subr_time.c revision 1.20.8.1
1 /* $NetBSD: subr_time.c,v 1.20.8.1 2024/10/11 17:18:05 martin Exp $ */ 2 3 /* 4 * Copyright (c) 1982, 1986, 1989, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. Neither the name of the University nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 * 31 * @(#)kern_clock.c 8.5 (Berkeley) 1/21/94 32 * @(#)kern_time.c 8.4 (Berkeley) 5/26/95 33 */ 34 35 #include <sys/cdefs.h> 36 __KERNEL_RCSID(0, "$NetBSD: subr_time.c,v 1.20.8.1 2024/10/11 17:18:05 martin Exp $"); 37 38 #include <sys/param.h> 39 #include <sys/kernel.h> 40 #include <sys/proc.h> 41 #include <sys/kauth.h> 42 #include <sys/lwp.h> 43 #include <sys/timex.h> 44 #include <sys/time.h> 45 #include <sys/timetc.h> 46 #include <sys/intr.h> 47 48 /* 49 * Compute number of hz until specified time. Used to compute second 50 * argument to callout_reset() from an absolute time. 51 */ 52 int 53 tvhzto(const struct timeval *tvp) 54 { 55 struct timeval now, tv; 56 57 tv = *tvp; /* Don't modify original tvp. */ 58 getmicrotime(&now); 59 timersub(&tv, &now, &tv); 60 return tvtohz(&tv); 61 } 62 63 /* 64 * Compute number of ticks in the specified amount of time. 65 */ 66 int 67 tvtohz(const struct timeval *tv) 68 { 69 unsigned long ticks; 70 long sec, usec; 71 72 /* 73 * If the number of usecs in the whole seconds part of the time 74 * difference fits in a long, then the total number of usecs will 75 * fit in an unsigned long. Compute the total and convert it to 76 * ticks, rounding up and adding 1 to allow for the current tick 77 * to expire. Rounding also depends on unsigned long arithmetic 78 * to avoid overflow. 79 * 80 * Otherwise, if the number of ticks in the whole seconds part of 81 * the time difference fits in a long, then convert the parts to 82 * ticks separately and add, using similar rounding methods and 83 * overflow avoidance. This method would work in the previous 84 * case, but it is slightly slower and assumes that hz is integral. 85 * 86 * Otherwise, round the time difference down to the maximum 87 * representable value. 88 * 89 * If ints are 32-bit, then the maximum value for any timeout in 90 * 10ms ticks is 248 days. 91 */ 92 sec = tv->tv_sec; 93 usec = tv->tv_usec; 94 95 KASSERT(usec >= 0); 96 KASSERT(usec < 1000000); 97 98 /* catch overflows in conversion time_t->int */ 99 if (tv->tv_sec > INT_MAX) 100 return INT_MAX; 101 if (tv->tv_sec < 0) 102 return 0; 103 104 if (sec < 0 || (sec == 0 && usec == 0)) { 105 /* 106 * Would expire now or in the past. Return 0 ticks. 107 * This is different from the legacy tvhzto() interface, 108 * and callers need to check for it. 109 */ 110 ticks = 0; 111 } else if (sec <= (LONG_MAX / 1000000)) 112 ticks = (((sec * 1000000) + (unsigned long)usec + (tick - 1)) 113 / tick) + 1; 114 else if (sec <= (LONG_MAX / hz)) 115 ticks = (sec * hz) + 116 (((unsigned long)usec + (tick - 1)) / tick) + 1; 117 else 118 ticks = LONG_MAX; 119 120 if (ticks > INT_MAX) 121 ticks = INT_MAX; 122 123 return ((int)ticks); 124 } 125 126 int 127 tshzto(const struct timespec *tsp) 128 { 129 struct timespec now, ts; 130 131 ts = *tsp; /* Don't modify original tsp. */ 132 getnanotime(&now); 133 timespecsub(&ts, &now, &ts); 134 return tstohz(&ts); 135 } 136 137 int 138 tshztoup(const struct timespec *tsp) 139 { 140 struct timespec now, ts; 141 142 ts = *tsp; /* Don't modify original tsp. */ 143 getnanouptime(&now); 144 timespecsub(&ts, &now, &ts); 145 return tstohz(&ts); 146 } 147 148 /* 149 * Compute number of ticks in the specified amount of time. 150 */ 151 int 152 tstohz(const struct timespec *ts) 153 { 154 struct timeval tv; 155 156 /* 157 * usec has great enough resolution for hz, so convert to a 158 * timeval and use tvtohz() above. 159 */ 160 TIMESPEC_TO_TIMEVAL(&tv, ts); 161 return tvtohz(&tv); 162 } 163 164 /* 165 * Check that a proposed value to load into the .it_value or 166 * .it_interval part of an interval timer is acceptable, and 167 * fix it to have at least minimal value (i.e. if it is less 168 * than the resolution of the clock, round it up.). We don't 169 * timeout the 0,0 value because this means to disable the 170 * timer or the interval. 171 */ 172 int 173 itimerfix(struct timeval *tv) 174 { 175 176 if (tv->tv_usec < 0 || tv->tv_usec >= 1000000) 177 return EINVAL; 178 if (tv->tv_sec < 0) 179 return ETIMEDOUT; 180 if (tv->tv_sec == 0 && tv->tv_usec != 0 && tv->tv_usec < tick) 181 tv->tv_usec = tick; 182 return 0; 183 } 184 185 int 186 itimespecfix(struct timespec *ts) 187 { 188 189 if (ts->tv_nsec < 0 || ts->tv_nsec >= 1000000000) 190 return EINVAL; 191 if (ts->tv_sec < 0) 192 return ETIMEDOUT; 193 if (ts->tv_sec == 0 && ts->tv_nsec != 0 && ts->tv_nsec < tick * 1000) 194 ts->tv_nsec = tick * 1000; 195 return 0; 196 } 197 198 int 199 inittimeleft(struct timespec *ts, struct timespec *sleepts) 200 { 201 202 if (itimespecfix(ts)) { 203 return -1; 204 } 205 getnanouptime(sleepts); 206 return 0; 207 } 208 209 int 210 gettimeleft(struct timespec *ts, struct timespec *sleepts) 211 { 212 struct timespec sleptts; 213 214 /* 215 * Reduce ts by elapsed time based on monotonic time scale. 216 */ 217 getnanouptime(&sleptts); 218 timespecadd(ts, sleepts, ts); 219 timespecsub(ts, &sleptts, ts); 220 *sleepts = sleptts; 221 222 return tstohz(ts); 223 } 224 225 void 226 clock_timeleft(clockid_t clockid, struct timespec *ts, struct timespec *sleepts) 227 { 228 struct timespec sleptts; 229 230 clock_gettime1(clockid, &sleptts); 231 timespecadd(ts, sleepts, ts); 232 timespecsub(ts, &sleptts, ts); 233 *sleepts = sleptts; 234 } 235 236 int 237 clock_gettime1(clockid_t clock_id, struct timespec *ts) 238 { 239 int error; 240 struct proc *p; 241 242 #define CPUCLOCK_ID_MASK (~(CLOCK_THREAD_CPUTIME_ID|CLOCK_PROCESS_CPUTIME_ID)) 243 if (clock_id & CLOCK_PROCESS_CPUTIME_ID) { 244 pid_t pid = clock_id & CPUCLOCK_ID_MASK; 245 struct timeval cputime; 246 247 mutex_enter(proc_lock); 248 p = pid == 0 ? curproc : proc_find(pid); 249 if (p == NULL) { 250 mutex_exit(proc_lock); 251 return ESRCH; 252 } 253 mutex_enter(p->p_lock); 254 calcru(p, /*usertime*/NULL, /*systime*/NULL, /*intrtime*/NULL, 255 &cputime); 256 mutex_exit(p->p_lock); 257 mutex_exit(proc_lock); 258 259 // XXX: Perhaps create a special kauth type 260 error = kauth_authorize_process(curlwp->l_cred, 261 KAUTH_PROCESS_PTRACE, p, 262 KAUTH_ARG(KAUTH_REQ_PROCESS_CANSEE_ENTRY), NULL, NULL); 263 if (error) 264 return error; 265 266 TIMEVAL_TO_TIMESPEC(&cputime, ts); 267 return 0; 268 } else if (clock_id & CLOCK_THREAD_CPUTIME_ID) { 269 struct lwp *l; 270 lwpid_t lid = clock_id & CPUCLOCK_ID_MASK; 271 struct bintime tm = {0, 0}; 272 273 p = curproc; 274 mutex_enter(p->p_lock); 275 l = lid == 0 ? curlwp : lwp_find(p, lid); 276 if (l == NULL) { 277 mutex_exit(p->p_lock); 278 return ESRCH; 279 } 280 addrulwp(l, &tm); 281 mutex_exit(p->p_lock); 282 283 bintime2timespec(&tm, ts); 284 return 0; 285 } 286 287 switch (clock_id) { 288 case CLOCK_REALTIME: 289 nanotime(ts); 290 break; 291 case CLOCK_MONOTONIC: 292 nanouptime(ts); 293 break; 294 default: 295 return EINVAL; 296 } 297 298 return 0; 299 } 300 301 /* 302 * Calculate delta and convert from struct timespec to the ticks. 303 */ 304 int 305 ts2timo(clockid_t clock_id, int flags, struct timespec *ts, 306 int *timo, struct timespec *start) 307 { 308 int error; 309 struct timespec tsd; 310 311 flags &= TIMER_ABSTIME; 312 if (start == NULL) 313 start = &tsd; 314 315 if (flags || start != &tsd) 316 if ((error = clock_gettime1(clock_id, start)) != 0) 317 return error; 318 319 if (flags) 320 timespecsub(ts, start, ts); 321 322 if ((error = itimespecfix(ts)) != 0) 323 return error; 324 325 if (ts->tv_sec == 0 && ts->tv_nsec == 0) 326 return ETIMEDOUT; 327 328 *timo = tstohz(ts); 329 KASSERT(*timo > 0); 330 331 return 0; 332 } 333
Indexes created Mon Sep 29 21:09:56 GMT 2025