xref: /linux/tools/testing/selftests/timers/nanosleep.c (revision 7fc2cd2e4b398c57c9cf961cfea05eadbf34c05c)
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 static void dummy_event_handler(int val)
120 {
121 	/* No action needed */
122 }
123 
124 static int nanosleep_test_remaining(int clockid)
125 {
126 	struct timespec rqtp = {}, rmtp = {};
127 	struct itimerspec itimer = {};
128 	struct sigaction sa = {};
129 	timer_t timer;
130 	int ret;
131 
132 	sa.sa_handler = dummy_event_handler;
133 	ret = sigaction(SIGALRM, &sa, NULL);
134 	if (ret)
135 		return -1;
136 
137 	ret = timer_create(clockid, NULL, &timer);
138 	if (ret)
139 		return -1;
140 
141 	itimer.it_value.tv_nsec = NSEC_PER_SEC / 4;
142 	ret = timer_settime(timer, 0, &itimer, NULL);
143 	if (ret)
144 		return -1;
145 
146 	rqtp.tv_nsec = NSEC_PER_SEC / 2;
147 	ret = clock_nanosleep(clockid, 0, &rqtp, &rmtp);
148 	if (ret != EINTR)
149 		return -1;
150 
151 	ret = timer_delete(timer);
152 	if (ret)
153 		return -1;
154 
155 	sa.sa_handler = SIG_DFL;
156 	ret = sigaction(SIGALRM, &sa, NULL);
157 	if (ret)
158 		return -1;
159 
160 	if (!in_order((struct timespec) {}, rmtp))
161 		return -1;
162 
163 	if (!in_order(rmtp, rqtp))
164 		return -1;
165 
166 	return 0;
167 }
168 
169 int main(int argc, char **argv)
170 {
171 	long long length;
172 	int clockid, ret;
173 	int max_clocks = CLOCK_TAI + 1;
174 
175 	ksft_print_header();
176 	ksft_set_plan(max_clocks);
177 
178 	for (clockid = CLOCK_REALTIME; clockid < max_clocks; clockid++) {
179 
180 		/* Skip cputime clockids since nanosleep won't increment cputime */
181 		if (clockid == CLOCK_PROCESS_CPUTIME_ID ||
182 				clockid == CLOCK_THREAD_CPUTIME_ID ||
183 				clockid == CLOCK_HWSPECIFIC) {
184 			ksft_test_result_skip("%-31s\n", clockstring(clockid));
185 			continue;
186 		}
187 
188 		fflush(stdout);
189 
190 		length = 10;
191 		while (length <= (NSEC_PER_SEC * 10)) {
192 			ret = nanosleep_test(clockid, length);
193 			if (ret == UNSUPPORTED) {
194 				ksft_test_result_skip("%-31s\n", clockstring(clockid));
195 				goto next;
196 			}
197 			if (ret < 0) {
198 				ksft_test_result_fail("%-31s\n", clockstring(clockid));
199 				ksft_exit_fail();
200 			}
201 			length *= 100;
202 		}
203 		ret = nanosleep_test_remaining(clockid);
204 		if (ret < 0) {
205 			ksft_test_result_fail("%-31s\n", clockstring(clockid));
206 			ksft_exit_fail();
207 		}
208 		ksft_test_result_pass("%-31s\n", clockstring(clockid));
209 next:
210 		ret = 0;
211 	}
212 	ksft_exit_pass();
213 }
214