linux-zen-server/tools/testing/selftests/proc/proc-uptime-001.c

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2023-08-30 17:53:23 +02:00
/*
* Copyright © 2018 Alexey Dobriyan <adobriyan@gmail.com>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
// Test that values in /proc/uptime increment monotonically.
#undef NDEBUG
#include <assert.h>
#include <stdint.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include "proc-uptime.h"
int main(void)
{
uint64_t start, u0, u1, i0, i1;
int fd;
fd = open("/proc/uptime", O_RDONLY);
assert(fd >= 0);
proc_uptime(fd, &u0, &i0);
start = u0;
do {
proc_uptime(fd, &u1, &i1);
assert(u1 >= u0);
assert(i1 >= i0);
u0 = u1;
i0 = i1;
} while (u1 - start < 100);
return 0;
}