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 28 int 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