1 /* Make sure timers don't return early 2 * by: john stultz (johnstul@us.ibm.com) 3 * John Stultz (john.stultz@linaro.org) 4 * (C) Copyright IBM 2012 5 * (C) Copyright Linaro 2013 2015 6 * Licensed under the GPLv2 7 * 8 * To build: 9 * $ gcc nanosleep.c -o nanosleep -lrt 10 * 11 * This program is free software: you can redistribute it and/or modify 12 * it under the terms of the GNU General Public License as published by 13 * the Free Software Foundation, either version 2 of the License, or 14 * (at your option) any later version. 15 * 16 * This program is distributed in the hope that it will be useful, 17 * but WITHOUT ANY WARRANTY; without even the implied warranty of 18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 19 * GNU General Public License for more details. 20 */ 21 22 #include <errno.h> 23 #include <stdio.h> 24 #include <stdlib.h> 25 #include <time.h> 26 #include <sys/time.h> 27 #include <sys/timex.h> 28 #include <string.h> 29 #include <signal.h> 30 #include "../kselftest.h" 31 32 #define NSEC_PER_SEC 1000000000ULL 33 34 #define CLOCK_REALTIME 0 35 #define CLOCK_MONOTONIC 1 36 #define CLOCK_PROCESS_CPUTIME_ID 2 37 #define CLOCK_THREAD_CPUTIME_ID 3 38 #define CLOCK_MONOTONIC_RAW 4 39 #define CLOCK_REALTIME_COARSE 5 40 #define CLOCK_MONOTONIC_COARSE 6 41 #define CLOCK_BOOTTIME 7 42 #define CLOCK_REALTIME_ALARM 8 43 #define CLOCK_BOOTTIME_ALARM 9 44 #define CLOCK_HWSPECIFIC 10 45 #define CLOCK_TAI 11 46 #define NR_CLOCKIDS 12 47 48 #define UNSUPPORTED 0xf00f 49 50 char *clockstring(int clockid) 51 { 52 switch (clockid) { 53 case CLOCK_REALTIME: 54 return "CLOCK_REALTIME"; 55 case CLOCK_MONOTONIC: 56 return "CLOCK_MONOTONIC"; 57 case CLOCK_PROCESS_CPUTIME_ID: 58 return "CLOCK_PROCESS_CPUTIME_ID"; 59 case CLOCK_THREAD_CPUTIME_ID: 60 return "CLOCK_THREAD_CPUTIME_ID"; 61 case CLOCK_MONOTONIC_RAW: 62 return "CLOCK_MONOTONIC_RAW"; 63 case CLOCK_REALTIME_COARSE: 64 return "CLOCK_REALTIME_COARSE"; 65 case CLOCK_MONOTONIC_COARSE: 66 return "CLOCK_MONOTONIC_COARSE"; 67 case CLOCK_BOOTTIME: 68 return "CLOCK_BOOTTIME"; 69 case CLOCK_REALTIME_ALARM: 70 return "CLOCK_REALTIME_ALARM"; 71 case CLOCK_BOOTTIME_ALARM: 72 return "CLOCK_BOOTTIME_ALARM"; 73 case CLOCK_TAI: 74 return "CLOCK_TAI"; 75 }; 76 return "UNKNOWN_CLOCKID"; 77 } 78 79 /* returns 1 if a <= b, 0 otherwise */ 80 static inline int in_order(struct timespec a, struct timespec b) 81 { 82 if (a.tv_sec < b.tv_sec) 83 return 1; 84 if (a.tv_sec > b.tv_sec) 85 return 0; 86 if (a.tv_nsec > b.tv_nsec) 87 return 0; 88 return 1; 89 } 90 91 struct timespec timespec_add(struct timespec ts, unsigned long long ns) 92 { 93 ts.tv_nsec += ns; 94 while (ts.tv_nsec >= NSEC_PER_SEC) { 95 ts.tv_nsec -= NSEC_PER_SEC; 96 ts.tv_sec++; 97 } 98 return ts; 99 } 100 101 int nanosleep_test(int clockid, long long ns) 102 { 103 struct timespec now, target, rel; 104 105 /* First check abs time */ 106 if (clock_gettime(clockid, &now)) 107 return UNSUPPORTED; 108 target = timespec_add(now, ns); 109 110 if (clock_nanosleep(clockid, TIMER_ABSTIME, &target, NULL)) 111 return UNSUPPORTED; 112 clock_gettime(clockid, &now); 113 114 if (!in_order(target, now)) 115 return -1; 116 117 /* Second check reltime */ 118 clock_gettime(clockid, &now); 119 rel.tv_sec = 0; 120 rel.tv_nsec = 0; 121 rel = timespec_add(rel, ns); 122 target = timespec_add(now, ns); 123 clock_nanosleep(clockid, 0, &rel, NULL); 124 clock_gettime(clockid, &now); 125 126 if (!in_order(target, now)) 127 return -1; 128 return 0; 129 } 130 131 int main(int argc, char **argv) 132 { 133 long long length; 134 int clockid, ret; 135 136 for (clockid = CLOCK_REALTIME; clockid < NR_CLOCKIDS; clockid++) { 137 138 /* Skip cputime clockids since nanosleep won't increment cputime */ 139 if (clockid == CLOCK_PROCESS_CPUTIME_ID || 140 clockid == CLOCK_THREAD_CPUTIME_ID || 141 clockid == CLOCK_HWSPECIFIC) 142 continue; 143 144 printf("Nanosleep %-31s ", clockstring(clockid)); 145 146 length = 10; 147 while (length <= (NSEC_PER_SEC * 10)) { 148 ret = nanosleep_test(clockid, length); 149 if (ret == UNSUPPORTED) { 150 printf("[UNSUPPORTED]\n"); 151 goto next; 152 } 153 if (ret < 0) { 154 printf("[FAILED]\n"); 155 return ksft_exit_fail(); 156 } 157 length *= 100; 158 } 159 printf("[OK]\n"); 160 next: 161 ret = 0; 162 } 163 return ksft_exit_pass(); 164 } 165