kernel/tools/testing/selftests/timers/nanosleep.c

   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 }