xref: /linux/tools/testing/selftests/timers/nanosleep.c (revision 24168c5e6dfbdd5b414f048f47f75d64533296ca)
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 
50 char *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 */
80 static 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 
91 struct 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 
101 int 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 
131 int main(int argc, char **argv)
132 {
133 	long long length;
134 	int clockid, ret;
135 
136 	ksft_print_header();
137 	ksft_set_plan(NR_CLOCKIDS);
138 
139 	for (clockid = CLOCK_REALTIME; clockid < NR_CLOCKIDS; clockid++) {
140 
141 		/* Skip cputime clockids since nanosleep won't increment cputime */
142 		if (clockid == CLOCK_PROCESS_CPUTIME_ID ||
143 				clockid == CLOCK_THREAD_CPUTIME_ID ||
144 				clockid == CLOCK_HWSPECIFIC) {
145 			ksft_test_result_skip("%-31s\n", clockstring(clockid));
146 			continue;
147 		}
148 
149 		fflush(stdout);
150 
151 		length = 10;
152 		while (length <= (NSEC_PER_SEC * 10)) {
153 			ret = nanosleep_test(clockid, length);
154 			if (ret == UNSUPPORTED) {
155 				ksft_test_result_skip("%-31s\n", clockstring(clockid));
156 				goto next;
157 			}
158 			if (ret < 0) {
159 				ksft_test_result_fail("%-31s\n", clockstring(clockid));
160 				ksft_exit_fail();
161 			}
162 			length *= 100;
163 		}
164 		ksft_test_result_pass("%-31s\n", clockstring(clockid));
165 next:
166 		ret = 0;
167 	}
168 	ksft_exit_pass();
169 }
170