kern_time.c revision 36128
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 3436128Sbde * $Id: kern_time.c,v 1.56 1998/05/17 20:08:04 bde Exp $ 351541Srgrimes */ 361541Srgrimes 371541Srgrimes#include <sys/param.h> 3812221Sbde#include <sys/sysproto.h> 391541Srgrimes#include <sys/resourcevar.h> 403308Sphk#include <sys/signalvar.h> 411541Srgrimes#include <sys/kernel.h> 421541Srgrimes#include <sys/systm.h> 4325583Speter#include <sys/sysent.h> 441541Srgrimes#include <sys/proc.h> 4525656Speter#include <sys/time.h> 461541Srgrimes#include <sys/vnode.h> 4726335Speter#include <vm/vm.h> 4826335Speter#include <vm/vm_extern.h> 491541Srgrimes 509369Sdgstruct timezone tz; 519369Sdg 528876Srgrimes/* 531541Srgrimes * Time of day and interval timer support. 541541Srgrimes * 551541Srgrimes * These routines provide the kernel entry points to get and set 561541Srgrimes * the time-of-day and per-process interval timers. Subroutines 571541Srgrimes * here provide support for adding and subtracting timeval structures 581541Srgrimes * and decrementing interval timers, optionally reloading the interval 591541Srgrimes * timers when they expire. 601541Srgrimes */ 611541Srgrimes 6228773Sbdestatic int nanosleep1 __P((struct proc *p, struct timespec *rqt, 6328773Sbde struct timespec *rmt)); 6425656Speterstatic int settime __P((struct timeval *)); 6513016Sbdestatic void timevalfix __P((struct timeval *)); 6630994Sphkstatic void no_lease_updatetime __P((int)); 6713016Sbde 6830739Sphkstatic void 6930739Sphkno_lease_updatetime(deltat) 7030739Sphk int deltat; 7130739Sphk{ 7230739Sphk} 7330739Sphk 7430739Sphkvoid (*lease_updatetime) __P((int)) = no_lease_updatetime; 7530739Sphk 7625583Speterstatic int 7725583Spetersettime(tv) 7825583Speter struct timeval *tv; 7925583Speter{ 8033818Sbde struct timeval delta, tv1; 8133690Sphk struct timespec ts; 8225583Speter struct proc *p; 8325583Speter int s; 8425583Speter 8525656Speter s = splclock(); 8633818Sbde microtime(&tv1); 8735029Sphk delta = *tv; 8835029Sphk timevalsub(&delta, &tv1); 8925583Speter 9025583Speter /* 9133818Sbde * If the system is secure, we do not allow the time to be 9233818Sbde * set to an earlier value (it may be slowed using adjtime, 9333818Sbde * but not set back). This feature prevent interlopers from 9433818Sbde * setting arbitrary time stamps on files. 9525583Speter */ 9633818Sbde if (delta.tv_sec < 0 && securelevel > 1) { 9733818Sbde splx(s); 9833818Sbde return (EPERM); 9933818Sbde } 10033818Sbde 10133690Sphk ts.tv_sec = tv->tv_sec; 10233690Sphk ts.tv_nsec = tv->tv_usec * 1000; 10333690Sphk set_timecounter(&ts); 10425583Speter (void) splsoftclock(); 10525583Speter lease_updatetime(delta.tv_sec); 10625583Speter splx(s); 10725583Speter resettodr(); 10825583Speter return (0); 10925583Speter} 11025583Speter 11112221Sbde#ifndef _SYS_SYSPROTO_H_ 11225583Speterstruct clock_gettime_args { 11325583Speter clockid_t clock_id; 11425583Speter struct timespec *tp; 11525583Speter}; 11625583Speter#endif 11725656Speter 11825583Speter/* ARGSUSED */ 11925583Speterint 12030994Sphkclock_gettime(p, uap) 12125583Speter struct proc *p; 12225583Speter struct clock_gettime_args *uap; 12325583Speter{ 12425583Speter struct timespec ats; 12525583Speter 12625656Speter if (SCARG(uap, clock_id) != CLOCK_REALTIME) 12725583Speter return (EINVAL); 12833690Sphk nanotime(&ats); 12925656Speter return (copyout(&ats, SCARG(uap, tp), sizeof(ats))); 13025583Speter} 13125583Speter 13225583Speter#ifndef _SYS_SYSPROTO_H_ 13325583Speterstruct clock_settime_args { 13425583Speter clockid_t clock_id; 13525583Speter const struct timespec *tp; 13625583Speter}; 13725583Speter#endif 13825656Speter 13925583Speter/* ARGSUSED */ 14025583Speterint 14130994Sphkclock_settime(p, uap) 14225583Speter struct proc *p; 14325583Speter struct clock_settime_args *uap; 14425583Speter{ 14525583Speter struct timeval atv; 14625583Speter struct timespec ats; 14725583Speter int error; 14825583Speter 14925583Speter if ((error = suser(p->p_ucred, &p->p_acflag)) != 0) 15025583Speter return (error); 15125656Speter if (SCARG(uap, clock_id) != CLOCK_REALTIME) 15225583Speter return (EINVAL); 15325583Speter if ((error = copyin(SCARG(uap, tp), &ats, sizeof(ats))) != 0) 15425583Speter return (error); 15527855Sbde if (ats.tv_nsec < 0 || ats.tv_nsec >= 1000000000) 15625656Speter return (EINVAL); 15734901Sphk /* XXX Don't convert nsec->usec and back */ 15825583Speter TIMESPEC_TO_TIMEVAL(&atv, &ats); 15925583Speter if ((error = settime(&atv))) 16025583Speter return (error); 16125656Speter return (0); 16225583Speter} 16325583Speter 16425583Speter#ifndef _SYS_SYSPROTO_H_ 16525583Speterstruct clock_getres_args { 16625583Speter clockid_t clock_id; 16725583Speter struct timespec *tp; 16825583Speter}; 16925583Speter#endif 17025656Speter 17125583Speterint 17230994Sphkclock_getres(p, uap) 17325583Speter struct proc *p; 17425583Speter struct clock_getres_args *uap; 17525583Speter{ 17625583Speter struct timespec ts; 17725656Speter int error; 17825583Speter 17925656Speter if (SCARG(uap, clock_id) != CLOCK_REALTIME) 18025583Speter return (EINVAL); 18125656Speter error = 0; 18225583Speter if (SCARG(uap, tp)) { 18325583Speter ts.tv_sec = 0; 18433690Sphk ts.tv_nsec = 1000000000 / timecounter->frequency; 18525656Speter error = copyout(&ts, SCARG(uap, tp), sizeof(ts)); 18625583Speter } 18725656Speter return (error); 18825583Speter} 18925583Speter 19026335Speterstatic int nanowait; 19125656Speter 19226335Speterstatic int 19326335Speternanosleep1(p, rqt, rmt) 19425583Speter struct proc *p; 19526335Speter struct timespec *rqt, *rmt; 19625583Speter{ 19735045Sphk struct timespec ts, ts2, ts3; 19835042Sphk struct timeval tv; 19935042Sphk int error; 20025583Speter 20128773Sbde if (rqt->tv_nsec < 0 || rqt->tv_nsec >= 1000000000) 20225656Speter return (EINVAL); 20328773Sbde if (rqt->tv_sec < 0 || rqt->tv_sec == 0 && rqt->tv_nsec == 0) 20428773Sbde return (0); 20536119Sphk getnanouptime(&ts); 20635029Sphk timespecadd(&ts, rqt); 20735042Sphk TIMESPEC_TO_TIMEVAL(&tv, rqt); 20835042Sphk for (;;) { 20935042Sphk error = tsleep(&nanowait, PWAIT | PCATCH, "nanslp", 21035042Sphk tvtohz(&tv)); 21136119Sphk getnanouptime(&ts2); 21235042Sphk if (error != EWOULDBLOCK) { 21335042Sphk if (error == ERESTART) 21435042Sphk error = EINTR; 21535042Sphk if (rmt != NULL) { 21635042Sphk timespecsub(&ts, &ts2); 21735042Sphk if (ts.tv_sec < 0) 21835042Sphk timespecclear(&ts); 21935042Sphk *rmt = ts; 22035042Sphk } 22135042Sphk return (error); 22235042Sphk } 22335029Sphk if (timespeccmp(&ts2, &ts, >=)) 22435042Sphk return (0); 22535045Sphk ts3 = ts; 22635045Sphk timespecsub(&ts3, &ts2); 22735045Sphk TIMESPEC_TO_TIMEVAL(&tv, &ts3); 22826335Speter } 22926335Speter} 23025583Speter 23126335Speter#ifndef _SYS_SYSPROTO_H_ 23226335Speterstruct nanosleep_args { 23326335Speter struct timespec *rqtp; 23426335Speter struct timespec *rmtp; 23526335Speter}; 23626335Speter#endif 23726335Speter 23826335Speter/* ARGSUSED */ 23926335Speterint 24030994Sphknanosleep(p, uap) 24126335Speter struct proc *p; 24226335Speter struct nanosleep_args *uap; 24326335Speter{ 24426335Speter struct timespec rmt, rqt; 24526335Speter int error, error2; 24626335Speter 24726335Speter error = copyin(SCARG(uap, rqtp), &rqt, sizeof(rqt)); 24826335Speter if (error) 24926335Speter return (error); 25026336Speter if (SCARG(uap, rmtp)) 25126336Speter if (!useracc((caddr_t)SCARG(uap, rmtp), sizeof(rmt), B_WRITE)) 25226336Speter return (EFAULT); 25326335Speter error = nanosleep1(p, &rqt, &rmt); 25435043Speter if (error && SCARG(uap, rmtp)) { 25525656Speter error2 = copyout(&rmt, SCARG(uap, rmtp), sizeof(rmt)); 25626335Speter if (error2) /* XXX shouldn't happen, did useracc() above */ 25725656Speter return (error2); 25825583Speter } 25925656Speter return (error); 26025583Speter} 26125583Speter 26226335Speter#ifndef _SYS_SYSPROTO_H_ 2631541Srgrimesstruct gettimeofday_args { 2641541Srgrimes struct timeval *tp; 2651541Srgrimes struct timezone *tzp; 2661541Srgrimes}; 26712221Sbde#endif 2681541Srgrimes/* ARGSUSED */ 2691549Srgrimesint 27030994Sphkgettimeofday(p, uap) 2711541Srgrimes struct proc *p; 2721541Srgrimes register struct gettimeofday_args *uap; 2731541Srgrimes{ 2741541Srgrimes struct timeval atv; 2751541Srgrimes int error = 0; 2761541Srgrimes 2771541Srgrimes if (uap->tp) { 2781541Srgrimes microtime(&atv); 2793098Sphk if ((error = copyout((caddr_t)&atv, (caddr_t)uap->tp, 2803098Sphk sizeof (atv)))) 2811541Srgrimes return (error); 2821541Srgrimes } 2831541Srgrimes if (uap->tzp) 2841541Srgrimes error = copyout((caddr_t)&tz, (caddr_t)uap->tzp, 2851541Srgrimes sizeof (tz)); 2861541Srgrimes return (error); 2871541Srgrimes} 2881541Srgrimes 28912221Sbde#ifndef _SYS_SYSPROTO_H_ 2901541Srgrimesstruct settimeofday_args { 2911541Srgrimes struct timeval *tv; 2921541Srgrimes struct timezone *tzp; 2931541Srgrimes}; 29412221Sbde#endif 2951541Srgrimes/* ARGSUSED */ 2961549Srgrimesint 29730994Sphksettimeofday(p, uap) 2981541Srgrimes struct proc *p; 2991541Srgrimes struct settimeofday_args *uap; 3001541Srgrimes{ 30125656Speter struct timeval atv; 3021541Srgrimes struct timezone atz; 30325656Speter int error; 3041541Srgrimes 3053098Sphk if ((error = suser(p->p_ucred, &p->p_acflag))) 3061541Srgrimes return (error); 3071541Srgrimes /* Verify all parameters before changing time. */ 30825656Speter if (uap->tv) { 30925656Speter if ((error = copyin((caddr_t)uap->tv, (caddr_t)&atv, 31025656Speter sizeof(atv)))) 31125656Speter return (error); 31225656Speter if (atv.tv_usec < 0 || atv.tv_usec >= 1000000) 31325656Speter return (EINVAL); 31425656Speter } 3151541Srgrimes if (uap->tzp && 3161541Srgrimes (error = copyin((caddr_t)uap->tzp, (caddr_t)&atz, sizeof(atz)))) 3171541Srgrimes return (error); 31825583Speter if (uap->tv && (error = settime(&atv))) 31925583Speter return (error); 3201541Srgrimes if (uap->tzp) 3211541Srgrimes tz = atz; 3221541Srgrimes return (0); 3231541Srgrimes} 3241541Srgrimes 3251541Srgrimesint tickdelta; /* current clock skew, us. per tick */ 3261541Srgrimeslong timedelta; /* unapplied time correction, us. */ 32712819Sphkstatic long bigadj = 1000000; /* use 10x skew above bigadj us. */ 3281541Srgrimes 32912221Sbde#ifndef _SYS_SYSPROTO_H_ 3301541Srgrimesstruct adjtime_args { 3311541Srgrimes struct timeval *delta; 3321541Srgrimes struct timeval *olddelta; 3331541Srgrimes}; 33412221Sbde#endif 3351541Srgrimes/* ARGSUSED */ 3361549Srgrimesint 33730994Sphkadjtime(p, uap) 3381541Srgrimes struct proc *p; 3391541Srgrimes register struct adjtime_args *uap; 3401541Srgrimes{ 3411541Srgrimes struct timeval atv; 3421541Srgrimes register long ndelta, ntickdelta, odelta; 3431541Srgrimes int s, error; 3441541Srgrimes 3453098Sphk if ((error = suser(p->p_ucred, &p->p_acflag))) 3461541Srgrimes return (error); 3473098Sphk if ((error = 3483098Sphk copyin((caddr_t)uap->delta, (caddr_t)&atv, sizeof(struct timeval)))) 3491541Srgrimes return (error); 3501541Srgrimes 3511541Srgrimes /* 3521541Srgrimes * Compute the total correction and the rate at which to apply it. 3531541Srgrimes * Round the adjustment down to a whole multiple of the per-tick 3541541Srgrimes * delta, so that after some number of incremental changes in 3551541Srgrimes * hardclock(), tickdelta will become zero, lest the correction 3561541Srgrimes * overshoot and start taking us away from the desired final time. 3571541Srgrimes */ 3581541Srgrimes ndelta = atv.tv_sec * 1000000 + atv.tv_usec; 35917123Sbde if (ndelta > bigadj || ndelta < -bigadj) 3601541Srgrimes ntickdelta = 10 * tickadj; 3611541Srgrimes else 3621541Srgrimes ntickdelta = tickadj; 3631541Srgrimes if (ndelta % ntickdelta) 3641541Srgrimes ndelta = ndelta / ntickdelta * ntickdelta; 3651541Srgrimes 3661541Srgrimes /* 3671541Srgrimes * To make hardclock()'s job easier, make the per-tick delta negative 3681541Srgrimes * if we want time to run slower; then hardclock can simply compute 3691541Srgrimes * tick + tickdelta, and subtract tickdelta from timedelta. 3701541Srgrimes */ 3711541Srgrimes if (ndelta < 0) 3721541Srgrimes ntickdelta = -ntickdelta; 3731541Srgrimes s = splclock(); 3741541Srgrimes odelta = timedelta; 3751541Srgrimes timedelta = ndelta; 3761541Srgrimes tickdelta = ntickdelta; 3771541Srgrimes splx(s); 3781541Srgrimes 3791541Srgrimes if (uap->olddelta) { 3801541Srgrimes atv.tv_sec = odelta / 1000000; 3811541Srgrimes atv.tv_usec = odelta % 1000000; 3821541Srgrimes (void) copyout((caddr_t)&atv, (caddr_t)uap->olddelta, 3831541Srgrimes sizeof(struct timeval)); 3841541Srgrimes } 3851541Srgrimes return (0); 3861541Srgrimes} 3871541Srgrimes 3881541Srgrimes/* 3891541Srgrimes * Get value of an interval timer. The process virtual and 3901541Srgrimes * profiling virtual time timers are kept in the p_stats area, since 3911541Srgrimes * they can be swapped out. These are kept internally in the 3921541Srgrimes * way they are specified externally: in time until they expire. 3931541Srgrimes * 3941541Srgrimes * The real time interval timer is kept in the process table slot 3951541Srgrimes * for the process, and its value (it_value) is kept as an 3961541Srgrimes * absolute time rather than as a delta, so that it is easy to keep 3971541Srgrimes * periodic real-time signals from drifting. 3981541Srgrimes * 3991541Srgrimes * Virtual time timers are processed in the hardclock() routine of 4001541Srgrimes * kern_clock.c. The real time timer is processed by a timeout 4011541Srgrimes * routine, called from the softclock() routine. Since a callout 4021541Srgrimes * may be delayed in real time due to interrupt processing in the system, 4031541Srgrimes * it is possible for the real time timeout routine (realitexpire, given below), 4041541Srgrimes * to be delayed in real time past when it is supposed to occur. It 4051541Srgrimes * does not suffice, therefore, to reload the real timer .it_value from the 4061541Srgrimes * real time timers .it_interval. Rather, we compute the next time in 4071541Srgrimes * absolute time the timer should go off. 4081541Srgrimes */ 40912221Sbde#ifndef _SYS_SYSPROTO_H_ 4101541Srgrimesstruct getitimer_args { 4111541Srgrimes u_int which; 4121541Srgrimes struct itimerval *itv; 4131541Srgrimes}; 41412221Sbde#endif 4151541Srgrimes/* ARGSUSED */ 4161549Srgrimesint 41730994Sphkgetitimer(p, uap) 4181541Srgrimes struct proc *p; 4191541Srgrimes register struct getitimer_args *uap; 4201541Srgrimes{ 42134961Sphk struct timeval ctv; 4221541Srgrimes struct itimerval aitv; 4231541Srgrimes int s; 4241541Srgrimes 4251541Srgrimes if (uap->which > ITIMER_PROF) 4261541Srgrimes return (EINVAL); 42734961Sphk s = splclock(); /* XXX still needed ? */ 4281541Srgrimes if (uap->which == ITIMER_REAL) { 4291541Srgrimes /* 43036128Sbde * Convert from absolute to relative time in .it_value 4311541Srgrimes * part of real time timer. If time for real time timer 4321541Srgrimes * has passed return 0, else return difference between 4331541Srgrimes * current time and time for the timer to go off. 4341541Srgrimes */ 4351541Srgrimes aitv = p->p_realtimer; 43635058Sphk if (timevalisset(&aitv.it_value)) { 43736119Sphk getmicrouptime(&ctv); 43835058Sphk if (timevalcmp(&aitv.it_value, &ctv, <)) 43935058Sphk timevalclear(&aitv.it_value); 4401541Srgrimes else 44134961Sphk timevalsub(&aitv.it_value, &ctv); 44234961Sphk } 4431541Srgrimes } else 4441541Srgrimes aitv = p->p_stats->p_timer[uap->which]; 4451541Srgrimes splx(s); 4461541Srgrimes return (copyout((caddr_t)&aitv, (caddr_t)uap->itv, 4471541Srgrimes sizeof (struct itimerval))); 4481541Srgrimes} 4491541Srgrimes 45012221Sbde#ifndef _SYS_SYSPROTO_H_ 4511541Srgrimesstruct setitimer_args { 4521541Srgrimes u_int which; 4531541Srgrimes struct itimerval *itv, *oitv; 4541541Srgrimes}; 45512221Sbde#endif 4561541Srgrimes/* ARGSUSED */ 4571549Srgrimesint 45830994Sphksetitimer(p, uap) 4591541Srgrimes struct proc *p; 4601541Srgrimes register struct setitimer_args *uap; 4611541Srgrimes{ 4621541Srgrimes struct itimerval aitv; 46334961Sphk struct timeval ctv; 4641541Srgrimes register struct itimerval *itvp; 4651541Srgrimes int s, error; 4661541Srgrimes 4671541Srgrimes if (uap->which > ITIMER_PROF) 4681541Srgrimes return (EINVAL); 4691541Srgrimes itvp = uap->itv; 4701541Srgrimes if (itvp && (error = copyin((caddr_t)itvp, (caddr_t)&aitv, 4711541Srgrimes sizeof(struct itimerval)))) 4721541Srgrimes return (error); 47312381Sbde if ((uap->itv = uap->oitv) && 47430994Sphk (error = getitimer(p, (struct getitimer_args *)uap))) 4751541Srgrimes return (error); 4761541Srgrimes if (itvp == 0) 4771541Srgrimes return (0); 47828213Sache if (itimerfix(&aitv.it_value)) 4791541Srgrimes return (EINVAL); 48035058Sphk if (!timevalisset(&aitv.it_value)) 48135058Sphk timevalclear(&aitv.it_interval); 48228213Sache else if (itimerfix(&aitv.it_interval)) 48328213Sache return (EINVAL); 48434961Sphk s = splclock(); /* XXX: still needed ? */ 4851541Srgrimes if (uap->which == ITIMER_REAL) { 48635058Sphk if (timevalisset(&p->p_realtimer.it_value)) 48729680Sgibbs untimeout(realitexpire, (caddr_t)p, p->p_ithandle); 48835058Sphk if (timevalisset(&aitv.it_value)) 48929680Sgibbs p->p_ithandle = timeout(realitexpire, (caddr_t)p, 49035033Sphk tvtohz(&aitv.it_value)); 49136119Sphk getmicrouptime(&ctv); 49235044Sphk timevaladd(&aitv.it_value, &ctv); 4931541Srgrimes p->p_realtimer = aitv; 4941541Srgrimes } else 4951541Srgrimes p->p_stats->p_timer[uap->which] = aitv; 4961541Srgrimes splx(s); 4971541Srgrimes return (0); 4981541Srgrimes} 4991541Srgrimes 5001541Srgrimes/* 5011541Srgrimes * Real interval timer expired: 5021541Srgrimes * send process whose timer expired an alarm signal. 5031541Srgrimes * If time is not set up to reload, then just return. 5041541Srgrimes * Else compute next time timer should go off which is > current time. 5051541Srgrimes * This is where delay in processing this timeout causes multiple 5061541Srgrimes * SIGALRM calls to be compressed into one. 50736127Sbde * tvtohz() always adds 1 to allow for the time until the next clock 5089327Sbde * interrupt being strictly less than 1 clock tick, but we don't want 5099327Sbde * that here since we want to appear to be in sync with the clock 5109327Sbde * interrupt even when we're delayed. 5111541Srgrimes */ 5121541Srgrimesvoid 5131541Srgrimesrealitexpire(arg) 5141541Srgrimes void *arg; 5151541Srgrimes{ 5161541Srgrimes register struct proc *p; 51735044Sphk struct timeval ctv, ntv; 5181541Srgrimes int s; 5191541Srgrimes 5201541Srgrimes p = (struct proc *)arg; 5211541Srgrimes psignal(p, SIGALRM); 52235058Sphk if (!timevalisset(&p->p_realtimer.it_interval)) { 52335058Sphk timevalclear(&p->p_realtimer.it_value); 5241541Srgrimes return; 5251541Srgrimes } 5261541Srgrimes for (;;) { 52734961Sphk s = splclock(); /* XXX: still neeeded ? */ 5281541Srgrimes timevaladd(&p->p_realtimer.it_value, 5291541Srgrimes &p->p_realtimer.it_interval); 53036119Sphk getmicrouptime(&ctv); 53135058Sphk if (timevalcmp(&p->p_realtimer.it_value, &ctv, >)) { 53235044Sphk ntv = p->p_realtimer.it_value; 53335044Sphk timevalsub(&ntv, &ctv); 53436128Sbde p->p_ithandle = timeout(realitexpire, (caddr_t)p, 53536128Sbde tvtohz(&ntv) - 1); 5361541Srgrimes splx(s); 5371541Srgrimes return; 5381541Srgrimes } 5391541Srgrimes splx(s); 5401541Srgrimes } 5411541Srgrimes} 5421541Srgrimes 5431541Srgrimes/* 5441541Srgrimes * Check that a proposed value to load into the .it_value or 5451541Srgrimes * .it_interval part of an interval timer is acceptable, and 5461541Srgrimes * fix it to have at least minimal value (i.e. if it is less 5471541Srgrimes * than the resolution of the clock, round it up.) 5481541Srgrimes */ 5491549Srgrimesint 5501541Srgrimesitimerfix(tv) 5511541Srgrimes struct timeval *tv; 5521541Srgrimes{ 5531541Srgrimes 5541541Srgrimes if (tv->tv_sec < 0 || tv->tv_sec > 100000000 || 5551541Srgrimes tv->tv_usec < 0 || tv->tv_usec >= 1000000) 5561541Srgrimes return (EINVAL); 5571541Srgrimes if (tv->tv_sec == 0 && tv->tv_usec != 0 && tv->tv_usec < tick) 5581541Srgrimes tv->tv_usec = tick; 5591541Srgrimes return (0); 5601541Srgrimes} 5611541Srgrimes 5621541Srgrimes/* 5631541Srgrimes * Decrement an interval timer by a specified number 5641541Srgrimes * of microseconds, which must be less than a second, 5651541Srgrimes * i.e. < 1000000. If the timer expires, then reload 5661541Srgrimes * it. In this case, carry over (usec - old value) to 5671541Srgrimes * reduce the value reloaded into the timer so that 5681541Srgrimes * the timer does not drift. This routine assumes 5691541Srgrimes * that it is called in a context where the timers 5701541Srgrimes * on which it is operating cannot change in value. 5711541Srgrimes */ 5721549Srgrimesint 5731541Srgrimesitimerdecr(itp, usec) 5741541Srgrimes register struct itimerval *itp; 5751541Srgrimes int usec; 5761541Srgrimes{ 5771541Srgrimes 5781541Srgrimes if (itp->it_value.tv_usec < usec) { 5791541Srgrimes if (itp->it_value.tv_sec == 0) { 5801541Srgrimes /* expired, and already in next interval */ 5811541Srgrimes usec -= itp->it_value.tv_usec; 5821541Srgrimes goto expire; 5831541Srgrimes } 5841541Srgrimes itp->it_value.tv_usec += 1000000; 5851541Srgrimes itp->it_value.tv_sec--; 5861541Srgrimes } 5871541Srgrimes itp->it_value.tv_usec -= usec; 5881541Srgrimes usec = 0; 58935058Sphk if (timevalisset(&itp->it_value)) 5901541Srgrimes return (1); 5911541Srgrimes /* expired, exactly at end of interval */ 5921541Srgrimesexpire: 59335058Sphk if (timevalisset(&itp->it_interval)) { 5941541Srgrimes itp->it_value = itp->it_interval; 5951541Srgrimes itp->it_value.tv_usec -= usec; 5961541Srgrimes if (itp->it_value.tv_usec < 0) { 5971541Srgrimes itp->it_value.tv_usec += 1000000; 5981541Srgrimes itp->it_value.tv_sec--; 5991541Srgrimes } 6001541Srgrimes } else 6011541Srgrimes itp->it_value.tv_usec = 0; /* sec is already 0 */ 6021541Srgrimes return (0); 6031541Srgrimes} 6041541Srgrimes 6051541Srgrimes/* 6061541Srgrimes * Add and subtract routines for timevals. 6071541Srgrimes * N.B.: subtract routine doesn't deal with 6081541Srgrimes * results which are before the beginning, 6091541Srgrimes * it just gets very confused in this case. 6101541Srgrimes * Caveat emptor. 6111541Srgrimes */ 6121549Srgrimesvoid 6131541Srgrimestimevaladd(t1, t2) 6141541Srgrimes struct timeval *t1, *t2; 6151541Srgrimes{ 6161541Srgrimes 6171541Srgrimes t1->tv_sec += t2->tv_sec; 6181541Srgrimes t1->tv_usec += t2->tv_usec; 6191541Srgrimes timevalfix(t1); 6201541Srgrimes} 6211541Srgrimes 6221549Srgrimesvoid 6231541Srgrimestimevalsub(t1, t2) 6241541Srgrimes struct timeval *t1, *t2; 6251541Srgrimes{ 6261541Srgrimes 6271541Srgrimes t1->tv_sec -= t2->tv_sec; 6281541Srgrimes t1->tv_usec -= t2->tv_usec; 6291541Srgrimes timevalfix(t1); 6301541Srgrimes} 6311541Srgrimes 63212819Sphkstatic void 6331541Srgrimestimevalfix(t1) 6341541Srgrimes struct timeval *t1; 6351541Srgrimes{ 6361541Srgrimes 6371541Srgrimes if (t1->tv_usec < 0) { 6381541Srgrimes t1->tv_sec--; 6391541Srgrimes t1->tv_usec += 1000000; 6401541Srgrimes } 6411541Srgrimes if (t1->tv_usec >= 1000000) { 6421541Srgrimes t1->tv_sec++; 6431541Srgrimes t1->tv_usec -= 1000000; 6441541Srgrimes } 6451541Srgrimes} 646