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

DEFINITIONS

1. clockstring
2. in_order
3. timespec_add
4. nanosleep_test
5. main

   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                 fflush(stdout);
 146 
 147                 length = 10;
 148                 while (length <= (NSEC_PER_SEC * 10)) {
 149                         ret = nanosleep_test(clockid, length);
 150                         if (ret == UNSUPPORTED) {
 151                                 printf("[UNSUPPORTED]\n");
 152                                 goto next;
 153                         }
 154                         if (ret < 0) {
 155                                 printf("[FAILED]\n");
 156                                 return ksft_exit_fail();
 157                         }
 158                         length *= 100;
 159                 }
 160                 printf("[OK]\n");
 161 next:
 162                 ret = 0;
 163         }
 164         return ksft_exit_pass();
 165 }