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#ifdef KTEST
  31#include "../kselftest.h"
  32#else
  33static inline int ksft_exit_pass(void)
  34{
  35        exit(0);
  36}
  37static 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
  61char *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 */
  91static 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
 102struct 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
 112int 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
 142int 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");
 171next:
 172                ret = 0;
 173        }
 174        return ksft_exit_pass();
 175}
 176