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 <stdio.h> 23 #include <stdlib.h> 24 #include <time.h> 25 #include <sys/time.h> 26 #include <sys/timex.h> 27 #include <string.h> 28 #include <signal.h> 29 #ifdef KTEST 30 #include "../kselftest.h" 31 #else 32 static inline int ksft_exit_pass(void) 33 { 34 exit(0); 35 } 36 static inline int ksft_exit_fail(void) 37 { 38 exit(1); 39 } 40 #endif 41 42 #define NSEC_PER_SEC 1000000000ULL 43 44 #define CLOCK_REALTIME 0 45 #define CLOCK_MONOTONIC 1 46 #define CLOCK_PROCESS_CPUTIME_ID 2 47 #define CLOCK_THREAD_CPUTIME_ID 3 48 #define CLOCK_MONOTONIC_RAW 4 49 #define CLOCK_REALTIME_COARSE 5 50 #define CLOCK_MONOTONIC_COARSE 6 51 #define CLOCK_BOOTTIME 7 52 #define CLOCK_REALTIME_ALARM 8 53 #define CLOCK_BOOTTIME_ALARM 9 54 #define CLOCK_HWSPECIFIC 10 55 #define CLOCK_TAI 11 56 #define NR_CLOCKIDS 12 57 58 #define UNSUPPORTED 0xf00f 59 60 char *clockstring(int clockid) 61 { 62 switch (clockid) { 63 case CLOCK_REALTIME: 64 return "CLOCK_REALTIME"; 65 case CLOCK_MONOTONIC: 66 return "CLOCK_MONOTONIC"; 67 case CLOCK_PROCESS_CPUTIME_ID: 68 return "CLOCK_PROCESS_CPUTIME_ID"; 69 case CLOCK_THREAD_CPUTIME_ID: 70 return "CLOCK_THREAD_CPUTIME_ID"; 71 case CLOCK_MONOTONIC_RAW: 72 return "CLOCK_MONOTONIC_RAW"; 73 case CLOCK_REALTIME_COARSE: 74 return "CLOCK_REALTIME_COARSE"; 75 case CLOCK_MONOTONIC_COARSE: 76 return "CLOCK_MONOTONIC_COARSE"; 77 case CLOCK_BOOTTIME: 78 return "CLOCK_BOOTTIME"; 79 case CLOCK_REALTIME_ALARM: 80 return "CLOCK_REALTIME_ALARM"; 81 case CLOCK_BOOTTIME_ALARM: 82 return "CLOCK_BOOTTIME_ALARM"; 83 case CLOCK_TAI: 84 return "CLOCK_TAI"; 85 }; 86 return "UNKNOWN_CLOCKID"; 87 } 88 89 /* returns 1 if a <= b, 0 otherwise */ 90 static inline int in_order(struct timespec a, struct timespec b) 91 { 92 if (a.tv_sec < b.tv_sec) 93 return 1; 94 if (a.tv_sec > b.tv_sec) 95 return 0; 96 if (a.tv_nsec > b.tv_nsec) 97 return 0; 98 return 1; 99 } 100 101 struct timespec timespec_add(struct timespec ts, unsigned long long ns) 102 { 103 ts.tv_nsec += ns; 104 while (ts.tv_nsec >= NSEC_PER_SEC) { 105 ts.tv_nsec -= NSEC_PER_SEC; 106 ts.tv_sec++; 107 } 108 return ts; 109 } 110 111 int nanosleep_test(int clockid, long long ns) 112 { 113 struct timespec now, target, rel; 114 115 /* First check abs time */ 116 if (clock_gettime(clockid, &now)) 117 return UNSUPPORTED; 118 target = timespec_add(now, ns); 119 120 if (clock_nanosleep(clockid, TIMER_ABSTIME, &target, NULL)) 121 return UNSUPPORTED; 122 clock_gettime(clockid, &now); 123 124 if (!in_order(target, now)) 125 return -1; 126 127 /* Second check reltime */ 128 clock_gettime(clockid, &now); 129 rel.tv_sec = 0; 130 rel.tv_nsec = 0; 131 rel = timespec_add(rel, ns); 132 target = timespec_add(now, ns); 133 clock_nanosleep(clockid, 0, &rel, NULL); 134 clock_gettime(clockid, &now); 135 136 if (!in_order(target, now)) 137 return -1; 138 return 0; 139 } 140 141 int main(int argc, char **argv) 142 { 143 long long length; 144 int clockid, ret; 145 146 for (clockid = CLOCK_REALTIME; clockid < NR_CLOCKIDS; clockid++) { 147 148 /* Skip cputime clockids since nanosleep won't increment cputime */ 149 if (clockid == CLOCK_PROCESS_CPUTIME_ID || 150 clockid == CLOCK_THREAD_CPUTIME_ID || 151 clockid == CLOCK_HWSPECIFIC) 152 continue; 153 154 printf("Nanosleep %-31s ", clockstring(clockid)); 155 156 length = 10; 157 while (length <= (NSEC_PER_SEC * 10)) { 158 ret = nanosleep_test(clockid, length); 159 if (ret == UNSUPPORTED) { 160 printf("[UNSUPPORTED]\n"); 161 goto next; 162 } 163 if (ret < 0) { 164 printf("[FAILED]\n"); 165 return ksft_exit_fail(); 166 } 167 length *= 100; 168 } 169 printf("[OK]\n"); 170 next: 171 ret = 0; 172 } 173 return ksft_exit_pass(); 174 } 175