xref: /linux/tools/testing/selftests/timers/nanosleep.c (revision c34e9ab9a612ee8b18273398ef75c207b01f516d)
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 <include/vdso/time64.h>
31 #include "../kselftest.h"
32 
33 /* CLOCK_HWSPECIFIC == CLOCK_SGI_CYCLE (Deprecated) */
34 #define CLOCK_HWSPECIFIC		10
35 
36 #define UNSUPPORTED 0xf00f
37 
38 char *clockstring(int clockid)
39 {
40 	switch (clockid) {
41 	case CLOCK_REALTIME:
42 		return "CLOCK_REALTIME";
43 	case CLOCK_MONOTONIC:
44 		return "CLOCK_MONOTONIC";
45 	case CLOCK_PROCESS_CPUTIME_ID:
46 		return "CLOCK_PROCESS_CPUTIME_ID";
47 	case CLOCK_THREAD_CPUTIME_ID:
48 		return "CLOCK_THREAD_CPUTIME_ID";
49 	case CLOCK_MONOTONIC_RAW:
50 		return "CLOCK_MONOTONIC_RAW";
51 	case CLOCK_REALTIME_COARSE:
52 		return "CLOCK_REALTIME_COARSE";
53 	case CLOCK_MONOTONIC_COARSE:
54 		return "CLOCK_MONOTONIC_COARSE";
55 	case CLOCK_BOOTTIME:
56 		return "CLOCK_BOOTTIME";
57 	case CLOCK_REALTIME_ALARM:
58 		return "CLOCK_REALTIME_ALARM";
59 	case CLOCK_BOOTTIME_ALARM:
60 		return "CLOCK_BOOTTIME_ALARM";
61 	case CLOCK_TAI:
62 		return "CLOCK_TAI";
63 	};
64 	return "UNKNOWN_CLOCKID";
65 }
66 
67 /* returns 1 if a <= b, 0 otherwise */
68 static inline int in_order(struct timespec a, struct timespec b)
69 {
70 	if (a.tv_sec < b.tv_sec)
71 		return 1;
72 	if (a.tv_sec > b.tv_sec)
73 		return 0;
74 	if (a.tv_nsec > b.tv_nsec)
75 		return 0;
76 	return 1;
77 }
78 
79 struct timespec timespec_add(struct timespec ts, unsigned long long ns)
80 {
81 	ts.tv_nsec += ns;
82 	while (ts.tv_nsec >= NSEC_PER_SEC) {
83 		ts.tv_nsec -= NSEC_PER_SEC;
84 		ts.tv_sec++;
85 	}
86 	return ts;
87 }
88 
89 int nanosleep_test(int clockid, long long ns)
90 {
91 	struct timespec now, target, rel;
92 
93 	/* First check abs time */
94 	if (clock_gettime(clockid, &now))
95 		return UNSUPPORTED;
96 	target = timespec_add(now, ns);
97 
98 	if (clock_nanosleep(clockid, TIMER_ABSTIME, &target, NULL))
99 		return UNSUPPORTED;
100 	clock_gettime(clockid, &now);
101 
102 	if (!in_order(target, now))
103 		return -1;
104 
105 	/* Second check reltime */
106 	clock_gettime(clockid, &now);
107 	rel.tv_sec = 0;
108 	rel.tv_nsec = 0;
109 	rel = timespec_add(rel, ns);
110 	target = timespec_add(now, ns);
111 	clock_nanosleep(clockid, 0, &rel, NULL);
112 	clock_gettime(clockid, &now);
113 
114 	if (!in_order(target, now))
115 		return -1;
116 	return 0;
117 }
118 
119 int main(int argc, char **argv)
120 {
121 	long long length;
122 	int clockid, ret;
123 	int max_clocks = CLOCK_TAI + 1;
124 
125 	ksft_print_header();
126 	ksft_set_plan(max_clocks);
127 
128 	for (clockid = CLOCK_REALTIME; clockid < max_clocks; clockid++) {
129 
130 		/* Skip cputime clockids since nanosleep won't increment cputime */
131 		if (clockid == CLOCK_PROCESS_CPUTIME_ID ||
132 				clockid == CLOCK_THREAD_CPUTIME_ID ||
133 				clockid == CLOCK_HWSPECIFIC) {
134 			ksft_test_result_skip("%-31s\n", clockstring(clockid));
135 			continue;
136 		}
137 
138 		fflush(stdout);
139 
140 		length = 10;
141 		while (length <= (NSEC_PER_SEC * 10)) {
142 			ret = nanosleep_test(clockid, length);
143 			if (ret == UNSUPPORTED) {
144 				ksft_test_result_skip("%-31s\n", clockstring(clockid));
145 				goto next;
146 			}
147 			if (ret < 0) {
148 				ksft_test_result_fail("%-31s\n", clockstring(clockid));
149 				ksft_exit_fail();
150 			}
151 			length *= 100;
152 		}
153 		ksft_test_result_pass("%-31s\n", clockstring(clockid));
154 next:
155 		ret = 0;
156 	}
157 	ksft_exit_pass();
158 }
159