1 /* $OpenBSD: test_time_skew.c,v 1.1 2020/07/06 13:33:06 pirofti Exp $ */
2 /*
3 * Copyright (c) 2020 Paul Irofti <paul@irofti.net>
4 *
5 * Permission to use, copy, modify, and distribute this software for any
6 * purpose with or without fee is hereby granted, provided that the above
7 * copyright notice and this permission notice appear in all copies.
8 *
9 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
10 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
12 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
15 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
16 */
17
18 #include <sys/time.h>
19
20 #include <assert.h>
21 #include <time.h>
22 #include <stdlib.h>
23 #include <stdio.h>
24
25 #define ASSERT_EQ(a, b) assert((a) == (b))
26 #define ASSERT_NE(a, b) assert((a) != (b))
27
28 void
check()29 check()
30 {
31 struct timespec tp1, tp2, tout;
32
33 tout.tv_sec = 0;
34 tout.tv_nsec = 100000;
35
36 ASSERT_EQ(0, clock_gettime(CLOCK_MONOTONIC, &tp1));
37
38 nanosleep(&tout, NULL);
39
40 ASSERT_EQ(0, clock_gettime(CLOCK_MONOTONIC, &tp2));
41
42 /* tp1 should never be larger than tp2 */
43 ASSERT_NE(1, timespeccmp(&tp1, &tp2, >));
44 }
45
46 int
main(void)47 main(void)
48 {
49 int i;
50
51 for (i = 0; i < 1000; i++)
52 check();
53
54 return 0;
55 }
56