1 /* $NetBSD: t_clock_gettime.c,v 1.10 2025/03/25 19:51:32 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 1.10 2025/03/25 19:51:32 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 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" 121 " TSA: 0x%jx.%08jx, TSB: 0x%jx.%08jx, " 122 "diff = %lld nsec, ", (diff < 0) ? "BAD " : "", 123 (uintmax_t)tsa.tv_sec, (uintmax_t)tsa.tv_nsec, 124 (uintmax_t)tsb.tv_sec, (uintmax_t)tsb.tv_nsec, 125 diff); 126 127 elapsed = 1000000000LL * (tsb.tv_sec - tsl.tv_sec) 128 + tsb.tv_nsec - tsl.tv_nsec; 129 130 131 (void)printf("%lld nsec\n", elapsed); 132 tsl = tsb; 133 134 ATF_CHECK(diff >= 0); 135 if (diff < 0) 136 return; 137 } 138 139 tsa.tv_sec = tsb.tv_sec; 140 tsa.tv_nsec = tsb.tv_nsec; 141 } 142 143 if (clock_getres(CLOCK_REALTIME, &res) == 0) { 144 long long r = res.tv_sec * 1000000000 + res.tv_nsec; 145 146 (void)printf("Claimed resolution: %lld nsec (%f Hz) or " 147 "better\n", r, 1.0 / r * 1e9); 148 (void)printf("Observed minimum non zero delta: %lld " 149 "nsec\n", mindiff); 150 } 151 152 #undef CL 153 } 154 155 ATF_TC(clock_gettime_real); 156 ATF_TC_HEAD(clock_gettime_real, tc) 157 { 158 atf_tc_set_md_var(tc, "require.user", "root"); 159 atf_tc_set_md_var(tc, "descr", 160 "Checks the monotonicity of the CLOCK_REALTIME implementation"); 161 atf_tc_set_md_var(tc, "timeout", "300"); 162 } 163 164 ATF_TC_BODY(clock_gettime_real, tc) 165 { 166 char name[128], cbuf[512], ctrbuf[10240]; 167 size_t cbufsiz = sizeof(cbuf); 168 size_t ctrbufsiz = sizeof(ctrbuf); 169 const char *p; 170 char *save; 171 int quality, n; 172 173 if (sysctlbyname(TC_HARDWARE, cbuf, &cbufsiz, NULL, 0) != 0) { 174 (void)printf("\nChecking legacy time implementation " 175 "for %d seconds\n", TIMEOUT); 176 check_timecounter(); 177 return; 178 /* NOTREACHED */ 179 } 180 (void)printf("%s = %s\n", TC_HARDWARE, cbuf); 181 REQUIRE_LIBC(save = strdup(cbuf), NULL); 182 183 RL(sysctlbyname(TC_CHOICE, ctrbuf, &ctrbufsiz, NULL, 0)); 184 (void)printf("%s = %s\n", TC_CHOICE, ctrbuf); 185 186 for (p = ctrbuf, n = 0; sscanf(p, "%127[^(](q=%d, f=%*u Hz)%*[ ]%n", 187 name, &quality, &n) == 2; p += n) { 188 struct timespec ts; 189 int ret; 190 191 if (quality < 0) 192 continue; 193 194 (void)printf("\nChecking %s for %d seconds\n", name, TIMEOUT); 195 CHECK_LIBC(ret = sysctlbyname(TC_HARDWARE, NULL, 0, 196 name, strlen(name)), -1); 197 if (ret == -1) 198 continue; 199 200 /* wait a bit to select new counter in clockinterrupt */ 201 ts.tv_sec = 0; 202 ts.tv_nsec = 100000000; 203 (void)nanosleep(&ts, NULL); 204 205 check_timecounter(); 206 } 207 208 RL(sysctlbyname(TC_HARDWARE, NULL, 0, save, strlen(save))); 209 } 210 211 static void 212 waste_user_time(void) 213 { 214 static char buf[4*4096]; 215 216 arc4random_buf(buf, sizeof(buf)); 217 } 218 219 static void __unused 220 waste_system_time(void) 221 { 222 static char buf[4*4096]; 223 int fd[2]; 224 int i, n; 225 226 RL(pipe2(fd, O_NONBLOCK)); 227 RL(n = ioctl(fd[1], FIONSPACE)); 228 n = MIN((unsigned)MAX(0, n), sizeof(buf)); 229 for (i = 0; i < 16; i++) { 230 RL(write(fd[1], buf, n)); 231 RL(read(fd[0], buf, n)); 232 } 233 RL(close(fd[0])); 234 RL(close(fd[1])); 235 } 236 237 static void 238 check_monotonicity(const char *clockname, clockid_t clockid, 239 void (*waste_time)(void)) 240 { 241 static const struct timespec maxtime = {5, 0}; 242 struct timespec mono_t0, t0, mono_d; 243 244 RL(clock_gettime(CLOCK_MONOTONIC, &mono_t0)); 245 RL(clock_gettime(clockid, &t0)); 246 247 do { 248 struct timespec t1, mono_t1; 249 250 (*waste_time)(); 251 252 RL(clock_gettime(clockid, &t1)); 253 ATF_CHECK_MSG(timespeccmp(&t0, &t1, <=), 254 "clock %s=0x%jx went backwards t0=%jd.%09ld t1=%jd.%09ld", 255 clockname, (uintmax_t)clockid, 256 (intmax_t)t0.tv_sec, t0.tv_nsec, 257 (intmax_t)t1.tv_sec, t1.tv_nsec); 258 259 t0 = t1; 260 261 RL(clock_gettime(CLOCK_MONOTONIC, &mono_t1)); 262 timespecsub(&mono_t1, &mono_t0, &mono_d); 263 } while (timespeccmp(&mono_d, &maxtime, <)); 264 } 265 266 ATF_TC(clock_gettime_process_cputime_is_monotonic); 267 ATF_TC_HEAD(clock_gettime_process_cputime_is_monotonic, tc) 268 { 269 atf_tc_set_md_var(tc, "descr", 270 "Checks that CLOCK_PROCESS_CPUTIME_ID is monotonic"); 271 } 272 ATF_TC_BODY(clock_gettime_process_cputime_is_monotonic, tc) 273 { 274 check_monotonicity("CLOCK_PROCESS_CPUTIME_ID", 275 CLOCK_PROCESS_CPUTIME_ID, &waste_user_time); 276 } 277 278 ATF_TC(clock_gettime_thread_cputime_is_monotonic); 279 ATF_TC_HEAD(clock_gettime_thread_cputime_is_monotonic, tc) 280 { 281 atf_tc_set_md_var(tc, "descr", 282 "Checks that CLOCK_THREAD_CPUTIME_ID is monotonic"); 283 } 284 ATF_TC_BODY(clock_gettime_thread_cputime_is_monotonic, tc) 285 { 286 check_monotonicity("CLOCK_THREAD_CPUTIME_ID", 287 CLOCK_THREAD_CPUTIME_ID, &waste_user_time); 288 } 289 290 static void 291 check_resolution(const char *clockname, clockid_t clockid) 292 { 293 struct timespec ts; 294 int rv; 295 296 RLF(rv = clock_getres(clockid, &ts), "%s", clockname); 297 if (rv != -1) { 298 ATF_CHECK_MSG(ts.tv_sec == 0, 299 "The resolution of the clock %s is reported as %jd.%09ld" 300 " which is lower than a second; most likely a wrong value", 301 clockname, ts.tv_sec, ts.tv_nsec); 302 } 303 } 304 305 ATF_TC(clock_getres); 306 ATF_TC_HEAD(clock_getres, tc) 307 { 308 atf_tc_set_md_var(tc, "descr", 309 "Checks that clock_getres(2) returns some reasonable resolution" 310 " for all supported clocks"); 311 } 312 ATF_TC_BODY(clock_getres, tc) 313 { 314 check_resolution("CLOCK_REALTIME", CLOCK_REALTIME); 315 check_resolution("CLOCK_MONOTONIC", CLOCK_MONOTONIC); 316 atf_tc_expect_fail("These clocks aren't supported but are documented" 317 " in clock_gettime(2) for some reason"); 318 check_resolution("CLOCK_VIRTUAL", CLOCK_VIRTUAL); 319 check_resolution("CLOCK_PROF", CLOCK_PROF); 320 atf_tc_expect_pass(); 321 check_resolution("CLOCK_PROCESS_CPUTIME_ID", CLOCK_PROCESS_CPUTIME_ID); 322 check_resolution("CLOCK_THREAD_CPUTIME_ID", CLOCK_THREAD_CPUTIME_ID); 323 } 324 325 ATF_TP_ADD_TCS(tp) 326 { 327 328 ATF_TP_ADD_TC(tp, clock_gettime_real); 329 ATF_TP_ADD_TC(tp, clock_gettime_process_cputime_is_monotonic); 330 ATF_TP_ADD_TC(tp, clock_gettime_thread_cputime_is_monotonic); 331 ATF_TP_ADD_TC(tp, clock_getres); 332 333 return atf_no_error(); 334 } 335
Indexes created Sat Sep 20 22:09:52 GMT 2025