reference(__sleep, sleep);
71 __weak_reference(__sleep, _sleep);
72