1 /* $NetBSD: t_clock_gettime.c,v 1.6 2023/07/09 19:19:40 riastradh Exp $ */
2
3 /*-
4 * Copyright (c) 2008 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Frank Kardel.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29 * POSSIBILITY OF SUCH DAMAGE.
30 */
31
32 /*-
33 * Copyright (c) 2006 Frank Kardel
34 * All rights reserved.
35 *
36 * Redistribution and use in source and binary forms, with or without
37 * modification, are permitted provided that the following conditions
38 * are met:
39 * 1. Redistributions of source code must retain the above copyright
40 * notice, this list of conditions and the following disclaimer.
41 * 2. Redistributions in binary form must reproduce the above copyright
42 * notice, this list of conditions and the following disclaimer in the
43 * documentation and/or other materials provided with the distribution.
44 *
45 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
46 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
47 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
48 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
49 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
50 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
51 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
52 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
53 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
54 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
55 * POSSIBILITY OF SUCH DAMAGE.
56 */
57
58 #include <sys/cdefs.h>
59 __COPYRIGHT("@(#) Copyright (c) 2008\
60 The NetBSD Foundation, inc. All rights reserved.");
61 __RCSID("$NetBSD: t_clock_gettime.c,v 1.6 2023/07/09 19:19:40 riastradh Exp $");
62
63 #include <sys/param.h>
64
65 #include <sys/ioctl.h>
66 #include <sys/sysctl.h>
67
68 #include <atf-c.h>
69 #include <errno.h>
70 #include <fcntl.h>
71 #include <limits.h>
72 #include <stdint.h>
73 #include <stdio.h>
74 #include <stdlib.h>
75 #include <string.h>
76 #include <time.h>
77 #include <unistd.h>
78
79 #include "h_macros.h"
80
81 #define MINPOSDIFF 15000000 /* 15 ms for now */
82 #define TIMEOUT 5
83
84 #define TC_HARDWARE "kern.timecounter.hardware"
85 #define TC_CHOICE "kern.timecounter.choice"
86
87 static void
check_timecounter(void)88 check_timecounter(void)
89 {
90 struct timespec tsa, tsb, tsl, res;
91 long long mindiff = INTMAX_MAX;
92 time_t endlimit;
93
94 #define CL(x) \
95 do { \
96 if ((x) != -1) \
97 break; \
98 atf_tc_fail_nonfatal("%s: %s", #x, strerror(errno)); \
99 return; \
100 } while (0)
101
102 CL(clock_gettime(CLOCK_REALTIME, &tsa));
103 tsl = tsa;
104
105 CL(time(&endlimit));
106 endlimit += TIMEOUT + 1;
107
108 while ((time_t)tsa.tv_sec < endlimit) {
109 long long diff;
110
111 CL(clock_gettime(CLOCK_REALTIME, &tsb));
112 diff = 1000000000LL * (tsb.tv_sec - tsa.tv_sec)
113 + tsb.tv_nsec - tsa.tv_nsec;
114
115 if (diff > 0 && mindiff > diff)
116 mindiff = diff;
117
118 if (diff < 0 || diff > MINPOSDIFF) {
119 long long elapsed;
120 (void)printf("%stime TSA: 0x%jx.%08jx, TSB: 0x%jx.%08jx, "
121 "diff = %lld nsec, ", (diff < 0) ? "BAD " : "",
122 (uintmax_t)tsa.tv_sec, (uintmax_t)tsa.tv_nsec,
123 (uintmax_t)tsb.tv_sec, (uintmax_t)tsb.tv_nsec, diff);
124
125 elapsed = 1000000000LL * (tsb.tv_sec - tsl.tv_sec)
126 + tsb.tv_nsec - tsl.tv_nsec;
127
128
129 (void)printf("%lld nsec\n", elapsed);
130 tsl = tsb;
131
132 ATF_CHECK(diff >= 0);
133 if (diff < 0)
134 return;
135 }
136
137 tsa.tv_sec = tsb.tv_sec;
138 tsa.tv_nsec = tsb.tv_nsec;
139 }
140
141 if (clock_getres(CLOCK_REALTIME, &res) == 0) {
142 long long r = res.tv_sec * 1000000000 + res.tv_nsec;
143
144 (void)printf("Claimed resolution: %lld nsec (%f Hz) or "
145 "better\n", r, 1.0 / r * 1e9);
146 (void)printf("Observed minimum non zero delta: %lld "
147 "nsec\n", mindiff);
148 }
149
150 #undef CL
151 }
152
153 ATF_TC(clock_gettime_real);
ATF_TC_HEAD(clock_gettime_real,tc)154 ATF_TC_HEAD(clock_gettime_real, tc)
155 {
156 atf_tc_set_md_var(tc, "require.user", "root");
157 atf_tc_set_md_var(tc, "descr",
158 "Checks the monotonicity of the CLOCK_REALTIME implementation");
159 atf_tc_set_md_var(tc, "timeout", "300");
160 }
161
ATF_TC_BODY(clock_gettime_real,tc)162 ATF_TC_BODY(clock_gettime_real, tc)
163 {
164 char name[128], cbuf[512], ctrbuf[10240];
165 size_t cbufsiz = sizeof(cbuf);
166 size_t ctrbufsiz = sizeof(ctrbuf);
167 const char *p;
168 char *save;
169 int quality, n;
170
171 if (sysctlbyname(TC_HARDWARE, cbuf, &cbufsiz, NULL, 0) != 0) {
172 (void)printf("\nChecking legacy time implementation "
173 "for %d seconds\n", TIMEOUT);
174 check_timecounter();
175 return;
176 /* NOTREACHED */
177 }
178 (void)printf("%s = %s\n", TC_HARDWARE, cbuf);
179 REQUIRE_LIBC(save = strdup(cbuf), NULL);
180
181 RL(sysctlbyname(TC_CHOICE, ctrbuf, &ctrbufsiz, NULL, 0));
182 (void)printf("%s = %s\n", TC_CHOICE, ctrbuf);
183
184 for (p = ctrbuf, n = 0; sscanf(p, "%127[^(](q=%d, f=%*u Hz)%*[ ]%n",
185 name, &quality, &n) == 2; p += n) {
186 struct timespec ts;
187 int ret;
188
189 if (quality < 0)
190 continue;
191
192 (void)printf("\nChecking %s for %d seconds\n", name, TIMEOUT);
193 CHECK_LIBC(ret = sysctlbyname(TC_HARDWARE, NULL, 0,
194 name, strlen(name)), -1);
195 if (ret == -1)
196 continue;
197
198 /* wait a bit to select new counter in clockinterrupt */
199 ts.tv_sec = 0;
200 ts.tv_nsec = 100000000;
201 (void)nanosleep(&ts, NULL);
202
203 check_timecounter();
204 }
205
206 RL(sysctlbyname(TC_HARDWARE, NULL, 0, save, strlen(save)));
207 }
208
209 static void
waste_user_time(void)210 waste_user_time(void)
211 {
212 static char buf[4*4096];
213
214 arc4random_buf(buf, sizeof(buf));
215 }
216
217 static void __unused
waste_system_time(void)218 waste_system_time(void)
219 {
220 static char buf[4*4096];
221 int fd[2];
222 int i, n;
223
224 RL(pipe2(fd, O_NONBLOCK));
225 RL(n = ioctl(fd[1], FIONSPACE));
226 n = MIN((unsigned)MAX(0, n), sizeof(buf));
227 for (i = 0; i < 16; i++) {
228 RL(write(fd[1], buf, n));
229 RL(read(fd[0], buf, n));
230 }
231 RL(close(fd[0]));
232 RL(close(fd[1]));
233 }
234
235 static void
check_monotonicity(const char * clockname,clockid_t clockid,void (* waste_time)(void))236 check_monotonicity(const char *clockname, clockid_t clockid,
237 void (*waste_time)(void))
238 {
239 static const struct timespec maxtime = {5, 0};
240 struct timespec mono_t0, t0, mono_d;
241
242 RL(clock_gettime(CLOCK_MONOTONIC, &mono_t0));
243 RL(clock_gettime(clockid, &t0));
244
245 do {
246 struct timespec t1, mono_t1;
247
248 (*waste_time)();
249
250 RL(clock_gettime(clockid, &t1));
251 ATF_CHECK_MSG(timespeccmp(&t0, &t1, <=),
252 "clock %s=0x%jx went backwards t0=%jd.%09ld t1=%jd.%09ld",
253 clockname, (uintmax_t)clockid,
254 (intmax_t)t0.tv_sec, t0.tv_nsec,
255 (intmax_t)t1.tv_sec, t1.tv_nsec);
256
257 t0 = t1;
258
259 RL(clock_gettime(CLOCK_MONOTONIC, &mono_t1));
260 timespecsub(&mono_t1, &mono_t0, &mono_d);
261 } while (timespeccmp(&mono_d, &maxtime, <));
262 }
263
264 ATF_TC(clock_gettime_process_cputime_is_monotonic);
ATF_TC_HEAD(clock_gettime_process_cputime_is_monotonic,tc)265 ATF_TC_HEAD(clock_gettime_process_cputime_is_monotonic, tc)
266 {
267 atf_tc_set_md_var(tc, "descr",
268 "Checks that CLOCK_PROCESS_CPUTIME_ID is monotonic");
269 }
ATF_TC_BODY(clock_gettime_process_cputime_is_monotonic,tc)270 ATF_TC_BODY(clock_gettime_process_cputime_is_monotonic, tc)
271 {
272 check_monotonicity("CLOCK_PROCESS_CPUTIME_ID",
273 CLOCK_PROCESS_CPUTIME_ID, &waste_user_time);
274 }
275
276 ATF_TC(clock_gettime_thread_cputime_is_monotonic);
ATF_TC_HEAD(clock_gettime_thread_cputime_is_monotonic,tc)277 ATF_TC_HEAD(clock_gettime_thread_cputime_is_monotonic, tc)
278 {
279 atf_tc_set_md_var(tc, "descr",
280 "Checks that CLOCK_THREAD_CPUTIME_ID is monotonic");
281 }
ATF_TC_BODY(clock_gettime_thread_cputime_is_monotonic,tc)282 ATF_TC_BODY(clock_gettime_thread_cputime_is_monotonic, tc)
283 {
284 check_monotonicity("CLOCK_THREAD_CPUTIME_ID",
285 CLOCK_THREAD_CPUTIME_ID, &waste_user_time);
286 }
287
ATF_TP_ADD_TCS(tp)288 ATF_TP_ADD_TCS(tp)
289 {
290
291 ATF_TP_ADD_TC(tp, clock_gettime_real);
292 ATF_TP_ADD_TC(tp, clock_gettime_process_cputime_is_monotonic);
293 ATF_TP_ADD_TC(tp, clock_gettime_thread_cputime_is_monotonic);
294
295 return atf_no_error();
296 }
297