LXR linux/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#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
  50char *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 */
  80static 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
  91struct 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
 101int 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
 131int 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");
 161next:
 162                ret = 0;
 163        }
 164        return ksft_exit_pass();
 165}
 166