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 87static void 88check_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 153ATF_TC(clock_gettime_real); 154ATF_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 162ATF_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 209static void 210waste_user_time(void) 211{ 212 static char buf[4*4096]; 213 214 arc4random_buf(buf, sizeof(buf)); 215} 216 217static void __unused 218waste_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 235static void 236check_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 264ATF_TC(clock_gettime_process_cputime_is_monotonic); 265ATF_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} 270ATF_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 276ATF_TC(clock_gettime_thread_cputime_is_monotonic); 277ATF_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} 282ATF_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 288ATF_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