1/*
 2 * Copyright © 2018 Alexey Dobriyan <adobriyan@gmail.com>
 3 *
 4 * Permission to use, copy, modify, and distribute this software for any
 5 * purpose with or without fee is hereby granted, provided that the above
 6 * copyright notice and this permission notice appear in all copies.
 7 *
 8 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 9 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15 */
16// Test that boottime value in /proc/uptime and CLOCK_BOOTTIME increment
17// monotonically. We don't test idle time monotonicity due to broken iowait
18// task counting, cf: comment above get_cpu_idle_time_us()
19#undef NDEBUG
20#include <assert.h>
21#include <stdint.h>
22#include <sys/types.h>
23#include <sys/stat.h>
24#include <fcntl.h>
25
26#include "proc-uptime.h"
27
28int main(void)
29{
30	uint64_t start, u0, u1, c0, c1;
31	int fd;
32
33	fd = open("/proc/uptime", O_RDONLY);
34	assert(fd >= 0);
35
36	u0 = proc_uptime(fd);
37	start = u0;
38	c0 = clock_boottime();
39
40	do {
41		u1 = proc_uptime(fd);
42		c1 = clock_boottime();
43
44		/* Is /proc/uptime monotonic ? */
45		assert(u1 >= u0);
46
47		/* Is CLOCK_BOOTTIME monotonic ? */
48		assert(c1 >= c0);
49
50		/* Is CLOCK_BOOTTIME VS /proc/uptime monotonic ? */
51		assert(c0 >= u0);
52
53		u0 = u1;
54		c0 = c1;
55	} while (u1 - start < 100);
56
57	return 0;
58}