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1/*2 * Copyright © 2018 Alexey Dobriyan <adobriyan@gmail.com>3 *4 * Permission to use, copy, modify, and distribute this software for any5 * purpose with or without fee is hereby granted, provided that the above6 * copyright notice and this permission notice appear in all copies.7 *8 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES9 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF10 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR11 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES12 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN13 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF14 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.15 */16// Test that boottime value in /proc/uptime and CLOCK_BOOTTIME increment17// monotonically. We don't test idle time monotonicity due to broken iowait18// task counting, cf: comment above get_cpu_idle_time_us()19#undef NDEBUG20#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}59