kern_time.c revision 1.23
1 /* $NetBSD: kern_time.c,v 1.23 1996/11/15 23:53:32 cgd 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. All advertising materials mentioning features or use of this software 16 * must display the following acknowledgement: 17 * This product includes software developed by the University of 18 * California, Berkeley and its contributors. 19 * 4. Neither the name of the University nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 * 35 * @(#)kern_time.c 8.1 (Berkeley) 6/10/93 36 */ 37 38 #include <sys/param.h> 39 #include <sys/resourcevar.h> 40 #include <sys/kernel.h> 41 #include <sys/systm.h> 42 #include <sys/proc.h> 43 #include <sys/vnode.h> 44 #include <sys/signalvar.h> 45 46 #include <sys/mount.h> 47 #include <sys/syscallargs.h> 48 49 #if defined(NFSCLIENT) || defined(NFSSERVER) 50 #include <nfs/rpcv2.h> 51 #include <nfs/nfsproto.h> 52 #include <nfs/nfs_var.h> 53 #endif 54 55 #include <machine/cpu.h> 56 57 static void settime __P((struct timeval *)); 58 59 /* 60 * Time of day and interval timer support. 61 * 62 * These routines provide the kernel entry points to get and set 63 * the time-of-day and per-process interval timers. Subroutines 64 * here provide support for adding and subtracting timeval structures 65 * and decrementing interval timers, optionally reloading the interval 66 * timers when they expire. 67 */ 68 69 70 /* This function is used by clock_settime and settimeofday */ 71 static void 72 settime(tv) 73 struct timeval *tv; 74 { 75 struct timeval delta; 76 int s; 77 78 /* WHAT DO WE DO ABOUT PENDING REAL-TIME TIMEOUTS??? */ 79 s = splclock(); 80 timersub(tv, &time, &delta); 81 time = *tv; 82 (void) splsoftclock(); 83 timeradd(&boottime, &delta, &boottime); 84 timeradd(&runtime, &delta, &runtime); 85 # if defined(NFSCLIENT) || defined(NFSSERVER) 86 nqnfs_lease_updatetime(delta.tv_sec); 87 # endif 88 splx(s); 89 resettodr(); 90 } 91 92 /* ARGSUSED */ 93 int 94 sys_clock_gettime(p, v, retval) 95 struct proc *p; 96 void *v; 97 register_t *retval; 98 { 99 register struct sys_clock_gettime_args /* { 100 syscallarg(clockid_t) clock_id; 101 syscallarg(struct timespec *) tp; 102 } */ *uap = v; 103 clockid_t clock_id; 104 struct timeval atv; 105 struct timespec ats; 106 107 clock_id = SCARG(uap, clock_id); 108 if (clock_id != CLOCK_REALTIME) 109 return (EINVAL); 110 111 microtime(&atv); 112 TIMEVAL_TO_TIMESPEC(&atv,&ats); 113 114 return copyout((caddr_t)&ats, SCARG(uap, tp), sizeof(ats)); 115 } 116 117 /* ARGSUSED */ 118 int 119 sys_clock_settime(p, v, retval) 120 struct proc *p; 121 void *v; 122 register_t *retval; 123 { 124 register struct sys_clock_settime_args /* { 125 syscallarg(clockid_t) clock_id; 126 syscallarg(const struct timespec *) tp; 127 } */ *uap = v; 128 clockid_t clock_id; 129 struct timeval atv; 130 struct timespec ats; 131 int error; 132 133 if ((error = suser(p->p_ucred, &p->p_acflag)) != 0) 134 return (error); 135 136 clock_id = SCARG(uap, clock_id); 137 if (clock_id != CLOCK_REALTIME) 138 return (EINVAL); 139 140 if ((error = copyin((const char *)SCARG(uap, tp), (caddr_t)&ats, 141 sizeof(ats))) != 0) 142 return (error); 143 144 TIMESPEC_TO_TIMEVAL(&atv,&ats); 145 settime(&atv); 146 147 return 0; 148 } 149 150 int 151 sys_clock_getres(p, v, retval) 152 struct proc *p; 153 void *v; 154 register_t *retval; 155 { 156 register struct sys_clock_getres_args /* { 157 syscallarg(clockid_t) clock_id; 158 syscallarg(struct timespec *) tp; 159 } */ *uap = v; 160 clockid_t clock_id; 161 struct timespec ts; 162 int error = 0; 163 164 clock_id = SCARG(uap, clock_id); 165 if (clock_id != CLOCK_REALTIME) 166 return (EINVAL); 167 168 if (SCARG(uap, tp)) { 169 ts.tv_sec = 0; 170 ts.tv_nsec = 1000000000 / hz; 171 172 error = copyout((caddr_t)&ts, (caddr_t)SCARG(uap, tp), 173 sizeof (ts)); 174 } 175 176 return error; 177 } 178 179 180 /* ARGSUSED */ 181 int 182 sys_gettimeofday(p, v, retval) 183 struct proc *p; 184 void *v; 185 register_t *retval; 186 { 187 register struct sys_gettimeofday_args /* { 188 syscallarg(struct timeval *) tp; 189 syscallarg(struct timezone *) tzp; 190 } */ *uap = v; 191 struct timeval atv; 192 int error = 0; 193 194 if (SCARG(uap, tp)) { 195 microtime(&atv); 196 error = copyout((caddr_t)&atv, (caddr_t)SCARG(uap, tp), 197 sizeof (atv)); 198 if (error) 199 return (error); 200 } 201 if (SCARG(uap, tzp)) 202 error = copyout((caddr_t)&tz, (caddr_t)SCARG(uap, tzp), 203 sizeof (tz)); 204 return (error); 205 } 206 207 /* ARGSUSED */ 208 int 209 sys_settimeofday(p, v, retval) 210 struct proc *p; 211 void *v; 212 register_t *retval; 213 { 214 struct sys_settimeofday_args /* { 215 syscallarg(struct timeval *) tv; 216 syscallarg(struct timezone *) tzp; 217 } */ *uap = v; 218 struct timeval atv; 219 struct timezone atz; 220 int error; 221 222 if ((error = suser(p->p_ucred, &p->p_acflag)) != 0) 223 return (error); 224 /* Verify all parameters before changing time. */ 225 if (SCARG(uap, tv) && (error = copyin((caddr_t)SCARG(uap, tv), 226 (caddr_t)&atv, sizeof(atv)))) 227 return (error); 228 if (SCARG(uap, tzp) && (error = copyin((caddr_t)SCARG(uap, tzp), 229 (caddr_t)&atz, sizeof(atz)))) 230 return (error); 231 if (SCARG(uap, tv)) 232 settime(&atv); 233 if (SCARG(uap, tzp)) 234 tz = atz; 235 return (0); 236 } 237 238 int tickdelta; /* current clock skew, us. per tick */ 239 long timedelta; /* unapplied time correction, us. */ 240 long bigadj = 1000000; /* use 10x skew above bigadj us. */ 241 242 /* ARGSUSED */ 243 int 244 sys_adjtime(p, v, retval) 245 struct proc *p; 246 void *v; 247 register_t *retval; 248 { 249 register struct sys_adjtime_args /* { 250 syscallarg(struct timeval *) delta; 251 syscallarg(struct timeval *) olddelta; 252 } */ *uap = v; 253 struct timeval atv; 254 register long ndelta, ntickdelta, odelta; 255 int s, error; 256 257 if ((error = suser(p->p_ucred, &p->p_acflag)) != 0) 258 return (error); 259 260 error = copyin((caddr_t)SCARG(uap, delta), (caddr_t)&atv, 261 sizeof(struct timeval)); 262 if (error) 263 return (error); 264 265 /* 266 * Compute the total correction and the rate at which to apply it. 267 * Round the adjustment down to a whole multiple of the per-tick 268 * delta, so that after some number of incremental changes in 269 * hardclock(), tickdelta will become zero, lest the correction 270 * overshoot and start taking us away from the desired final time. 271 */ 272 ndelta = atv.tv_sec * 1000000 + atv.tv_usec; 273 if (ndelta > bigadj) 274 ntickdelta = 10 * tickadj; 275 else 276 ntickdelta = tickadj; 277 if (ndelta % ntickdelta) 278 ndelta = ndelta / ntickdelta * ntickdelta; 279 280 /* 281 * To make hardclock()'s job easier, make the per-tick delta negative 282 * if we want time to run slower; then hardclock can simply compute 283 * tick + tickdelta, and subtract tickdelta from timedelta. 284 */ 285 if (ndelta < 0) 286 ntickdelta = -ntickdelta; 287 s = splclock(); 288 odelta = timedelta; 289 timedelta = ndelta; 290 tickdelta = ntickdelta; 291 splx(s); 292 293 if (SCARG(uap, olddelta)) { 294 atv.tv_sec = odelta / 1000000; 295 atv.tv_usec = odelta % 1000000; 296 (void) copyout((caddr_t)&atv, (caddr_t)SCARG(uap, olddelta), 297 sizeof(struct timeval)); 298 } 299 return (0); 300 } 301 302 /* 303 * Get value of an interval timer. The process virtual and 304 * profiling virtual time timers are kept in the p_stats area, since 305 * they can be swapped out. These are kept internally in the 306 * way they are specified externally: in time until they expire. 307 * 308 * The real time interval timer is kept in the process table slot 309 * for the process, and its value (it_value) is kept as an 310 * absolute time rather than as a delta, so that it is easy to keep 311 * periodic real-time signals from drifting. 312 * 313 * Virtual time timers are processed in the hardclock() routine of 314 * kern_clock.c. The real time timer is processed by a timeout 315 * routine, called from the softclock() routine. Since a callout 316 * may be delayed in real time due to interrupt processing in the system, 317 * it is possible for the real time timeout routine (realitexpire, given below), 318 * to be delayed in real time past when it is supposed to occur. It 319 * does not suffice, therefore, to reload the real timer .it_value from the 320 * real time timers .it_interval. Rather, we compute the next time in 321 * absolute time the timer should go off. 322 */ 323 /* ARGSUSED */ 324 int 325 sys_getitimer(p, v, retval) 326 struct proc *p; 327 void *v; 328 register_t *retval; 329 { 330 register struct sys_getitimer_args /* { 331 syscallarg(u_int) which; 332 syscallarg(struct itimerval *) itv; 333 } */ *uap = v; 334 struct itimerval aitv; 335 int s; 336 337 if (SCARG(uap, which) > ITIMER_PROF) 338 return (EINVAL); 339 s = splclock(); 340 if (SCARG(uap, which) == ITIMER_REAL) { 341 /* 342 * Convert from absolute to relative time in .it_value 343 * part of real time timer. If time for real time timer 344 * has passed return 0, else return difference between 345 * current time and time for the timer to go off. 346 */ 347 aitv = p->p_realtimer; 348 if (timerisset(&aitv.it_value)) 349 if (timercmp(&aitv.it_value, &time, <)) 350 timerclear(&aitv.it_value); 351 else 352 timersub(&aitv.it_value, &time, &aitv.it_value); 353 } else 354 aitv = p->p_stats->p_timer[SCARG(uap, which)]; 355 splx(s); 356 return (copyout((caddr_t)&aitv, (caddr_t)SCARG(uap, itv), 357 sizeof (struct itimerval))); 358 } 359 360 /* ARGSUSED */ 361 int 362 sys_setitimer(p, v, retval) 363 struct proc *p; 364 register void *v; 365 register_t *retval; 366 { 367 register struct sys_setitimer_args /* { 368 syscallarg(u_int) which; 369 syscallarg(struct itimerval *) itv; 370 syscallarg(struct itimerval *) oitv; 371 } */ *uap = v; 372 struct sys_getitimer_args getargs; 373 struct itimerval aitv; 374 register struct itimerval *itvp; 375 int s, error; 376 377 if (SCARG(uap, which) > ITIMER_PROF) 378 return (EINVAL); 379 itvp = SCARG(uap, itv); 380 if (itvp && (error = copyin((caddr_t)itvp, (caddr_t)&aitv, 381 sizeof(struct itimerval)))) 382 return (error); 383 if (SCARG(uap, oitv) != NULL) { 384 SCARG(&getargs, which) = SCARG(uap, which); 385 SCARG(&getargs, itv) = SCARG(uap, oitv); 386 if ((error = sys_getitimer(p, &getargs, retval)) != 0) 387 return (error); 388 } 389 if (itvp == 0) 390 return (0); 391 if (itimerfix(&aitv.it_value) || itimerfix(&aitv.it_interval)) 392 return (EINVAL); 393 s = splclock(); 394 if (SCARG(uap, which) == ITIMER_REAL) { 395 untimeout(realitexpire, p); 396 if (timerisset(&aitv.it_value)) { 397 timeradd(&aitv.it_value, &time, &aitv.it_value); 398 timeout(realitexpire, p, hzto(&aitv.it_value)); 399 } 400 p->p_realtimer = aitv; 401 } else 402 p->p_stats->p_timer[SCARG(uap, which)] = aitv; 403 splx(s); 404 return (0); 405 } 406 407 /* 408 * Real interval timer expired: 409 * send process whose timer expired an alarm signal. 410 * If time is not set up to reload, then just return. 411 * Else compute next time timer should go off which is > current time. 412 * This is where delay in processing this timeout causes multiple 413 * SIGALRM calls to be compressed into one. 414 */ 415 void 416 realitexpire(arg) 417 void *arg; 418 { 419 register struct proc *p; 420 int s; 421 422 p = (struct proc *)arg; 423 psignal(p, SIGALRM); 424 if (!timerisset(&p->p_realtimer.it_interval)) { 425 timerclear(&p->p_realtimer.it_value); 426 return; 427 } 428 for (;;) { 429 s = splclock(); 430 timeradd(&p->p_realtimer.it_value, 431 &p->p_realtimer.it_interval, &p->p_realtimer.it_value); 432 if (timercmp(&p->p_realtimer.it_value, &time, >)) { 433 timeout(realitexpire, p, 434 hzto(&p->p_realtimer.it_value)); 435 splx(s); 436 return; 437 } 438 splx(s); 439 } 440 } 441 442 /* 443 * Check that a proposed value to load into the .it_value or 444 * .it_interval part of an interval timer is acceptable, and 445 * fix it to have at least minimal value (i.e. if it is less 446 * than the resolution of the clock, round it up.) 447 */ 448 int 449 itimerfix(tv) 450 struct timeval *tv; 451 { 452 453 if (tv->tv_sec < 0 || tv->tv_sec > 100000000 || 454 tv->tv_usec < 0 || tv->tv_usec >= 1000000) 455 return (EINVAL); 456 if (tv->tv_sec == 0 && tv->tv_usec != 0 && tv->tv_usec < tick) 457 tv->tv_usec = tick; 458 return (0); 459 } 460 461 /* 462 * Decrement an interval timer by a specified number 463 * of microseconds, which must be less than a second, 464 * i.e. < 1000000. If the timer expires, then reload 465 * it. In this case, carry over (usec - old value) to 466 * reduce the value reloaded into the timer so that 467 * the timer does not drift. This routine assumes 468 * that it is called in a context where the timers 469 * on which it is operating cannot change in value. 470 */ 471 int 472 itimerdecr(itp, usec) 473 register struct itimerval *itp; 474 int usec; 475 { 476 477 if (itp->it_value.tv_usec < usec) { 478 if (itp->it_value.tv_sec == 0) { 479 /* expired, and already in next interval */ 480 usec -= itp->it_value.tv_usec; 481 goto expire; 482 } 483 itp->it_value.tv_usec += 1000000; 484 itp->it_value.tv_sec--; 485 } 486 itp->it_value.tv_usec -= usec; 487 usec = 0; 488 if (timerisset(&itp->it_value)) 489 return (1); 490 /* expired, exactly at end of interval */ 491 expire: 492 if (timerisset(&itp->it_interval)) { 493 itp->it_value = itp->it_interval; 494 itp->it_value.tv_usec -= usec; 495 if (itp->it_value.tv_usec < 0) { 496 itp->it_value.tv_usec += 1000000; 497 itp->it_value.tv_sec--; 498 } 499 } else 500 itp->it_value.tv_usec = 0; /* sec is already 0 */ 501 return (0); 502 } 503
Indexes created Thu Sep 25 02:09:54 GMT 2025