1/* Time inconsistency check test
2 * by: john stultz (johnstul@us.ibm.com)
3 * (C) Copyright IBM 2003, 2004, 2005, 2012
4 * (C) Copyright Linaro Limited 2015
5 * Licensed under the GPLv2
6 *
7 * To build:
8 * $ gcc inconsistency-check.c -o inconsistency-check -lrt
9 *
10 * This program is free software: you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License as published by
12 * the Free Software Foundation, either version 2 of the License, or
13 * (at your option) any later version.
14 *
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 * GNU General Public License for more details.
19 */
20
21
22
23#include <stdio.h>
24#include <unistd.h>
25#include <stdlib.h>
26#include <time.h>
27#include <sys/time.h>
28#include <sys/timex.h>
29#include <string.h>
30#include <signal.h>
31#include "../kselftest.h"
32
33#define CALLS_PER_LOOP 64
34#define NSEC_PER_SEC 1000000000ULL
35
36#define CLOCK_REALTIME 0
37#define CLOCK_MONOTONIC 1
38#define CLOCK_PROCESS_CPUTIME_ID 2
39#define CLOCK_THREAD_CPUTIME_ID 3
40#define CLOCK_MONOTONIC_RAW 4
41#define CLOCK_REALTIME_COARSE 5
42#define CLOCK_MONOTONIC_COARSE 6
43#define CLOCK_BOOTTIME 7
44#define CLOCK_REALTIME_ALARM 8
45#define CLOCK_BOOTTIME_ALARM 9
46#define CLOCK_HWSPECIFIC 10
47#define CLOCK_TAI 11
48#define NR_CLOCKIDS 12
49
50char *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 */
80static inline int in_order(struct timespec a, struct timespec b)
81{
82 /* use unsigned to avoid false positives on 2038 rollover */
83 if ((unsigned long)a.tv_sec < (unsigned long)b.tv_sec)
84 return 1;
85 if ((unsigned long)a.tv_sec > (unsigned long)b.tv_sec)
86 return 0;
87 if (a.tv_nsec > b.tv_nsec)
88 return 0;
89 return 1;
90}
91
92
93
94int consistency_test(int clock_type, unsigned long seconds)
95{
96 struct timespec list[CALLS_PER_LOOP];
97 int i, inconsistent;
98 long now, then;
99 time_t t;
100 char *start_str;
101
102 clock_gettime(clock_type, &list[0]);
103 now = then = list[0].tv_sec;
104
105 /* timestamp start of test */
106 t = time(0);
107 start_str = ctime(&t);
108
109 while (seconds == -1 || now - then < seconds) {
110 inconsistent = -1;
111
112 /* Fill list */
113 for (i = 0; i < CALLS_PER_LOOP; i++)
114 clock_gettime(clock_type, &list[i]);
115
116 /* Check for inconsistencies */
117 for (i = 0; i < CALLS_PER_LOOP - 1; i++)
118 if (!in_order(a: list[i], b: list[i+1]))
119 inconsistent = i;
120
121 /* display inconsistency */
122 if (inconsistent >= 0) {
123 unsigned long long delta;
124
125 ksft_print_msg(msg: "\%s\n", start_str);
126 for (i = 0; i < CALLS_PER_LOOP; i++) {
127 if (i == inconsistent)
128 ksft_print_msg(msg: "--------------------\n");
129 ksft_print_msg(msg: "%lu:%lu\n", list[i].tv_sec,
130 list[i].tv_nsec);
131 if (i == inconsistent + 1)
132 ksft_print_msg(msg: "--------------------\n");
133 }
134 delta = list[inconsistent].tv_sec * NSEC_PER_SEC;
135 delta += list[inconsistent].tv_nsec;
136 delta -= list[inconsistent+1].tv_sec * NSEC_PER_SEC;
137 delta -= list[inconsistent+1].tv_nsec;
138 ksft_print_msg(msg: "Delta: %llu ns\n", delta);
139 fflush(0);
140 /* timestamp inconsistency*/
141 t = time(0);
142 ksft_print_msg(msg: "%s\n", ctime(&t));
143 return -1;
144 }
145 now = list[0].tv_sec;
146 }
147 return 0;
148}
149
150
151int main(int argc, char *argv[])
152{
153 int clockid, opt;
154 int userclock = CLOCK_REALTIME;
155 int maxclocks = NR_CLOCKIDS;
156 int runtime = 10;
157 struct timespec ts;
158
159 /* Process arguments */
160 while ((opt = getopt(argc, argv, "t:c:")) != -1) {
161 switch (opt) {
162 case 't':
163 runtime = atoi(optarg);
164 break;
165 case 'c':
166 userclock = atoi(optarg);
167 maxclocks = userclock + 1;
168 break;
169 default:
170 printf("Usage: %s [-t <secs>] [-c <clockid>]\n", argv[0]);
171 printf(" -t: Number of seconds to run\n");
172 printf(" -c: clockid to use (default, all clockids)\n");
173 exit(-1);
174 }
175 }
176
177 setbuf(stdout, NULL);
178
179 ksft_print_header();
180 ksft_set_plan(plan: maxclocks - userclock);
181
182 for (clockid = userclock; clockid < maxclocks; clockid++) {
183
184 if (clockid == CLOCK_HWSPECIFIC || clock_gettime(clockid, &ts)) {
185 ksft_test_result_skip(msg: "%-31s\n", clockstring(clockid));
186 continue;
187 }
188
189 if (consistency_test(clock_type: clockid, seconds: runtime)) {
190 ksft_test_result_fail(msg: "%-31s\n", clockstring(clockid));
191 ksft_exit_fail();
192 } else {
193 ksft_test_result_pass(msg: "%-31s\n", clockstring(clockid));
194 }
195 }
196 ksft_exit_pass();
197}
198

source code of linux/tools/testing/selftests/timers/inconsistency-check.c