kern_time.c revision 1.54.2.2
1 /* $NetBSD: kern_time.c,v 1.54.2.2 2001/06/21 20:06:57 nathanw Exp $ */ 2 3 /*- 4 * Copyright (c) 2000 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Christopher G. Demetriou. 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 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the NetBSD 21 * Foundation, Inc. and its contributors. 22 * 4. Neither the name of The NetBSD Foundation nor the names of its 23 * contributors may be used to endorse or promote products derived 24 * from this software without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 27 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 28 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 29 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 30 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 31 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 32 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 33 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 34 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 35 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 36 * POSSIBILITY OF SUCH DAMAGE. 37 */ 38 39 /* 40 * Copyright (c) 1982, 1986, 1989, 1993 41 * The Regents of the University of California. All rights reserved. 42 * 43 * Redistribution and use in source and binary forms, with or without 44 * modification, are permitted provided that the following conditions 45 * are met: 46 * 1. Redistributions of source code must retain the above copyright 47 * notice, this list of conditions and the following disclaimer. 48 * 2. Redistributions in binary form must reproduce the above copyright 49 * notice, this list of conditions and the following disclaimer in the 50 * documentation and/or other materials provided with the distribution. 51 * 3. All advertising materials mentioning features or use of this software 52 * must display the following acknowledgement: 53 * This product includes software developed by the University of 54 * California, Berkeley and its contributors. 55 * 4. Neither the name of the University nor the names of its contributors 56 * may be used to endorse or promote products derived from this software 57 * without specific prior written permission. 58 * 59 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 60 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 61 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 62 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 63 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 64 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 65 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 66 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 67 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 68 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 69 * SUCH DAMAGE. 70 * 71 * @(#)kern_time.c 8.4 (Berkeley) 5/26/95 72 */ 73 74 #include "fs_nfs.h" 75 #include "opt_nfs.h" 76 #include "opt_nfsserver.h" 77 78 #include <sys/param.h> 79 #include <sys/resourcevar.h> 80 #include <sys/kernel.h> 81 #include <sys/systm.h> 82 #include <sys/lwp.h> 83 #include <sys/proc.h> 84 #include <sys/vnode.h> 85 #include <sys/signalvar.h> 86 #include <sys/syslog.h> 87 88 #include <sys/mount.h> 89 #include <sys/syscallargs.h> 90 91 #include <uvm/uvm_extern.h> 92 93 #if defined(NFS) || defined(NFSSERVER) 94 #include <nfs/rpcv2.h> 95 #include <nfs/nfsproto.h> 96 #include <nfs/nfs_var.h> 97 #endif 98 99 #include <machine/cpu.h> 100 101 /* 102 * Time of day and interval timer support. 103 * 104 * These routines provide the kernel entry points to get and set 105 * the time-of-day and per-process interval timers. Subroutines 106 * here provide support for adding and subtracting timeval structures 107 * and decrementing interval timers, optionally reloading the interval 108 * timers when they expire. 109 */ 110 111 /* This function is used by clock_settime and settimeofday */ 112 int 113 settime(tv) 114 struct timeval *tv; 115 { 116 struct timeval delta; 117 struct cpu_info *ci; 118 int s; 119 120 /* WHAT DO WE DO ABOUT PENDING REAL-TIME TIMEOUTS??? */ 121 s = splclock(); 122 timersub(tv, &time, &delta); 123 if ((delta.tv_sec < 0 || delta.tv_usec < 0) && securelevel > 1) { 124 splx(s); 125 return (EPERM); 126 } 127 #ifdef notyet 128 if ((delta.tv_sec < 86400) && securelevel > 0) { 129 splx(s); 130 return (EPERM); 131 } 132 #endif 133 time = *tv; 134 (void) spllowersoftclock(); 135 timeradd(&boottime, &delta, &boottime); 136 /* 137 * XXXSMP 138 * This is wrong. We should traverse a list of all 139 * CPUs and add the delta to the runtime of those 140 * CPUs which have a process on them. 141 */ 142 ci = curcpu(); 143 timeradd(&ci->ci_schedstate.spc_runtime, &delta, 144 &ci->ci_schedstate.spc_runtime); 145 # if (defined(NFS) && !defined (NFS_V2_ONLY)) || defined(NFSSERVER) 146 nqnfs_lease_updatetime(delta.tv_sec); 147 # endif 148 splx(s); 149 resettodr(); 150 return (0); 151 } 152 153 /* ARGSUSED */ 154 int 155 sys_clock_gettime(l, v, retval) 156 struct lwp *l; 157 void *v; 158 register_t *retval; 159 { 160 struct sys_clock_gettime_args /* { 161 syscallarg(clockid_t) clock_id; 162 syscallarg(struct timespec *) tp; 163 } */ *uap = v; 164 clockid_t clock_id; 165 struct timeval atv; 166 struct timespec ats; 167 168 clock_id = SCARG(uap, clock_id); 169 if (clock_id != CLOCK_REALTIME) 170 return (EINVAL); 171 172 microtime(&atv); 173 TIMEVAL_TO_TIMESPEC(&atv,&ats); 174 175 return copyout(&ats, SCARG(uap, tp), sizeof(ats)); 176 } 177 178 /* ARGSUSED */ 179 int 180 sys_clock_settime(l, v, retval) 181 struct lwp *l; 182 void *v; 183 register_t *retval; 184 { 185 struct sys_clock_settime_args /* { 186 syscallarg(clockid_t) clock_id; 187 syscallarg(const struct timespec *) tp; 188 } */ *uap = v; 189 struct proc *p = l->l_proc; 190 clockid_t clock_id; 191 struct timeval atv; 192 struct timespec ats; 193 int error; 194 195 if ((error = suser(p->p_ucred, &p->p_acflag)) != 0) 196 return (error); 197 198 clock_id = SCARG(uap, clock_id); 199 if (clock_id != CLOCK_REALTIME) 200 return (EINVAL); 201 202 if ((error = copyin(SCARG(uap, tp), &ats, sizeof(ats))) != 0) 203 return (error); 204 205 TIMESPEC_TO_TIMEVAL(&atv,&ats); 206 if ((error = settime(&atv))) 207 return (error); 208 209 return 0; 210 } 211 212 int 213 sys_clock_getres(l, v, retval) 214 struct lwp *l; 215 void *v; 216 register_t *retval; 217 { 218 struct sys_clock_getres_args /* { 219 syscallarg(clockid_t) clock_id; 220 syscallarg(struct timespec *) tp; 221 } */ *uap = v; 222 clockid_t clock_id; 223 struct timespec ts; 224 int error = 0; 225 226 clock_id = SCARG(uap, clock_id); 227 if (clock_id != CLOCK_REALTIME) 228 return (EINVAL); 229 230 if (SCARG(uap, tp)) { 231 ts.tv_sec = 0; 232 ts.tv_nsec = 1000000000 / hz; 233 234 error = copyout(&ts, SCARG(uap, tp), sizeof(ts)); 235 } 236 237 return error; 238 } 239 240 /* ARGSUSED */ 241 int 242 sys_nanosleep(l, v, retval) 243 struct lwp *l; 244 void *v; 245 register_t *retval; 246 { 247 static int nanowait; 248 struct sys_nanosleep_args/* { 249 syscallarg(struct timespec *) rqtp; 250 syscallarg(struct timespec *) rmtp; 251 } */ *uap = v; 252 struct timespec rqt; 253 struct timespec rmt; 254 struct timeval atv, utv; 255 int error, s, timo; 256 257 error = copyin((caddr_t)SCARG(uap, rqtp), (caddr_t)&rqt, 258 sizeof(struct timespec)); 259 if (error) 260 return (error); 261 262 TIMESPEC_TO_TIMEVAL(&atv,&rqt) 263 if (itimerfix(&atv)) 264 return (EINVAL); 265 266 s = splclock(); 267 timeradd(&atv,&time,&atv); 268 timo = hzto(&atv); 269 /* 270 * Avoid inadvertantly sleeping forever 271 */ 272 if (timo == 0) 273 timo = 1; 274 splx(s); 275 276 error = tsleep(&nanowait, PWAIT | PCATCH, "nanosleep", timo); 277 if (error == ERESTART) 278 error = EINTR; 279 if (error == EWOULDBLOCK) 280 error = 0; 281 282 if (SCARG(uap, rmtp)) { 283 int error; 284 285 s = splclock(); 286 utv = time; 287 splx(s); 288 289 timersub(&atv, &utv, &utv); 290 if (utv.tv_sec < 0) 291 timerclear(&utv); 292 293 TIMEVAL_TO_TIMESPEC(&utv,&rmt); 294 error = copyout((caddr_t)&rmt, (caddr_t)SCARG(uap,rmtp), 295 sizeof(rmt)); 296 if (error) 297 return (error); 298 } 299 300 return error; 301 } 302 303 /* ARGSUSED */ 304 int 305 sys_gettimeofday(l, v, retval) 306 struct lwp *l; 307 void *v; 308 register_t *retval; 309 { 310 struct sys_gettimeofday_args /* { 311 syscallarg(struct timeval *) tp; 312 syscallarg(struct timezone *) tzp; 313 } */ *uap = v; 314 struct timeval atv; 315 int error = 0; 316 struct timezone tzfake; 317 318 if (SCARG(uap, tp)) { 319 microtime(&atv); 320 error = copyout(&atv, SCARG(uap, tp), sizeof(atv)); 321 if (error) 322 return (error); 323 } 324 if (SCARG(uap, tzp)) { 325 /* 326 * NetBSD has no kernel notion of time zone, so we just 327 * fake up a timezone struct and return it if demanded. 328 */ 329 tzfake.tz_minuteswest = 0; 330 tzfake.tz_dsttime = 0; 331 error = copyout(&tzfake, SCARG(uap, tzp), sizeof(tzfake)); 332 } 333 return (error); 334 } 335 336 /* ARGSUSED */ 337 int 338 sys_settimeofday(l, v, retval) 339 struct lwp *l; 340 void *v; 341 register_t *retval; 342 { 343 struct sys_settimeofday_args /* { 344 syscallarg(const struct timeval *) tv; 345 syscallarg(const struct timezone *) tzp; 346 } */ *uap = v; 347 struct proc *p = l->l_proc; 348 struct timeval atv; 349 struct timezone atz; 350 int error; 351 352 if ((error = suser(p->p_ucred, &p->p_acflag)) != 0) 353 return (error); 354 /* Verify all parameters before changing time. */ 355 if (SCARG(uap, tv) && (error = copyin(SCARG(uap, tv), 356 &atv, sizeof(atv)))) 357 return (error); 358 /* XXX since we don't use tz, probably no point in doing copyin. */ 359 if (SCARG(uap, tzp) && (error = copyin(SCARG(uap, tzp), 360 &atz, sizeof(atz)))) 361 return (error); 362 if (SCARG(uap, tv)) 363 if ((error = settime(&atv))) 364 return (error); 365 /* 366 * NetBSD has no kernel notion of time zone, and only an 367 * obsolete program would try to set it, so we log a warning. 368 */ 369 if (SCARG(uap, tzp)) 370 log(LOG_WARNING, "pid %d attempted to set the " 371 "(obsolete) kernel time zone\n", p->p_pid); 372 return (0); 373 } 374 375 int tickdelta; /* current clock skew, us. per tick */ 376 long timedelta; /* unapplied time correction, us. */ 377 long bigadj = 1000000; /* use 10x skew above bigadj us. */ 378 379 /* ARGSUSED */ 380 int 381 sys_adjtime(l, v, retval) 382 struct lwp *l; 383 void *v; 384 register_t *retval; 385 { 386 struct sys_adjtime_args /* { 387 syscallarg(const struct timeval *) delta; 388 syscallarg(struct timeval *) olddelta; 389 } */ *uap = v; 390 struct proc *p = l->l_proc; 391 struct timeval atv; 392 long ndelta, ntickdelta, odelta; 393 int s, error; 394 395 if ((error = suser(p->p_ucred, &p->p_acflag)) != 0) 396 return (error); 397 398 error = copyin(SCARG(uap, delta), &atv, sizeof(struct timeval)); 399 if (error) 400 return (error); 401 if (SCARG(uap, olddelta) != NULL && 402 uvm_useracc((caddr_t)SCARG(uap, olddelta), sizeof(struct timeval), 403 B_WRITE) == FALSE) 404 return (EFAULT); 405 406 /* 407 * Compute the total correction and the rate at which to apply it. 408 * Round the adjustment down to a whole multiple of the per-tick 409 * delta, so that after some number of incremental changes in 410 * hardclock(), tickdelta will become zero, lest the correction 411 * overshoot and start taking us away from the desired final time. 412 */ 413 ndelta = atv.tv_sec * 1000000 + atv.tv_usec; 414 if (ndelta > bigadj || ndelta < -bigadj) 415 ntickdelta = 10 * tickadj; 416 else 417 ntickdelta = tickadj; 418 if (ndelta % ntickdelta) 419 ndelta = ndelta / ntickdelta * ntickdelta; 420 421 /* 422 * To make hardclock()'s job easier, make the per-tick delta negative 423 * if we want time to run slower; then hardclock can simply compute 424 * tick + tickdelta, and subtract tickdelta from timedelta. 425 */ 426 if (ndelta < 0) 427 ntickdelta = -ntickdelta; 428 s = splclock(); 429 odelta = timedelta; 430 timedelta = ndelta; 431 tickdelta = ntickdelta; 432 splx(s); 433 434 if (SCARG(uap, olddelta)) { 435 atv.tv_sec = odelta / 1000000; 436 atv.tv_usec = odelta % 1000000; 437 (void) copyout(&atv, SCARG(uap, olddelta), 438 sizeof(struct timeval)); 439 } 440 return (0); 441 } 442 443 /* 444 * Get value of an interval timer. The process virtual and 445 * profiling virtual time timers are kept in the p_stats area, since 446 * they can be swapped out. These are kept internally in the 447 * way they are specified externally: in time until they expire. 448 * 449 * The real time interval timer is kept in the process table slot 450 * for the process, and its value (it_value) is kept as an 451 * absolute time rather than as a delta, so that it is easy to keep 452 * periodic real-time signals from drifting. 453 * 454 * Virtual time timers are processed in the hardclock() routine of 455 * kern_clock.c. The real time timer is processed by a timeout 456 * routine, called from the softclock() routine. Since a callout 457 * may be delayed in real time due to interrupt processing in the system, 458 * it is possible for the real time timeout routine (realitexpire, given below), 459 * to be delayed in real time past when it is supposed to occur. It 460 * does not suffice, therefore, to reload the real timer .it_value from the 461 * real time timers .it_interval. Rather, we compute the next time in 462 * absolute time the timer should go off. 463 */ 464 /* ARGSUSED */ 465 int 466 sys_getitimer(l, v, retval) 467 struct lwp *l; 468 void *v; 469 register_t *retval; 470 { 471 struct sys_getitimer_args /* { 472 syscallarg(int) which; 473 syscallarg(struct itimerval *) itv; 474 } */ *uap = v; 475 struct proc *p = l->l_proc; 476 int which = SCARG(uap, which); 477 struct itimerval aitv; 478 int s; 479 480 if ((u_int)which > ITIMER_PROF) 481 return (EINVAL); 482 s = splclock(); 483 if (which == ITIMER_REAL) { 484 /* 485 * Convert from absolute to relative time in .it_value 486 * part of real time timer. If time for real time timer 487 * has passed return 0, else return difference between 488 * current time and time for the timer to go off. 489 */ 490 aitv = p->p_realtimer; 491 if (timerisset(&aitv.it_value)) { 492 if (timercmp(&aitv.it_value, &time, <)) 493 timerclear(&aitv.it_value); 494 else 495 timersub(&aitv.it_value, &time, &aitv.it_value); 496 } 497 } else 498 aitv = p->p_stats->p_timer[which]; 499 splx(s); 500 return (copyout(&aitv, SCARG(uap, itv), sizeof(struct itimerval))); 501 } 502 503 /* ARGSUSED */ 504 int 505 sys_setitimer(l, v, retval) 506 struct lwp *l; 507 void *v; 508 register_t *retval; 509 { 510 struct sys_setitimer_args /* { 511 syscallarg(int) which; 512 syscallarg(const struct itimerval *) itv; 513 syscallarg(struct itimerval *) oitv; 514 } */ *uap = v; 515 struct proc *p = l->l_proc; 516 int which = SCARG(uap, which); 517 struct sys_getitimer_args getargs; 518 struct itimerval aitv; 519 const struct itimerval *itvp; 520 int s, error; 521 522 if ((u_int)which > ITIMER_PROF) 523 return (EINVAL); 524 itvp = SCARG(uap, itv); 525 if (itvp && (error = copyin(itvp, &aitv, sizeof(struct itimerval)))) 526 return (error); 527 if (SCARG(uap, oitv) != NULL) { 528 SCARG(&getargs, which) = which; 529 SCARG(&getargs, itv) = SCARG(uap, oitv); 530 if ((error = sys_getitimer(l, &getargs, retval)) != 0) 531 return (error); 532 } 533 if (itvp == 0) 534 return (0); 535 if (itimerfix(&aitv.it_value) || itimerfix(&aitv.it_interval)) 536 return (EINVAL); 537 s = splclock(); 538 if (which == ITIMER_REAL) { 539 callout_stop(&p->p_realit_ch); 540 if (timerisset(&aitv.it_value)) { 541 /* 542 * Don't need to check hzto() return value, here. 543 * callout_reset() does it for us. 544 */ 545 timeradd(&aitv.it_value, &time, &aitv.it_value); 546 callout_reset(&p->p_realit_ch, hzto(&aitv.it_value), 547 realitexpire, p); 548 } 549 p->p_realtimer = aitv; 550 } else 551 p->p_stats->p_timer[which] = aitv; 552 splx(s); 553 return (0); 554 } 555 556 /* 557 * Real interval timer expired: 558 * send process whose timer expired an alarm signal. 559 * If time is not set up to reload, then just return. 560 * Else compute next time timer should go off which is > current time. 561 * This is where delay in processing this timeout causes multiple 562 * SIGALRM calls to be compressed into one. 563 */ 564 void 565 realitexpire(arg) 566 void *arg; 567 { 568 struct proc *p; 569 int s; 570 571 p = (struct proc *)arg; 572 psignal(p, SIGALRM); 573 if (!timerisset(&p->p_realtimer.it_interval)) { 574 timerclear(&p->p_realtimer.it_value); 575 return; 576 } 577 for (;;) { 578 s = splclock(); 579 timeradd(&p->p_realtimer.it_value, 580 &p->p_realtimer.it_interval, &p->p_realtimer.it_value); 581 if (timercmp(&p->p_realtimer.it_value, &time, >)) { 582 /* 583 * Don't need to check hzto() return value, here. 584 * callout_reset() does it for us. 585 */ 586 callout_reset(&p->p_realit_ch, 587 hzto(&p->p_realtimer.it_value), realitexpire, p); 588 splx(s); 589 return; 590 } 591 splx(s); 592 } 593 } 594 595 /* 596 * Check that a proposed value to load into the .it_value or 597 * .it_interval part of an interval timer is acceptable, and 598 * fix it to have at least minimal value (i.e. if it is less 599 * than the resolution of the clock, round it up.) 600 */ 601 int 602 itimerfix(tv) 603 struct timeval *tv; 604 { 605 606 if (tv->tv_sec < 0 || tv->tv_sec > 100000000 || 607 tv->tv_usec < 0 || tv->tv_usec >= 1000000) 608 return (EINVAL); 609 if (tv->tv_sec == 0 && tv->tv_usec != 0 && tv->tv_usec < tick) 610 tv->tv_usec = tick; 611 return (0); 612 } 613 614 /* 615 * Decrement an interval timer by a specified number 616 * of microseconds, which must be less than a second, 617 * i.e. < 1000000. If the timer expires, then reload 618 * it. In this case, carry over (usec - old value) to 619 * reduce the value reloaded into the timer so that 620 * the timer does not drift. This routine assumes 621 * that it is called in a context where the timers 622 * on which it is operating cannot change in value. 623 */ 624 int 625 itimerdecr(itp, usec) 626 struct itimerval *itp; 627 int usec; 628 { 629 630 if (itp->it_value.tv_usec < usec) { 631 if (itp->it_value.tv_sec == 0) { 632 /* expired, and already in next interval */ 633 usec -= itp->it_value.tv_usec; 634 goto expire; 635 } 636 itp->it_value.tv_usec += 1000000; 637 itp->it_value.tv_sec--; 638 } 639 itp->it_value.tv_usec -= usec; 640 usec = 0; 641 if (timerisset(&itp->it_value)) 642 return (1); 643 /* expired, exactly at end of interval */ 644 expire: 645 if (timerisset(&itp->it_interval)) { 646 itp->it_value = itp->it_interval; 647 itp->it_value.tv_usec -= usec; 648 if (itp->it_value.tv_usec < 0) { 649 itp->it_value.tv_usec += 1000000; 650 itp->it_value.tv_sec--; 651 } 652 } else 653 itp->it_value.tv_usec = 0; /* sec is already 0 */ 654 return (0); 655 } 656 657 /* 658 * ratecheck(): simple time-based rate-limit checking. see ratecheck(9) 659 * for usage and rationale. 660 */ 661 int 662 ratecheck(lasttime, mininterval) 663 struct timeval *lasttime; 664 const struct timeval *mininterval; 665 { 666 struct timeval tv, delta; 667 int s, rv = 0; 668 669 s = splclock(); 670 tv = mono_time; 671 splx(s); 672 673 timersub(&tv, lasttime, &delta); 674 675 /* 676 * check for 0,0 is so that the message will be seen at least once, 677 * even if interval is huge. 678 */ 679 if (timercmp(&delta, mininterval, >=) || 680 (lasttime->tv_sec == 0 && lasttime->tv_usec == 0)) { 681 *lasttime = tv; 682 rv = 1; 683 } 684 685 return (rv); 686 } 687 688 /* 689 * ppsratecheck(): packets (or events) per second limitation. 690 */ 691 int 692 ppsratecheck(lasttime, curpps, maxpps) 693 struct timeval *lasttime; 694 int *curpps; 695 int maxpps; /* maximum pps allowed */ 696 { 697 struct timeval tv, delta; 698 int s, rv; 699 700 s = splclock(); 701 tv = mono_time; 702 splx(s); 703 704 timersub(&tv, lasttime, &delta); 705 706 /* 707 * check for 0,0 is so that the message will be seen at least once. 708 * if more than one second have passed since the last update of 709 * lasttime, reset the counter. 710 * 711 * we do increment *curpps even in *curpps < maxpps case, as some may 712 * try to use *curpps for stat purposes as well. 713 */ 714 if ((lasttime->tv_sec == 0 && lasttime->tv_usec == 0) || 715 delta.tv_sec >= 1) { 716 *lasttime = tv; 717 *curpps = 0; 718 rv = 1; 719 } else if (maxpps < 0) 720 rv = 1; 721 else if (*curpps < maxpps) 722 rv = 1; 723 else 724 rv = 0; 725 726 #if 1 /*DIAGNOSTIC?*/ 727 /* be careful about wrap-around */ 728 if (*curpps + 1 > *curpps) 729 *curpps = *curpps + 1; 730 #else 731 /* 732 * assume that there's not too many calls to this function. 733 * not sure if the assumption holds, as it depends on *caller's* 734 * behavior, not the behavior of this function. 735 * IMHO it is wrong to make assumption on the caller's behavior, 736 * so the above #if is #if 1, not #ifdef DIAGNOSTIC. 737 */ 738 *curpps = *curpps + 1; 739 #endif 740 741 return (rv); 742 } 743
Indexes created Tue Sep 30 06:09:59 GMT 2025