kern_time.c revision 99012
11541Srgrimes/* 21541Srgrimes * Copyright (c) 1982, 1986, 1989, 1993 31541Srgrimes * The Regents of the University of California. All rights reserved. 41541Srgrimes * 51541Srgrimes * Redistribution and use in source and binary forms, with or without 61541Srgrimes * modification, are permitted provided that the following conditions 71541Srgrimes * are met: 81541Srgrimes * 1. Redistributions of source code must retain the above copyright 91541Srgrimes * notice, this list of conditions and the following disclaimer. 101541Srgrimes * 2. Redistributions in binary form must reproduce the above copyright 111541Srgrimes * notice, this list of conditions and the following disclaimer in the 121541Srgrimes * documentation and/or other materials provided with the distribution. 131541Srgrimes * 3. All advertising materials mentioning features or use of this software 141541Srgrimes * must display the following acknowledgement: 151541Srgrimes * This product includes software developed by the University of 161541Srgrimes * California, Berkeley and its contributors. 171541Srgrimes * 4. Neither the name of the University nor the names of its contributors 181541Srgrimes * may be used to endorse or promote products derived from this software 191541Srgrimes * without specific prior written permission. 201541Srgrimes * 211541Srgrimes * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 221541Srgrimes * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 231541Srgrimes * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 241541Srgrimes * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 251541Srgrimes * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 261541Srgrimes * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 271541Srgrimes * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 281541Srgrimes * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 291541Srgrimes * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 301541Srgrimes * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 311541Srgrimes * SUCH DAMAGE. 321541Srgrimes * 331541Srgrimes * @(#)kern_time.c 8.1 (Berkeley) 6/10/93 3450477Speter * $FreeBSD: head/sys/kern/kern_time.c 99012 2002-06-29 02:00:02Z alfred $ 351541Srgrimes */ 361541Srgrimes 371541Srgrimes#include <sys/param.h> 3848274Speter#include <sys/systm.h> 3976166Smarkm#include <sys/lock.h> 4076166Smarkm#include <sys/mutex.h> 4112221Sbde#include <sys/sysproto.h> 421541Srgrimes#include <sys/resourcevar.h> 433308Sphk#include <sys/signalvar.h> 441541Srgrimes#include <sys/kernel.h> 451541Srgrimes#include <sys/systm.h> 4625583Speter#include <sys/sysent.h> 471541Srgrimes#include <sys/proc.h> 4825656Speter#include <sys/time.h> 4958377Sphk#include <sys/timetc.h> 501541Srgrimes#include <sys/vnode.h> 5176166Smarkm 5226335Speter#include <vm/vm.h> 5326335Speter#include <vm/vm_extern.h> 541541Srgrimes 559369Sdgstruct timezone tz; 569369Sdg 578876Srgrimes/* 581541Srgrimes * Time of day and interval timer support. 591541Srgrimes * 601541Srgrimes * These routines provide the kernel entry points to get and set 611541Srgrimes * the time-of-day and per-process interval timers. Subroutines 621541Srgrimes * here provide support for adding and subtracting timeval structures 631541Srgrimes * and decrementing interval timers, optionally reloading the interval 641541Srgrimes * timers when they expire. 651541Srgrimes */ 661541Srgrimes 6792723Salfredstatic int nanosleep1(struct thread *td, struct timespec *rqt, 6892723Salfred struct timespec *rmt); 6994343Sjhbstatic int settime(struct thread *, struct timeval *); 7092723Salfredstatic void timevalfix(struct timeval *); 7192723Salfredstatic void no_lease_updatetime(int); 7213016Sbde 7330739Sphkstatic void 7430739Sphkno_lease_updatetime(deltat) 7530739Sphk int deltat; 7630739Sphk{ 7730739Sphk} 7830739Sphk 7992723Salfredvoid (*lease_updatetime)(int) = no_lease_updatetime; 8030739Sphk 8125583Speterstatic int 8294343Sjhbsettime(td, tv) 8394343Sjhb struct thread *td; 8425583Speter struct timeval *tv; 8525583Speter{ 8645433Snsayer struct timeval delta, tv1, tv2; 8745438Snsayer static struct timeval maxtime, laststep; 8833690Sphk struct timespec ts; 8925583Speter int s; 9025583Speter 9125656Speter s = splclock(); 9233818Sbde microtime(&tv1); 9335029Sphk delta = *tv; 9435029Sphk timevalsub(&delta, &tv1); 9525583Speter 9625583Speter /* 9733818Sbde * If the system is secure, we do not allow the time to be 9845433Snsayer * set to a value earlier than 1 second less than the highest 9945433Snsayer * time we have yet seen. The worst a miscreant can do in 10045433Snsayer * this circumstance is "freeze" time. He couldn't go 10145433Snsayer * back to the past. 10245438Snsayer * 10345438Snsayer * We similarly do not allow the clock to be stepped more 10445438Snsayer * than one second, nor more than once per second. This allows 10545438Snsayer * a miscreant to make the clock march double-time, but no worse. 10625583Speter */ 10794343Sjhb if (securelevel_gt(td->td_ucred, 1) != 0) { 10845433Snsayer if (delta.tv_sec < 0 || delta.tv_usec < 0) { 10945437Smjacob /* 11045438Snsayer * Update maxtime to latest time we've seen. 11145437Smjacob */ 11245437Smjacob if (tv1.tv_sec > maxtime.tv_sec) 11345437Smjacob maxtime = tv1; 11445437Smjacob tv2 = *tv; 11545437Smjacob timevalsub(&tv2, &maxtime); 11645437Smjacob if (tv2.tv_sec < -1) { 11745437Smjacob tv->tv_sec = maxtime.tv_sec - 1; 11845433Snsayer printf("Time adjustment clamped to -1 second\n"); 11945433Snsayer } 12045437Smjacob } else { 12145438Snsayer if (tv1.tv_sec == laststep.tv_sec) { 12245438Snsayer splx(s); 12345438Snsayer return (EPERM); 12445438Snsayer } 12545438Snsayer if (delta.tv_sec > 1) { 12645438Snsayer tv->tv_sec = tv1.tv_sec + 1; 12745438Snsayer printf("Time adjustment clamped to +1 second\n"); 12845438Snsayer } 12945438Snsayer laststep = *tv; 13045433Snsayer } 13133818Sbde } 13233818Sbde 13333690Sphk ts.tv_sec = tv->tv_sec; 13433690Sphk ts.tv_nsec = tv->tv_usec * 1000; 13594343Sjhb mtx_lock(&Giant); 13658377Sphk tc_setclock(&ts); 13725583Speter (void) splsoftclock(); 13825583Speter lease_updatetime(delta.tv_sec); 13925583Speter splx(s); 14025583Speter resettodr(); 14194343Sjhb mtx_unlock(&Giant); 14225583Speter return (0); 14325583Speter} 14425583Speter 14512221Sbde#ifndef _SYS_SYSPROTO_H_ 14625583Speterstruct clock_gettime_args { 14725583Speter clockid_t clock_id; 14825583Speter struct timespec *tp; 14925583Speter}; 15025583Speter#endif 15125656Speter 15282746Sdillon/* 15382746Sdillon * MPSAFE 15482746Sdillon */ 15525583Speter/* ARGSUSED */ 15625583Speterint 15783366Sjulianclock_gettime(td, uap) 15883366Sjulian struct thread *td; 15925583Speter struct clock_gettime_args *uap; 16025583Speter{ 16125583Speter struct timespec ats; 16225583Speter 16325656Speter if (SCARG(uap, clock_id) != CLOCK_REALTIME) 16425583Speter return (EINVAL); 16582746Sdillon mtx_lock(&Giant); 16633690Sphk nanotime(&ats); 16782746Sdillon mtx_unlock(&Giant); 16825656Speter return (copyout(&ats, SCARG(uap, tp), sizeof(ats))); 16925583Speter} 17025583Speter 17125583Speter#ifndef _SYS_SYSPROTO_H_ 17225583Speterstruct clock_settime_args { 17325583Speter clockid_t clock_id; 17425583Speter const struct timespec *tp; 17525583Speter}; 17625583Speter#endif 17725656Speter 17882746Sdillon/* 17982746Sdillon * MPSAFE 18082746Sdillon */ 18125583Speter/* ARGSUSED */ 18225583Speterint 18383366Sjulianclock_settime(td, uap) 18483366Sjulian struct thread *td; 18525583Speter struct clock_settime_args *uap; 18625583Speter{ 18725583Speter struct timeval atv; 18825583Speter struct timespec ats; 18925583Speter int error; 19025583Speter 19193593Sjhb if ((error = suser(td)) != 0) 19294343Sjhb return (error); 19394343Sjhb if (SCARG(uap, clock_id) != CLOCK_REALTIME) 19494343Sjhb return (EINVAL); 19525583Speter if ((error = copyin(SCARG(uap, tp), &ats, sizeof(ats))) != 0) 19694343Sjhb return (error); 19794343Sjhb if (ats.tv_nsec < 0 || ats.tv_nsec >= 1000000000) 19894343Sjhb return (EINVAL); 19934901Sphk /* XXX Don't convert nsec->usec and back */ 20025583Speter TIMESPEC_TO_TIMEVAL(&atv, &ats); 20194343Sjhb error = settime(td, &atv); 20282746Sdillon return (error); 20325583Speter} 20425583Speter 20525583Speter#ifndef _SYS_SYSPROTO_H_ 20625583Speterstruct clock_getres_args { 20725583Speter clockid_t clock_id; 20825583Speter struct timespec *tp; 20925583Speter}; 21025583Speter#endif 21125656Speter 21225583Speterint 21383366Sjulianclock_getres(td, uap) 21483366Sjulian struct thread *td; 21525583Speter struct clock_getres_args *uap; 21625583Speter{ 21725583Speter struct timespec ts; 21825656Speter int error; 21925583Speter 22025656Speter if (SCARG(uap, clock_id) != CLOCK_REALTIME) 22125583Speter return (EINVAL); 22225656Speter error = 0; 22325583Speter if (SCARG(uap, tp)) { 22425583Speter ts.tv_sec = 0; 22595529Sphk ts.tv_nsec = 1000000000 / tc_getfrequency(); 22625656Speter error = copyout(&ts, SCARG(uap, tp), sizeof(ts)); 22725583Speter } 22825656Speter return (error); 22925583Speter} 23025583Speter 23126335Speterstatic int nanowait; 23225656Speter 23326335Speterstatic int 23483366Sjuliannanosleep1(td, rqt, rmt) 23583366Sjulian struct thread *td; 23626335Speter struct timespec *rqt, *rmt; 23725583Speter{ 23835045Sphk struct timespec ts, ts2, ts3; 23935042Sphk struct timeval tv; 24035042Sphk int error; 24125583Speter 24228773Sbde if (rqt->tv_nsec < 0 || rqt->tv_nsec >= 1000000000) 24325656Speter return (EINVAL); 24443301Sdillon if (rqt->tv_sec < 0 || (rqt->tv_sec == 0 && rqt->tv_nsec == 0)) 24528773Sbde return (0); 24636119Sphk getnanouptime(&ts); 24735029Sphk timespecadd(&ts, rqt); 24835042Sphk TIMESPEC_TO_TIMEVAL(&tv, rqt); 24935042Sphk for (;;) { 25035042Sphk error = tsleep(&nanowait, PWAIT | PCATCH, "nanslp", 25135042Sphk tvtohz(&tv)); 25236119Sphk getnanouptime(&ts2); 25335042Sphk if (error != EWOULDBLOCK) { 25435042Sphk if (error == ERESTART) 25535042Sphk error = EINTR; 25635042Sphk if (rmt != NULL) { 25735042Sphk timespecsub(&ts, &ts2); 25835042Sphk if (ts.tv_sec < 0) 25935042Sphk timespecclear(&ts); 26035042Sphk *rmt = ts; 26135042Sphk } 26235042Sphk return (error); 26335042Sphk } 26435029Sphk if (timespeccmp(&ts2, &ts, >=)) 26535042Sphk return (0); 26635045Sphk ts3 = ts; 26735045Sphk timespecsub(&ts3, &ts2); 26835045Sphk TIMESPEC_TO_TIMEVAL(&tv, &ts3); 26926335Speter } 27026335Speter} 27125583Speter 27226335Speter#ifndef _SYS_SYSPROTO_H_ 27326335Speterstruct nanosleep_args { 27426335Speter struct timespec *rqtp; 27526335Speter struct timespec *rmtp; 27626335Speter}; 27726335Speter#endif 27826335Speter 27982746Sdillon/* 28082746Sdillon * MPSAFE 28182746Sdillon */ 28226335Speter/* ARGSUSED */ 28326335Speterint 28483366Sjuliannanosleep(td, uap) 28583366Sjulian struct thread *td; 28626335Speter struct nanosleep_args *uap; 28726335Speter{ 28826335Speter struct timespec rmt, rqt; 28982746Sdillon int error; 29026335Speter 29126335Speter error = copyin(SCARG(uap, rqtp), &rqt, sizeof(rqt)); 29226335Speter if (error) 29326335Speter return (error); 29482746Sdillon 29582746Sdillon mtx_lock(&Giant); 29682746Sdillon if (SCARG(uap, rmtp)) { 29752644Sphk if (!useracc((caddr_t)SCARG(uap, rmtp), sizeof(rmt), 29882746Sdillon VM_PROT_WRITE)) { 29982746Sdillon error = EFAULT; 30082746Sdillon goto done2; 30182746Sdillon } 30282746Sdillon } 30383366Sjulian error = nanosleep1(td, &rqt, &rmt); 30435043Speter if (error && SCARG(uap, rmtp)) { 30582746Sdillon int error2; 30682746Sdillon 30725656Speter error2 = copyout(&rmt, SCARG(uap, rmtp), sizeof(rmt)); 30826335Speter if (error2) /* XXX shouldn't happen, did useracc() above */ 30982746Sdillon error = error2; 31025583Speter } 31182746Sdillondone2: 31282746Sdillon mtx_unlock(&Giant); 31325656Speter return (error); 31425583Speter} 31525583Speter 31626335Speter#ifndef _SYS_SYSPROTO_H_ 3171541Srgrimesstruct gettimeofday_args { 3181541Srgrimes struct timeval *tp; 3191541Srgrimes struct timezone *tzp; 3201541Srgrimes}; 32112221Sbde#endif 32282746Sdillon/* 32382746Sdillon * MPSAFE 32482746Sdillon */ 3251541Srgrimes/* ARGSUSED */ 3261549Srgrimesint 32783366Sjuliangettimeofday(td, uap) 32883366Sjulian struct thread *td; 3291541Srgrimes register struct gettimeofday_args *uap; 3301541Srgrimes{ 3311541Srgrimes struct timeval atv; 3321541Srgrimes int error = 0; 3331541Srgrimes 3341541Srgrimes if (uap->tp) { 3351541Srgrimes microtime(&atv); 33699012Salfred error = copyout(&atv, uap->tp, sizeof (atv)); 3371541Srgrimes } 33890836Sphk if (error == 0 && uap->tzp != NULL) { 33990836Sphk mtx_lock(&Giant); 34099012Salfred error = copyout(&tz, uap->tzp, sizeof (tz)); 34190836Sphk mtx_unlock(&Giant); 34282746Sdillon } 3431541Srgrimes return (error); 3441541Srgrimes} 3451541Srgrimes 34612221Sbde#ifndef _SYS_SYSPROTO_H_ 3471541Srgrimesstruct settimeofday_args { 3481541Srgrimes struct timeval *tv; 3491541Srgrimes struct timezone *tzp; 3501541Srgrimes}; 35112221Sbde#endif 35282746Sdillon/* 35382746Sdillon * MPSAFE 35482746Sdillon */ 3551541Srgrimes/* ARGSUSED */ 3561549Srgrimesint 35783366Sjuliansettimeofday(td, uap) 35883366Sjulian struct thread *td; 3591541Srgrimes struct settimeofday_args *uap; 3601541Srgrimes{ 36125656Speter struct timeval atv; 3621541Srgrimes struct timezone atz; 36382746Sdillon int error = 0; 3641541Srgrimes 36593593Sjhb if ((error = suser(td))) 36694343Sjhb return (error); 3671541Srgrimes /* Verify all parameters before changing time. */ 36825656Speter if (uap->tv) { 36999012Salfred if ((error = copyin(uap->tv, &atv, sizeof(atv)))) 37094343Sjhb return (error); 37194343Sjhb if (atv.tv_usec < 0 || atv.tv_usec >= 1000000) 37294343Sjhb return (EINVAL); 37325656Speter } 3741541Srgrimes if (uap->tzp && 37599012Salfred (error = copyin(uap->tzp, &atz, sizeof(atz)))) 37694343Sjhb return (error); 37794343Sjhb 37894343Sjhb if (uap->tv && (error = settime(td, &atv))) 37994343Sjhb return (error); 38094343Sjhb if (uap->tzp) { 38194343Sjhb mtx_lock(&Giant); 38294343Sjhb tz = atz; 38394343Sjhb mtx_unlock(&Giant); 38482746Sdillon } 38582746Sdillon return (error); 3861541Srgrimes} 38782746Sdillon/* 3881541Srgrimes * Get value of an interval timer. The process virtual and 3891541Srgrimes * profiling virtual time timers are kept in the p_stats area, since 3901541Srgrimes * they can be swapped out. These are kept internally in the 3911541Srgrimes * way they are specified externally: in time until they expire. 3921541Srgrimes * 3931541Srgrimes * The real time interval timer is kept in the process table slot 3941541Srgrimes * for the process, and its value (it_value) is kept as an 3951541Srgrimes * absolute time rather than as a delta, so that it is easy to keep 3961541Srgrimes * periodic real-time signals from drifting. 3971541Srgrimes * 3981541Srgrimes * Virtual time timers are processed in the hardclock() routine of 3991541Srgrimes * kern_clock.c. The real time timer is processed by a timeout 4001541Srgrimes * routine, called from the softclock() routine. Since a callout 4011541Srgrimes * may be delayed in real time due to interrupt processing in the system, 4021541Srgrimes * it is possible for the real time timeout routine (realitexpire, given below), 4031541Srgrimes * to be delayed in real time past when it is supposed to occur. It 4041541Srgrimes * does not suffice, therefore, to reload the real timer .it_value from the 4051541Srgrimes * real time timers .it_interval. Rather, we compute the next time in 4061541Srgrimes * absolute time the timer should go off. 4071541Srgrimes */ 40812221Sbde#ifndef _SYS_SYSPROTO_H_ 4091541Srgrimesstruct getitimer_args { 4101541Srgrimes u_int which; 4111541Srgrimes struct itimerval *itv; 4121541Srgrimes}; 41312221Sbde#endif 41482746Sdillon/* 41582746Sdillon * MPSAFE 41682746Sdillon */ 4171541Srgrimes/* ARGSUSED */ 4181549Srgrimesint 41983366Sjuliangetitimer(td, uap) 42083366Sjulian struct thread *td; 4211541Srgrimes register struct getitimer_args *uap; 4221541Srgrimes{ 42383366Sjulian struct proc *p = td->td_proc; 42434961Sphk struct timeval ctv; 4251541Srgrimes struct itimerval aitv; 4261541Srgrimes int s; 42782746Sdillon int error; 4281541Srgrimes 4291541Srgrimes if (uap->which > ITIMER_PROF) 4301541Srgrimes return (EINVAL); 43182746Sdillon 43282746Sdillon mtx_lock(&Giant); 43382746Sdillon 43434961Sphk s = splclock(); /* XXX still needed ? */ 4351541Srgrimes if (uap->which == ITIMER_REAL) { 4361541Srgrimes /* 43736128Sbde * Convert from absolute to relative time in .it_value 4381541Srgrimes * part of real time timer. If time for real time timer 4391541Srgrimes * has passed return 0, else return difference between 4401541Srgrimes * current time and time for the timer to go off. 4411541Srgrimes */ 4421541Srgrimes aitv = p->p_realtimer; 44335058Sphk if (timevalisset(&aitv.it_value)) { 44436119Sphk getmicrouptime(&ctv); 44535058Sphk if (timevalcmp(&aitv.it_value, &ctv, <)) 44635058Sphk timevalclear(&aitv.it_value); 4471541Srgrimes else 44834961Sphk timevalsub(&aitv.it_value, &ctv); 44934961Sphk } 45082746Sdillon } else { 4511541Srgrimes aitv = p->p_stats->p_timer[uap->which]; 45282746Sdillon } 4531541Srgrimes splx(s); 45499012Salfred error = copyout(&aitv, uap->itv, sizeof (struct itimerval)); 45582746Sdillon mtx_unlock(&Giant); 45682746Sdillon return(error); 4571541Srgrimes} 4581541Srgrimes 45912221Sbde#ifndef _SYS_SYSPROTO_H_ 4601541Srgrimesstruct setitimer_args { 4611541Srgrimes u_int which; 4621541Srgrimes struct itimerval *itv, *oitv; 4631541Srgrimes}; 46412221Sbde#endif 46582746Sdillon/* 46682746Sdillon * MPSAFE 46782746Sdillon */ 4681541Srgrimes/* ARGSUSED */ 4691549Srgrimesint 47083366Sjuliansetitimer(td, uap) 47183366Sjulian struct thread *td; 4721541Srgrimes register struct setitimer_args *uap; 4731541Srgrimes{ 47483366Sjulian struct proc *p = td->td_proc; 4751541Srgrimes struct itimerval aitv; 47634961Sphk struct timeval ctv; 4771541Srgrimes register struct itimerval *itvp; 47882746Sdillon int s, error = 0; 4791541Srgrimes 4801541Srgrimes if (uap->which > ITIMER_PROF) 4811541Srgrimes return (EINVAL); 4821541Srgrimes itvp = uap->itv; 48399012Salfred if (itvp && (error = copyin(itvp, &aitv, sizeof(struct itimerval)))) 4841541Srgrimes return (error); 48582746Sdillon 48682746Sdillon mtx_lock(&Giant); 48782746Sdillon 48812381Sbde if ((uap->itv = uap->oitv) && 48983366Sjulian (error = getitimer(td, (struct getitimer_args *)uap))) { 49082746Sdillon goto done2; 49182746Sdillon } 49282746Sdillon if (itvp == 0) { 49382746Sdillon error = 0; 49482746Sdillon goto done2; 49582746Sdillon } 49682746Sdillon if (itimerfix(&aitv.it_value)) { 49782746Sdillon error = EINVAL; 49882746Sdillon goto done2; 49982746Sdillon } 50082746Sdillon if (!timevalisset(&aitv.it_value)) { 50135058Sphk timevalclear(&aitv.it_interval); 50282746Sdillon } else if (itimerfix(&aitv.it_interval)) { 50382746Sdillon error = EINVAL; 50482746Sdillon goto done2; 50582746Sdillon } 50634961Sphk s = splclock(); /* XXX: still needed ? */ 5071541Srgrimes if (uap->which == ITIMER_REAL) { 50835058Sphk if (timevalisset(&p->p_realtimer.it_value)) 50969286Sjake callout_stop(&p->p_itcallout); 51035058Sphk if (timevalisset(&aitv.it_value)) 51169286Sjake callout_reset(&p->p_itcallout, tvtohz(&aitv.it_value), 51269286Sjake realitexpire, p); 51336119Sphk getmicrouptime(&ctv); 51435044Sphk timevaladd(&aitv.it_value, &ctv); 5151541Srgrimes p->p_realtimer = aitv; 51682746Sdillon } else { 5171541Srgrimes p->p_stats->p_timer[uap->which] = aitv; 51882746Sdillon } 5191541Srgrimes splx(s); 52082746Sdillondone2: 52182746Sdillon mtx_unlock(&Giant); 52282746Sdillon return (error); 5231541Srgrimes} 5241541Srgrimes 5251541Srgrimes/* 5261541Srgrimes * Real interval timer expired: 5271541Srgrimes * send process whose timer expired an alarm signal. 5281541Srgrimes * If time is not set up to reload, then just return. 5291541Srgrimes * Else compute next time timer should go off which is > current time. 5301541Srgrimes * This is where delay in processing this timeout causes multiple 5311541Srgrimes * SIGALRM calls to be compressed into one. 53236127Sbde * tvtohz() always adds 1 to allow for the time until the next clock 5339327Sbde * interrupt being strictly less than 1 clock tick, but we don't want 5349327Sbde * that here since we want to appear to be in sync with the clock 5359327Sbde * interrupt even when we're delayed. 5361541Srgrimes */ 5371541Srgrimesvoid 5381541Srgrimesrealitexpire(arg) 5391541Srgrimes void *arg; 5401541Srgrimes{ 5411541Srgrimes register struct proc *p; 54235044Sphk struct timeval ctv, ntv; 5431541Srgrimes int s; 5441541Srgrimes 5451541Srgrimes p = (struct proc *)arg; 54673916Sjhb PROC_LOCK(p); 5471541Srgrimes psignal(p, SIGALRM); 54835058Sphk if (!timevalisset(&p->p_realtimer.it_interval)) { 54935058Sphk timevalclear(&p->p_realtimer.it_value); 55073916Sjhb PROC_UNLOCK(p); 5511541Srgrimes return; 5521541Srgrimes } 5531541Srgrimes for (;;) { 55434961Sphk s = splclock(); /* XXX: still neeeded ? */ 5551541Srgrimes timevaladd(&p->p_realtimer.it_value, 5561541Srgrimes &p->p_realtimer.it_interval); 55736119Sphk getmicrouptime(&ctv); 55835058Sphk if (timevalcmp(&p->p_realtimer.it_value, &ctv, >)) { 55935044Sphk ntv = p->p_realtimer.it_value; 56035044Sphk timevalsub(&ntv, &ctv); 56169286Sjake callout_reset(&p->p_itcallout, tvtohz(&ntv) - 1, 56269286Sjake realitexpire, p); 5631541Srgrimes splx(s); 56473916Sjhb PROC_UNLOCK(p); 5651541Srgrimes return; 5661541Srgrimes } 5671541Srgrimes splx(s); 5681541Srgrimes } 56973916Sjhb /*NOTREACHED*/ 5701541Srgrimes} 5711541Srgrimes 5721541Srgrimes/* 5731541Srgrimes * Check that a proposed value to load into the .it_value or 5741541Srgrimes * .it_interval part of an interval timer is acceptable, and 5751541Srgrimes * fix it to have at least minimal value (i.e. if it is less 5761541Srgrimes * than the resolution of the clock, round it up.) 5771541Srgrimes */ 5781549Srgrimesint 5791541Srgrimesitimerfix(tv) 5801541Srgrimes struct timeval *tv; 5811541Srgrimes{ 5821541Srgrimes 5831541Srgrimes if (tv->tv_sec < 0 || tv->tv_sec > 100000000 || 5841541Srgrimes tv->tv_usec < 0 || tv->tv_usec >= 1000000) 5851541Srgrimes return (EINVAL); 5861541Srgrimes if (tv->tv_sec == 0 && tv->tv_usec != 0 && tv->tv_usec < tick) 5871541Srgrimes tv->tv_usec = tick; 5881541Srgrimes return (0); 5891541Srgrimes} 5901541Srgrimes 5911541Srgrimes/* 5921541Srgrimes * Decrement an interval timer by a specified number 5931541Srgrimes * of microseconds, which must be less than a second, 5941541Srgrimes * i.e. < 1000000. If the timer expires, then reload 5951541Srgrimes * it. In this case, carry over (usec - old value) to 5961541Srgrimes * reduce the value reloaded into the timer so that 5971541Srgrimes * the timer does not drift. This routine assumes 5981541Srgrimes * that it is called in a context where the timers 5991541Srgrimes * on which it is operating cannot change in value. 6001541Srgrimes */ 6011549Srgrimesint 6021541Srgrimesitimerdecr(itp, usec) 6031541Srgrimes register struct itimerval *itp; 6041541Srgrimes int usec; 6051541Srgrimes{ 6061541Srgrimes 6071541Srgrimes if (itp->it_value.tv_usec < usec) { 6081541Srgrimes if (itp->it_value.tv_sec == 0) { 6091541Srgrimes /* expired, and already in next interval */ 6101541Srgrimes usec -= itp->it_value.tv_usec; 6111541Srgrimes goto expire; 6121541Srgrimes } 6131541Srgrimes itp->it_value.tv_usec += 1000000; 6141541Srgrimes itp->it_value.tv_sec--; 6151541Srgrimes } 6161541Srgrimes itp->it_value.tv_usec -= usec; 6171541Srgrimes usec = 0; 61835058Sphk if (timevalisset(&itp->it_value)) 6191541Srgrimes return (1); 6201541Srgrimes /* expired, exactly at end of interval */ 6211541Srgrimesexpire: 62235058Sphk if (timevalisset(&itp->it_interval)) { 6231541Srgrimes itp->it_value = itp->it_interval; 6241541Srgrimes itp->it_value.tv_usec -= usec; 6251541Srgrimes if (itp->it_value.tv_usec < 0) { 6261541Srgrimes itp->it_value.tv_usec += 1000000; 6271541Srgrimes itp->it_value.tv_sec--; 6281541Srgrimes } 6291541Srgrimes } else 6301541Srgrimes itp->it_value.tv_usec = 0; /* sec is already 0 */ 6311541Srgrimes return (0); 6321541Srgrimes} 6331541Srgrimes 6341541Srgrimes/* 6351541Srgrimes * Add and subtract routines for timevals. 6361541Srgrimes * N.B.: subtract routine doesn't deal with 6371541Srgrimes * results which are before the beginning, 6381541Srgrimes * it just gets very confused in this case. 6391541Srgrimes * Caveat emptor. 6401541Srgrimes */ 6411549Srgrimesvoid 6421541Srgrimestimevaladd(t1, t2) 6431541Srgrimes struct timeval *t1, *t2; 6441541Srgrimes{ 6451541Srgrimes 6461541Srgrimes t1->tv_sec += t2->tv_sec; 6471541Srgrimes t1->tv_usec += t2->tv_usec; 6481541Srgrimes timevalfix(t1); 6491541Srgrimes} 6501541Srgrimes 6511549Srgrimesvoid 6521541Srgrimestimevalsub(t1, t2) 6531541Srgrimes struct timeval *t1, *t2; 6541541Srgrimes{ 6551541Srgrimes 6561541Srgrimes t1->tv_sec -= t2->tv_sec; 6571541Srgrimes t1->tv_usec -= t2->tv_usec; 6581541Srgrimes timevalfix(t1); 6591541Srgrimes} 6601541Srgrimes 66112819Sphkstatic void 6621541Srgrimestimevalfix(t1) 6631541Srgrimes struct timeval *t1; 6641541Srgrimes{ 6651541Srgrimes 6661541Srgrimes if (t1->tv_usec < 0) { 6671541Srgrimes t1->tv_sec--; 6681541Srgrimes t1->tv_usec += 1000000; 6691541Srgrimes } 6701541Srgrimes if (t1->tv_usec >= 1000000) { 6711541Srgrimes t1->tv_sec++; 6721541Srgrimes t1->tv_usec -= 1000000; 6731541Srgrimes } 6741541Srgrimes} 675