/* * 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 boottime value in /proc/uptime and CLOCK_BOOTTIME increment // monotonically. We don't test idle time monotonicity due to broken iowait // task counting, cf: comment above get_cpu_idle_time_us() #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, c0, c1; int fd; fd = open("/proc/uptime", O_RDONLY); assert(fd >= 0); u0 = proc_uptime(fd); start = u0; c0 = clock_boottime(); do { u1 = proc_uptime(fd); c1 = clock_boottime(); /* Is /proc/uptime monotonic ? */ assert(u1 >= u0); /* Is CLOCK_BOOTTIME monotonic ? */ assert(c1 >= c0); /* Is CLOCK_BOOTTIME VS /proc/uptime monotonic ? */ assert(c0 >= u0); u0 = u1; c0 = c1; } while (u1 - start < 100); return 0; }