kern_time.c revision 1.57 1 /* $NetBSD: kern_time.c,v 1.57 2001/11/12 14:52:33 christos 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/proc.h>
83 #include <sys/vnode.h>
84 #include <sys/signalvar.h>
85 #include <sys/syslog.h>
86
87 #include <sys/mount.h>
88 #include <sys/syscallargs.h>
89
90 #include <uvm/uvm_extern.h>
91
92 #if defined(NFS) || defined(NFSSERVER)
93 #include <nfs/rpcv2.h>
94 #include <nfs/nfsproto.h>
95 #include <nfs/nfs_var.h>
96 #endif
97
98 #include <machine/cpu.h>
99
100 /*
101 * Time of day and interval timer support.
102 *
103 * These routines provide the kernel entry points to get and set
104 * the time-of-day and per-process interval timers. Subroutines
105 * here provide support for adding and subtracting timeval structures
106 * and decrementing interval timers, optionally reloading the interval
107 * timers when they expire.
108 */
109
110 /* This function is used by clock_settime and settimeofday */
111 int
112 settime(tv)
113 struct timeval *tv;
114 {
115 struct timeval delta;
116 struct cpu_info *ci;
117 int s;
118
119 /* WHAT DO WE DO ABOUT PENDING REAL-TIME TIMEOUTS??? */
120 s = splclock();
121 timersub(tv, &time, &delta);
122 if ((delta.tv_sec < 0 || delta.tv_usec < 0) && securelevel > 1) {
123 splx(s);
124 return (EPERM);
125 }
126 #ifdef notyet
127 if ((delta.tv_sec < 86400) && securelevel > 0) {
128 splx(s);
129 return (EPERM);
130 }
131 #endif
132 time = *tv;
133 (void) spllowersoftclock();
134 timeradd(&boottime, &delta, &boottime);
135 /*
136 * XXXSMP
137 * This is wrong. We should traverse a list of all
138 * CPUs and add the delta to the runtime of those
139 * CPUs which have a process on them.
140 */
141 ci = curcpu();
142 timeradd(&ci->ci_schedstate.spc_runtime, &delta,
143 &ci->ci_schedstate.spc_runtime);
144 # if (defined(NFS) && !defined (NFS_V2_ONLY)) || defined(NFSSERVER)
145 nqnfs_lease_updatetime(delta.tv_sec);
146 # endif
147 splx(s);
148 resettodr();
149 return (0);
150 }
151
152 /* ARGSUSED */
153 int
154 sys_clock_gettime(p, v, retval)
155 struct proc *p;
156 void *v;
157 register_t *retval;
158 {
159 struct sys_clock_gettime_args /* {
160 syscallarg(clockid_t) clock_id;
161 syscallarg(struct timespec *) tp;
162 } */ *uap = v;
163 clockid_t clock_id;
164 struct timeval atv;
165 struct timespec ats;
166
167 clock_id = SCARG(uap, clock_id);
168 if (clock_id != CLOCK_REALTIME)
169 return (EINVAL);
170
171 microtime(&atv);
172 TIMEVAL_TO_TIMESPEC(&atv,&ats);
173
174 return copyout(&ats, SCARG(uap, tp), sizeof(ats));
175 }
176
177 /* ARGSUSED */
178 int
179 sys_clock_settime(p, v, retval)
180 struct proc *p;
181 void *v;
182 register_t *retval;
183 {
184 struct sys_clock_settime_args /* {
185 syscallarg(clockid_t) clock_id;
186 syscallarg(const struct timespec *) tp;
187 } */ *uap = v;
188 clockid_t clock_id;
189 struct timespec ats;
190 int error;
191
192 if ((error = suser(p->p_ucred, &p->p_acflag)) != 0)
193 return (error);
194
195 clock_id = SCARG(uap, clock_id);
196
197 if ((error = copyin(SCARG(uap, tp), &ats, sizeof(ats))) != 0)
198 return (error);
199
200 return (clock_settime1(clock_id, &ats));
201 }
202
203
204 int
205 clock_settime1(clock_id, ats)
206 clockid_t clock_id;
207 struct timespec *ats;
208 {
209 struct timeval atv;
210 int error;
211
212 if (clock_id != CLOCK_REALTIME)
213 return (EINVAL);
214
215 TIMESPEC_TO_TIMEVAL(&atv, ats);
216 if ((error = settime(&atv)) != 0)
217 return (error);
218
219 return 0;
220 }
221
222 int
223 sys_clock_getres(p, v, retval)
224 struct proc *p;
225 void *v;
226 register_t *retval;
227 {
228 struct sys_clock_getres_args /* {
229 syscallarg(clockid_t) clock_id;
230 syscallarg(struct timespec *) tp;
231 } */ *uap = v;
232 clockid_t clock_id;
233 struct timespec ts;
234 int error = 0;
235
236 clock_id = SCARG(uap, clock_id);
237 if (clock_id != CLOCK_REALTIME)
238 return (EINVAL);
239
240 if (SCARG(uap, tp)) {
241 ts.tv_sec = 0;
242 ts.tv_nsec = 1000000000 / hz;
243
244 error = copyout(&ts, SCARG(uap, tp), sizeof(ts));
245 }
246
247 return error;
248 }
249
250 /* ARGSUSED */
251 int
252 sys_nanosleep(p, v, retval)
253 struct proc *p;
254 void *v;
255 register_t *retval;
256 {
257 static int nanowait;
258 struct sys_nanosleep_args/* {
259 syscallarg(struct timespec *) rqtp;
260 syscallarg(struct timespec *) rmtp;
261 } */ *uap = v;
262 struct timespec rqt;
263 struct timespec rmt;
264 struct timeval atv, utv;
265 int error, s, timo;
266
267 error = copyin((caddr_t)SCARG(uap, rqtp), (caddr_t)&rqt,
268 sizeof(struct timespec));
269 if (error)
270 return (error);
271
272 TIMESPEC_TO_TIMEVAL(&atv,&rqt)
273 if (itimerfix(&atv))
274 return (EINVAL);
275
276 s = splclock();
277 timeradd(&atv,&time,&atv);
278 timo = hzto(&atv);
279 /*
280 * Avoid inadvertantly sleeping forever
281 */
282 if (timo == 0)
283 timo = 1;
284 splx(s);
285
286 error = tsleep(&nanowait, PWAIT | PCATCH, "nanosleep", timo);
287 if (error == ERESTART)
288 error = EINTR;
289 if (error == EWOULDBLOCK)
290 error = 0;
291
292 if (SCARG(uap, rmtp)) {
293 int error;
294
295 s = splclock();
296 utv = time;
297 splx(s);
298
299 timersub(&atv, &utv, &utv);
300 if (utv.tv_sec < 0)
301 timerclear(&utv);
302
303 TIMEVAL_TO_TIMESPEC(&utv,&rmt);
304 error = copyout((caddr_t)&rmt, (caddr_t)SCARG(uap,rmtp),
305 sizeof(rmt));
306 if (error)
307 return (error);
308 }
309
310 return error;
311 }
312
313 /* ARGSUSED */
314 int
315 sys_gettimeofday(p, v, retval)
316 struct proc *p;
317 void *v;
318 register_t *retval;
319 {
320 struct sys_gettimeofday_args /* {
321 syscallarg(struct timeval *) tp;
322 syscallarg(struct timezone *) tzp;
323 } */ *uap = v;
324 struct timeval atv;
325 int error = 0;
326 struct timezone tzfake;
327
328 if (SCARG(uap, tp)) {
329 microtime(&atv);
330 error = copyout(&atv, SCARG(uap, tp), sizeof(atv));
331 if (error)
332 return (error);
333 }
334 if (SCARG(uap, tzp)) {
335 /*
336 * NetBSD has no kernel notion of time zone, so we just
337 * fake up a timezone struct and return it if demanded.
338 */
339 tzfake.tz_minuteswest = 0;
340 tzfake.tz_dsttime = 0;
341 error = copyout(&tzfake, SCARG(uap, tzp), sizeof(tzfake));
342 }
343 return (error);
344 }
345
346 /* ARGSUSED */
347 int
348 sys_settimeofday(p, v, retval)
349 struct proc *p;
350 void *v;
351 register_t *retval;
352 {
353 struct sys_settimeofday_args /* {
354 syscallarg(const struct timeval *) tv;
355 syscallarg(const struct timezone *) tzp;
356 } */ *uap = v;
357 struct timeval atv;
358 struct timezone atz;
359 struct timeval *tv = NULL;
360 struct timezone *tzp = NULL;
361 int error;
362
363 if ((error = suser(p->p_ucred, &p->p_acflag)) != 0)
364 return (error);
365
366 /* Verify all parameters before changing time. */
367 if (SCARG(uap, tv)) {
368 if ((error = copyin(SCARG(uap, tv), &atv, sizeof(atv))) != 0)
369 return (error);
370 tv = &atv;
371 }
372 /* XXX since we don't use tz, probably no point in doing copyin. */
373 if (SCARG(uap, tzp)) {
374 if ((error = copyin(SCARG(uap, tzp), &atz, sizeof(atz))) != 0)
375 return (error);
376 tzp = &atz;
377 }
378
379 return settimeofday1(tv, tzp, p);
380 }
381
382 int
383 settimeofday1(tv, tzp, p)
384 struct timeval *tv;
385 struct timezone *tzp;
386 struct proc *p;
387 {
388 int error;
389
390 if (tv)
391 if ((error = settime(tv)) != 0)
392 return (error);
393 /*
394 * NetBSD has no kernel notion of time zone, and only an
395 * obsolete program would try to set it, so we log a warning.
396 */
397 if (tzp)
398 log(LOG_WARNING, "pid %d attempted to set the "
399 "(obsolete) kernel time zone\n", p->p_pid);
400 return (0);
401 }
402
403 int tickdelta; /* current clock skew, us. per tick */
404 long timedelta; /* unapplied time correction, us. */
405 long bigadj = 1000000; /* use 10x skew above bigadj us. */
406
407 /* ARGSUSED */
408 int
409 sys_adjtime(p, v, retval)
410 struct proc *p;
411 void *v;
412 register_t *retval;
413 {
414 struct sys_adjtime_args /* {
415 syscallarg(const struct timeval *) delta;
416 syscallarg(struct timeval *) olddelta;
417 } */ *uap = v;
418 struct timeval atv;
419 struct timeval *oatv = NULL;
420 int error;
421
422 if ((error = suser(p->p_ucred, &p->p_acflag)) != 0)
423 return (error);
424
425 error = copyin(SCARG(uap, delta), &atv, sizeof(struct timeval));
426 if (error)
427 return (error);
428
429 if (SCARG(uap, olddelta) != NULL) {
430 if (uvm_useracc((caddr_t)SCARG(uap, olddelta),
431 sizeof(struct timeval), B_WRITE) == FALSE)
432 return (EFAULT);
433 oatv = SCARG(uap, olddelta);
434 }
435
436 return adjtime1(&atv, oatv, p);
437 }
438
439 int
440 adjtime1(delta, olddelta, p)
441 struct timeval *delta;
442 struct timeval *olddelta;
443 struct proc *p;
444 {
445 long ndelta, ntickdelta, odelta;
446 int s;
447
448 /*
449 * Compute the total correction and the rate at which to apply it.
450 * Round the adjustment down to a whole multiple of the per-tick
451 * delta, so that after some number of incremental changes in
452 * hardclock(), tickdelta will become zero, lest the correction
453 * overshoot and start taking us away from the desired final time.
454 */
455 ndelta = delta->tv_sec * 1000000 + delta->tv_usec;
456 if (ndelta > bigadj || ndelta < -bigadj)
457 ntickdelta = 10 * tickadj;
458 else
459 ntickdelta = tickadj;
460 if (ndelta % ntickdelta)
461 ndelta = ndelta / ntickdelta * ntickdelta;
462
463 /*
464 * To make hardclock()'s job easier, make the per-tick delta negative
465 * if we want time to run slower; then hardclock can simply compute
466 * tick + tickdelta, and subtract tickdelta from timedelta.
467 */
468 if (ndelta < 0)
469 ntickdelta = -ntickdelta;
470 s = splclock();
471 odelta = timedelta;
472 timedelta = ndelta;
473 tickdelta = ntickdelta;
474 splx(s);
475
476 if (olddelta) {
477 delta->tv_sec = odelta / 1000000;
478 delta->tv_usec = odelta % 1000000;
479 (void) copyout(delta, olddelta, sizeof(struct timeval));
480 }
481 return (0);
482 }
483
484 /*
485 * Get value of an interval timer. The process virtual and
486 * profiling virtual time timers are kept in the p_stats area, since
487 * they can be swapped out. These are kept internally in the
488 * way they are specified externally: in time until they expire.
489 *
490 * The real time interval timer is kept in the process table slot
491 * for the process, and its value (it_value) is kept as an
492 * absolute time rather than as a delta, so that it is easy to keep
493 * periodic real-time signals from drifting.
494 *
495 * Virtual time timers are processed in the hardclock() routine of
496 * kern_clock.c. The real time timer is processed by a timeout
497 * routine, called from the softclock() routine. Since a callout
498 * may be delayed in real time due to interrupt processing in the system,
499 * it is possible for the real time timeout routine (realitexpire, given below),
500 * to be delayed in real time past when it is supposed to occur. It
501 * does not suffice, therefore, to reload the real timer .it_value from the
502 * real time timers .it_interval. Rather, we compute the next time in
503 * absolute time the timer should go off.
504 */
505 /* ARGSUSED */
506 int
507 sys_getitimer(p, v, retval)
508 struct proc *p;
509 void *v;
510 register_t *retval;
511 {
512 struct sys_getitimer_args /* {
513 syscallarg(int) which;
514 syscallarg(struct itimerval *) itv;
515 } */ *uap = v;
516 int which = SCARG(uap, which);
517 struct itimerval aitv;
518 int s;
519
520 if ((u_int)which > ITIMER_PROF)
521 return (EINVAL);
522 s = splclock();
523 if (which == ITIMER_REAL) {
524 /*
525 * Convert from absolute to relative time in .it_value
526 * part of real time timer. If time for real time timer
527 * has passed return 0, else return difference between
528 * current time and time for the timer to go off.
529 */
530 aitv = p->p_realtimer;
531 if (timerisset(&aitv.it_value)) {
532 if (timercmp(&aitv.it_value, &time, <))
533 timerclear(&aitv.it_value);
534 else
535 timersub(&aitv.it_value, &time, &aitv.it_value);
536 }
537 } else
538 aitv = p->p_stats->p_timer[which];
539 splx(s);
540 return (copyout(&aitv, SCARG(uap, itv), sizeof(struct itimerval)));
541 }
542
543 /* ARGSUSED */
544 int
545 sys_setitimer(p, v, retval)
546 struct proc *p;
547 void *v;
548 register_t *retval;
549 {
550 struct sys_setitimer_args /* {
551 syscallarg(int) which;
552 syscallarg(const struct itimerval *) itv;
553 syscallarg(struct itimerval *) oitv;
554 } */ *uap = v;
555 int which = SCARG(uap, which);
556 struct sys_getitimer_args getargs;
557 struct itimerval aitv;
558 const struct itimerval *itvp;
559 int s, error;
560
561 if ((u_int)which > ITIMER_PROF)
562 return (EINVAL);
563 itvp = SCARG(uap, itv);
564 if (itvp &&
565 (error = copyin(itvp, &aitv, sizeof(struct itimerval)) != 0))
566 return (error);
567 if (SCARG(uap, oitv) != NULL) {
568 SCARG(&getargs, which) = which;
569 SCARG(&getargs, itv) = SCARG(uap, oitv);
570 if ((error = sys_getitimer(p, &getargs, retval)) != 0)
571 return (error);
572 }
573 if (itvp == 0)
574 return (0);
575 if (itimerfix(&aitv.it_value) || itimerfix(&aitv.it_interval))
576 return (EINVAL);
577 s = splclock();
578 if (which == ITIMER_REAL) {
579 callout_stop(&p->p_realit_ch);
580 if (timerisset(&aitv.it_value)) {
581 /*
582 * Don't need to check hzto() return value, here.
583 * callout_reset() does it for us.
584 */
585 timeradd(&aitv.it_value, &time, &aitv.it_value);
586 callout_reset(&p->p_realit_ch, hzto(&aitv.it_value),
587 realitexpire, p);
588 }
589 p->p_realtimer = aitv;
590 } else
591 p->p_stats->p_timer[which] = aitv;
592 splx(s);
593 return (0);
594 }
595
596 /*
597 * Real interval timer expired:
598 * send process whose timer expired an alarm signal.
599 * If time is not set up to reload, then just return.
600 * Else compute next time timer should go off which is > current time.
601 * This is where delay in processing this timeout causes multiple
602 * SIGALRM calls to be compressed into one.
603 */
604 void
605 realitexpire(arg)
606 void *arg;
607 {
608 struct proc *p;
609 int s;
610
611 p = (struct proc *)arg;
612 psignal(p, SIGALRM);
613 if (!timerisset(&p->p_realtimer.it_interval)) {
614 timerclear(&p->p_realtimer.it_value);
615 return;
616 }
617 for (;;) {
618 s = splclock();
619 timeradd(&p->p_realtimer.it_value,
620 &p->p_realtimer.it_interval, &p->p_realtimer.it_value);
621 if (timercmp(&p->p_realtimer.it_value, &time, >)) {
622 /*
623 * Don't need to check hzto() return value, here.
624 * callout_reset() does it for us.
625 */
626 callout_reset(&p->p_realit_ch,
627 hzto(&p->p_realtimer.it_value), realitexpire, p);
628 splx(s);
629 return;
630 }
631 splx(s);
632 }
633 }
634
635 /*
636 * Check that a proposed value to load into the .it_value or
637 * .it_interval part of an interval timer is acceptable, and
638 * fix it to have at least minimal value (i.e. if it is less
639 * than the resolution of the clock, round it up.)
640 */
641 int
642 itimerfix(tv)
643 struct timeval *tv;
644 {
645
646 if (tv->tv_sec < 0 || tv->tv_sec > 1000000000 ||
647 tv->tv_usec < 0 || tv->tv_usec >= 1000000)
648 return (EINVAL);
649 if (tv->tv_sec == 0 && tv->tv_usec != 0 && tv->tv_usec < tick)
650 tv->tv_usec = tick;
651 return (0);
652 }
653
654 /*
655 * Decrement an interval timer by a specified number
656 * of microseconds, which must be less than a second,
657 * i.e. < 1000000. If the timer expires, then reload
658 * it. In this case, carry over (usec - old value) to
659 * reduce the value reloaded into the timer so that
660 * the timer does not drift. This routine assumes
661 * that it is called in a context where the timers
662 * on which it is operating cannot change in value.
663 */
664 int
665 itimerdecr(itp, usec)
666 struct itimerval *itp;
667 int usec;
668 {
669
670 if (itp->it_value.tv_usec < usec) {
671 if (itp->it_value.tv_sec == 0) {
672 /* expired, and already in next interval */
673 usec -= itp->it_value.tv_usec;
674 goto expire;
675 }
676 itp->it_value.tv_usec += 1000000;
677 itp->it_value.tv_sec--;
678 }
679 itp->it_value.tv_usec -= usec;
680 usec = 0;
681 if (timerisset(&itp->it_value))
682 return (1);
683 /* expired, exactly at end of interval */
684 expire:
685 if (timerisset(&itp->it_interval)) {
686 itp->it_value = itp->it_interval;
687 itp->it_value.tv_usec -= usec;
688 if (itp->it_value.tv_usec < 0) {
689 itp->it_value.tv_usec += 1000000;
690 itp->it_value.tv_sec--;
691 }
692 } else
693 itp->it_value.tv_usec = 0; /* sec is already 0 */
694 return (0);
695 }
696
697 /*
698 * ratecheck(): simple time-based rate-limit checking. see ratecheck(9)
699 * for usage and rationale.
700 */
701 int
702 ratecheck(lasttime, mininterval)
703 struct timeval *lasttime;
704 const struct timeval *mininterval;
705 {
706 struct timeval tv, delta;
707 int s, rv = 0;
708
709 s = splclock();
710 tv = mono_time;
711 splx(s);
712
713 timersub(&tv, lasttime, &delta);
714
715 /*
716 * check for 0,0 is so that the message will be seen at least once,
717 * even if interval is huge.
718 */
719 if (timercmp(&delta, mininterval, >=) ||
720 (lasttime->tv_sec == 0 && lasttime->tv_usec == 0)) {
721 *lasttime = tv;
722 rv = 1;
723 }
724
725 return (rv);
726 }
727
728 /*
729 * ppsratecheck(): packets (or events) per second limitation.
730 */
731 int
732 ppsratecheck(lasttime, curpps, maxpps)
733 struct timeval *lasttime;
734 int *curpps;
735 int maxpps; /* maximum pps allowed */
736 {
737 struct timeval tv, delta;
738 int s, rv;
739
740 s = splclock();
741 tv = mono_time;
742 splx(s);
743
744 timersub(&tv, lasttime, &delta);
745
746 /*
747 * check for 0,0 is so that the message will be seen at least once.
748 * if more than one second have passed since the last update of
749 * lasttime, reset the counter.
750 *
751 * we do increment *curpps even in *curpps < maxpps case, as some may
752 * try to use *curpps for stat purposes as well.
753 */
754 if ((lasttime->tv_sec == 0 && lasttime->tv_usec == 0) ||
755 delta.tv_sec >= 1) {
756 *lasttime = tv;
757 *curpps = 0;
758 rv = 1;
759 } else if (maxpps < 0)
760 rv = 1;
761 else if (*curpps < maxpps)
762 rv = 1;
763 else
764 rv = 0;
765
766 #if 1 /*DIAGNOSTIC?*/
767 /* be careful about wrap-around */
768 if (*curpps + 1 > *curpps)
769 *curpps = *curpps + 1;
770 #else
771 /*
772 * assume that there's not too many calls to this function.
773 * not sure if the assumption holds, as it depends on *caller's*
774 * behavior, not the behavior of this function.
775 * IMHO it is wrong to make assumption on the caller's behavior,
776 * so the above #if is #if 1, not #ifdef DIAGNOSTIC.
777 */
778 *curpps = *curpps + 1;
779 #endif
780
781 return (rv);
782 }
783