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 #ifdef KTEST 31 #include "../kselftest.h" 32 #else 33 static inline int ksft_exit_pass(void) 34 { 35 exit(0); 36 } 37 static inline int ksft_exit_fail(void) 38 { 39 exit(1); 40 } 41 #endif 42 43 #define NSEC_PER_SEC 1000000000ULL 44 45 #define CLOCK_REALTIME 0 46 #define CLOCK_MONOTONIC 1 47 #define CLOCK_PROCESS_CPUTIME_ID 2 48 #define CLOCK_THREAD_CPUTIME_ID 3 49 #define CLOCK_MONOTONIC_RAW 4 50 #define CLOCK_REALTIME_COARSE 5 51 #define CLOCK_MONOTONIC_COARSE 6 52 #define CLOCK_BOOTTIME 7 53 #define CLOCK_REALTIME_ALARM 8 54 #define CLOCK_BOOTTIME_ALARM 9 55 #define CLOCK_HWSPECIFIC 10 56 #define CLOCK_TAI 11 57 #define NR_CLOCKIDS 12 58 59 #define UNSUPPORTED 0xf00f 60 61 char *clockstring(int clockid) 62 { 63 switch (clockid) { 64 case CLOCK_REALTIME: 65 return "CLOCK_REALTIME"; 66 case CLOCK_MONOTONIC: 67 return "CLOCK_MONOTONIC"; 68 case CLOCK_PROCESS_CPUTIME_ID: 69 return "CLOCK_PROCESS_CPUTIME_ID"; 70 case CLOCK_THREAD_CPUTIME_ID: 71 return "CLOCK_THREAD_CPUTIME_ID"; 72 case CLOCK_MONOTONIC_RAW: 73 return "CLOCK_MONOTONIC_RAW"; 74 case CLOCK_REALTIME_COARSE: 75 return "CLOCK_REALTIME_COARSE"; 76 case CLOCK_MONOTONIC_COARSE: 77 return "CLOCK_MONOTONIC_COARSE"; 78 case CLOCK_BOOTTIME: 79 return "CLOCK_BOOTTIME"; 80 case CLOCK_REALTIME_ALARM: 81 return "CLOCK_REALTIME_ALARM"; 82 case CLOCK_BOOTTIME_ALARM: 83 return "CLOCK_BOOTTIME_ALARM"; 84 case CLOCK_TAI: 85 return "CLOCK_TAI"; 86 }; 87 return "UNKNOWN_CLOCKID"; 88 } 89 90 /* returns 1 if a <= b, 0 otherwise */ 91 static inline int in_order(struct timespec a, struct timespec b) 92 { 93 if (a.tv_sec < b.tv_sec) 94 return 1; 95 if (a.tv_sec > b.tv_sec) 96 return 0; 97 if (a.tv_nsec > b.tv_nsec) 98 return 0; 99 return 1; 100 } 101 102 struct timespec timespec_add(struct timespec ts, unsigned long long ns) 103 { 104 ts.tv_nsec += ns; 105 while (ts.tv_nsec >= NSEC_PER_SEC) { 106 ts.tv_nsec -= NSEC_PER_SEC; 107 ts.tv_sec++; 108 } 109 return ts; 110 } 111 112 int nanosleep_test(int clockid, long long ns) 113 { 114 struct timespec now, target, rel; 115 116 /* First check abs time */ 117 if (clock_gettime(clockid, &now)) 118 return UNSUPPORTED; 119 target = timespec_add(now, ns); 120 121 if (clock_nanosleep(clockid, TIMER_ABSTIME, &target, NULL)) 122 return UNSUPPORTED; 123 clock_gettime(clockid, &now); 124 125 if (!in_order(target, now)) 126 return -1; 127 128 /* Second check reltime */ 129 clock_gettime(clockid, &now); 130 rel.tv_sec = 0; 131 rel.tv_nsec = 0; 132 rel = timespec_add(rel, ns); 133 target = timespec_add(now, ns); 134 clock_nanosleep(clockid, 0, &rel, NULL); 135 clock_gettime(clockid, &now); 136 137 if (!in_order(target, now)) 138 return -1; 139 return 0; 140 } 141 142 int main(int argc, char **argv) 143 { 144 long long length; 145 int clockid, ret; 146 147 for (clockid = CLOCK_REALTIME; clockid < NR_CLOCKIDS; clockid++) { 148 149 /* Skip cputime clockids since nanosleep won't increment cputime */ 150 if (clockid == CLOCK_PROCESS_CPUTIME_ID || 151 clockid == CLOCK_THREAD_CPUTIME_ID || 152 clockid == CLOCK_HWSPECIFIC) 153 continue; 154 155 printf("Nanosleep %-31s ", clockstring(clockid)); 156 157 length = 10; 158 while (length <= (NSEC_PER_SEC * 10)) { 159 ret = nanosleep_test(clockid, length); 160 if (ret == UNSUPPORTED) { 161 printf("[UNSUPPORTED]\n"); 162 goto next; 163 } 164 if (ret < 0) { 165 printf("[FAILED]\n"); 166 return ksft_exit_fail(); 167 } 168 length *= 100; 169 } 170 printf("[OK]\n"); 171 next: 172 ret = 0; 173 } 174 return ksft_exit_pass(); 175 } 176