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
9 * $ gcc nanosleep.c -o nanosleep -lrt
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.
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.
27 #include <sys/timex.h>
31 #include "../kselftest.h"
33 static inline int ksft_exit_pass(void)
37 static inline int ksft_exit_fail(void)
43 #define NSEC_PER_SEC 1000000000ULL
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
57 #define NR_CLOCKIDS 12
59 #define UNSUPPORTED 0xf00f
61 char *clockstring(int clockid)
65 return "CLOCK_REALTIME";
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";
79 return "CLOCK_BOOTTIME";
80 case CLOCK_REALTIME_ALARM:
81 return "CLOCK_REALTIME_ALARM";
82 case CLOCK_BOOTTIME_ALARM:
83 return "CLOCK_BOOTTIME_ALARM";
87 return "UNKNOWN_CLOCKID";
90 /* returns 1 if a <= b, 0 otherwise */
91 static inline int in_order(struct timespec a, struct timespec b)
93 if (a.tv_sec < b.tv_sec)
95 if (a.tv_sec > b.tv_sec)
97 if (a.tv_nsec > b.tv_nsec)
102 struct timespec timespec_add(struct timespec ts, unsigned long long ns)
105 while (ts.tv_nsec >= NSEC_PER_SEC) {
106 ts.tv_nsec -= NSEC_PER_SEC;
112 int nanosleep_test(int clockid, long long ns)
114 struct timespec now, target, rel;
116 /* First check abs time */
117 if (clock_gettime(clockid, &now))
119 target = timespec_add(now, ns);
121 if (clock_nanosleep(clockid, TIMER_ABSTIME, &target, NULL))
123 clock_gettime(clockid, &now);
125 if (!in_order(target, now))
128 /* Second check reltime */
129 clock_gettime(clockid, &now);
132 rel = timespec_add(rel, ns);
133 target = timespec_add(now, ns);
134 clock_nanosleep(clockid, 0, &rel, NULL);
135 clock_gettime(clockid, &now);
137 if (!in_order(target, now))
142 int main(int argc, char **argv)
147 for (clockid = CLOCK_REALTIME; clockid < NR_CLOCKIDS; clockid++) {
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)
155 printf("Nanosleep %-31s ", clockstring(clockid));
158 while (length <= (NSEC_PER_SEC * 10)) {
159 ret = nanosleep_test(clockid, length);
160 if (ret == UNSUPPORTED) {
161 printf("[UNSUPPORTED]\n");
165 printf("[FAILED]\n");
166 return ksft_exit_fail();
174 return ksft_exit_pass();