xref: /freebsd/lib/libc/gen/sleep.c (revision 1b6c2589164a3a7b2f62d4c28c2ffa1be860959e)
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 
34 #if defined(LIBC_SCCS) && !defined(lint)
35 #if 0
36 static char sccsid[] = "@(#)sleep.c	8.1 (Berkeley) 6/4/93";
37 #endif
38 static char rcsid[] =
39   "$FreeBSD$";
40 #endif /* LIBC_SCCS and not lint */
41 
42 #include "namespace.h"
43 #include <errno.h>
44 #include <limits.h>
45 #include <time.h>
46 #include <unistd.h>
47 #include "un-namespace.h"
48 
49 unsigned int
50 __sleep(seconds)
51 	unsigned int seconds;
52 {
53 	struct timespec time_to_sleep;
54 	struct timespec time_remaining;
55 
56 	/*
57 	 * Avoid overflow when `seconds' is huge.  This assumes that
58 	 * the maximum value for a time_t is >= INT_MAX.
59 	 */
60 	if (seconds > INT_MAX)
61 		return (seconds - INT_MAX + __sleep(INT_MAX));
62 
63 	time_to_sleep.tv_sec = seconds;
64 	time_to_sleep.tv_nsec = 0;
65 	if (_nanosleep(&time_to_sleep, &time_remaining) != -1)
66 		return (0);
67 	if (errno != EINTR)
68 		return (seconds);		/* best guess */
69 	return (time_remaining.tv_sec +
70 		(time_remaining.tv_nsec != 0)); /* round up */
71 }
72 
73 __weak_reference(__sleep, sleep);
74 __weak_reference(__sleep, _sleep);
75