kern_time.c revision 25583
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 3425583Speter * $Id: kern_time.c,v 1.22 1997/03/22 08:03:32 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> 451541Srgrimes#include <sys/vnode.h> 461541Srgrimes 479369Sdgstruct timezone tz; 489369Sdg 498876Srgrimes/* 501541Srgrimes * Time of day and interval timer support. 511541Srgrimes * 521541Srgrimes * These routines provide the kernel entry points to get and set 531541Srgrimes * the time-of-day and per-process interval timers. Subroutines 541541Srgrimes * here provide support for adding and subtracting timeval structures 551541Srgrimes * and decrementing interval timers, optionally reloading the interval 561541Srgrimes * timers when they expire. 571541Srgrimes */ 581541Srgrimes 5913016Sbdestatic void timevalfix __P((struct timeval *)); 6025583Speterstatic int settime __P((struct timeval *)); 6113016Sbde 6225583Speterstatic int 6325583Spetersettime(tv) 6425583Speter struct timeval *tv; 6525583Speter{ 6625583Speter struct timeval delta; 6725583Speter struct proc *p; 6825583Speter int s; 6925583Speter 7025583Speter /* 7125583Speter * Must not set clock backwards in secure mode 7225583Speter */ 7325583Speter delta.tv_sec = tv->tv_sec - time.tv_sec; 7425583Speter delta.tv_usec = tv->tv_usec - time.tv_usec; 7525583Speter timevalfix(&delta); 7625583Speter if (delta.tv_sec < 0 && securelevel > 1) 7725583Speter return (EPERM); 7825583Speter#ifdef notyet 7925583Speter if (delta.tv_sec < 86400 && securelevel > 0) 8025583Speter return (EPERM); 8125583Speter#endif 8225583Speter 8325583Speter s = splclock(); 8425583Speter /* 8525583Speter * Recalculate delta directly to minimize clock interrupt 8625583Speter * latency. Fix it after the ipl has been lowered. 8725583Speter */ 8825583Speter delta.tv_sec = tv->tv_sec - time.tv_sec; 8925583Speter delta.tv_usec = tv->tv_usec - time.tv_usec; 9025583Speter time = *tv; 9125583Speter /* 9225583Speter * XXX should arrange for microtime() to agree with *tv if 9325583Speter * it is called now. As it is, it may add up to about 9425583Speter * `tick' unwanted usec. 9525583Speter * Another problem is that clock interrupts may occur at 9625583Speter * other than multiples of `tick'. It's not worth fixing 9725583Speter * this here, since the problem is also caused by tick 9825583Speter * adjustments. 9925583Speter */ 10025583Speter (void) splsoftclock(); 10125583Speter timevaladd(&boottime, &delta); 10225583Speter timevaladd(&runtime, &delta); 10325583Speter for (p = allproc.lh_first; p != 0; p = p->p_list.le_next) 10425583Speter if (timerisset(&p->p_realtimer.it_value)) 10525583Speter timevaladd(&p->p_realtimer.it_value, &delta); 10625583Speter#ifdef NFS 10725583Speter lease_updatetime(delta.tv_sec); 10825583Speter#endif 10925583Speter splx(s); 11025583Speter resettodr(); 11125583Speter return (0); 11225583Speter} 11325583Speter 11412221Sbde#ifndef _SYS_SYSPROTO_H_ 11525583Speterstruct clock_gettime_args { 11625583Speter clockid_t clock_id; 11725583Speter struct timespec *tp; 11825583Speter}; 11925583Speter#endif 12025583Speter/* ARGSUSED */ 12125583Speterint 12225583Speterclock_gettime(p, uap, retval) 12325583Speter struct proc *p; 12425583Speter struct clock_gettime_args *uap; 12525583Speter register_t *retval; 12625583Speter{ 12725583Speter clockid_t clock_id; 12825583Speter struct timeval atv; 12925583Speter struct timespec ats; 13025583Speter 13125583Speter clock_id = SCARG(uap, clock_id); 13225583Speter if (clock_id != CLOCK_REALTIME) 13325583Speter return (EINVAL); 13425583Speter 13525583Speter microtime(&atv); 13625583Speter TIMEVAL_TO_TIMESPEC(&atv, &ats); 13725583Speter 13825583Speter return copyout(&ats, SCARG(uap, tp), sizeof(ats)); 13925583Speter} 14025583Speter 14125583Speter#ifndef _SYS_SYSPROTO_H_ 14225583Speterstruct clock_settime_args { 14325583Speter clockid_t clock_id; 14425583Speter const struct timespec *tp; 14525583Speter}; 14625583Speter#endif 14725583Speter/* ARGSUSED */ 14825583Speterint 14925583Speterclock_settime(p, uap, retval) 15025583Speter struct proc *p; 15125583Speter struct clock_settime_args *uap; 15225583Speter register_t *retval; 15325583Speter{ 15425583Speter clockid_t clock_id; 15525583Speter struct timeval atv; 15625583Speter struct timespec ats; 15725583Speter int error; 15825583Speter 15925583Speter if ((error = suser(p->p_ucred, &p->p_acflag)) != 0) 16025583Speter return (error); 16125583Speter 16225583Speter clock_id = SCARG(uap, clock_id); 16325583Speter if (clock_id != CLOCK_REALTIME) 16425583Speter return (EINVAL); 16525583Speter 16625583Speter if ((error = copyin(SCARG(uap, tp), &ats, sizeof(ats))) != 0) 16725583Speter return (error); 16825583Speter 16925583Speter TIMESPEC_TO_TIMEVAL(&atv, &ats); 17025583Speter if ((error = settime(&atv))) 17125583Speter return (error); 17225583Speter 17325583Speter return 0; 17425583Speter} 17525583Speter 17625583Speter#ifndef _SYS_SYSPROTO_H_ 17725583Speterstruct clock_getres_args { 17825583Speter clockid_t clock_id; 17925583Speter struct timespec *tp; 18025583Speter}; 18125583Speter#endif 18225583Speterint 18325583Speterclock_getres(p, uap, retval) 18425583Speter struct proc *p; 18525583Speter struct clock_getres_args *uap; 18625583Speter register_t *retval; 18725583Speter{ 18825583Speter clockid_t clock_id; 18925583Speter struct timespec ts; 19025583Speter int error = 0; 19125583Speter 19225583Speter clock_id = SCARG(uap, clock_id); 19325583Speter if (clock_id != CLOCK_REALTIME) 19425583Speter return (EINVAL); 19525583Speter 19625583Speter if (SCARG(uap, tp)) { 19725583Speter ts.tv_sec = 0; 19825583Speter ts.tv_nsec = 1000000000 / hz; 19925583Speter 20025583Speter error = copyout(&ts, SCARG(uap, tp), sizeof (ts)); 20125583Speter } 20225583Speter 20325583Speter return error; 20425583Speter} 20525583Speter 20625583Speter#ifndef _SYS_SYSPROTO_H_ 20725583Speterstruct nanosleep_args { 20825583Speter struct timespec *rqtp; 20925583Speter struct timespec *rmtp; 21025583Speter}; 21125583Speter#endif 21225583Speter/* ARGSUSED */ 21325583Speterint 21425583Speternanosleep(p, uap, retval) 21525583Speter struct proc *p; 21625583Speter struct nanosleep_args *uap; 21725583Speter register_t *retval; 21825583Speter{ 21925583Speter static int nanowait; 22025583Speter struct timespec rqt; 22125583Speter struct timespec rmt; 22225583Speter struct timeval atv, utv; 22325583Speter int error, s, timo; 22425583Speter 22525583Speter error = copyin((caddr_t)SCARG(uap, rqtp), (caddr_t)&rqt, 22625583Speter sizeof(struct timespec)); 22725583Speter if (error) 22825583Speter return (error); 22925583Speter 23025583Speter TIMESPEC_TO_TIMEVAL(&atv, &rqt) 23125583Speter if (itimerfix(&atv)) 23225583Speter return (EINVAL); 23325583Speter 23425583Speter s = splclock(); 23525583Speter timevaladd(&atv, &time); 23625583Speter timo = hzto(&atv); 23725583Speter /* 23825583Speter * Avoid inadvertantly sleeping forever 23925583Speter */ 24025583Speter if (timo == 0) 24125583Speter timo = 1; 24225583Speter splx(s); 24325583Speter 24425583Speter error = tsleep(&nanowait, PWAIT | PCATCH, "nanosleep", timo); 24525583Speter if (error == ERESTART) 24625583Speter error = EINTR; 24725583Speter if (error == EWOULDBLOCK) 24825583Speter error = 0; 24925583Speter 25025583Speter if (SCARG(uap, rmtp)) { 25125583Speter int error; 25225583Speter 25325583Speter s = splclock(); 25425583Speter utv = time; 25525583Speter splx(s); 25625583Speter 25725583Speter timevalsub(&atv, &utv); 25825583Speter if (atv.tv_sec < 0) 25925583Speter timerclear(&atv); 26025583Speter 26125583Speter TIMEVAL_TO_TIMESPEC(&atv, &rmt); 26225583Speter error = copyout((caddr_t)&rmt, (caddr_t)SCARG(uap, rmtp), 26325583Speter sizeof(rmt)); 26425583Speter if (error) 26525583Speter return (error); 26625583Speter } 26725583Speter 26825583Speter return error; 26925583Speter} 27025583Speter 27125583Speter 27225583Speter#ifndef _SYS_SYSPROTO_H_ 2731541Srgrimesstruct gettimeofday_args { 2741541Srgrimes struct timeval *tp; 2751541Srgrimes struct timezone *tzp; 2761541Srgrimes}; 27712221Sbde#endif 2781541Srgrimes/* ARGSUSED */ 2791549Srgrimesint 2801541Srgrimesgettimeofday(p, uap, retval) 2811541Srgrimes struct proc *p; 2821541Srgrimes register struct gettimeofday_args *uap; 2831541Srgrimes int *retval; 2841541Srgrimes{ 2851541Srgrimes struct timeval atv; 2861541Srgrimes int error = 0; 2871541Srgrimes 2881541Srgrimes if (uap->tp) { 2891541Srgrimes microtime(&atv); 2903098Sphk if ((error = copyout((caddr_t)&atv, (caddr_t)uap->tp, 2913098Sphk sizeof (atv)))) 2921541Srgrimes return (error); 2931541Srgrimes } 2941541Srgrimes if (uap->tzp) 2951541Srgrimes error = copyout((caddr_t)&tz, (caddr_t)uap->tzp, 2961541Srgrimes sizeof (tz)); 2971541Srgrimes return (error); 2981541Srgrimes} 2991541Srgrimes 30012221Sbde#ifndef _SYS_SYSPROTO_H_ 3011541Srgrimesstruct settimeofday_args { 3021541Srgrimes struct timeval *tv; 3031541Srgrimes struct timezone *tzp; 3041541Srgrimes}; 30512221Sbde#endif 3061541Srgrimes/* ARGSUSED */ 3071549Srgrimesint 3081541Srgrimessettimeofday(p, uap, retval) 3091541Srgrimes struct proc *p; 3101541Srgrimes struct settimeofday_args *uap; 3111541Srgrimes int *retval; 3121541Srgrimes{ 3131541Srgrimes struct timeval atv, delta; 3141541Srgrimes struct timezone atz; 3151541Srgrimes int error, s; 3161541Srgrimes 3173098Sphk if ((error = suser(p->p_ucred, &p->p_acflag))) 3181541Srgrimes return (error); 3191541Srgrimes /* Verify all parameters before changing time. */ 3201541Srgrimes if (uap->tv && 3211541Srgrimes (error = copyin((caddr_t)uap->tv, (caddr_t)&atv, sizeof(atv)))) 3221541Srgrimes return (error); 32312381Sbde if (atv.tv_usec < 0 || atv.tv_usec >= 1000000) 32412381Sbde return (EINVAL); 3251541Srgrimes if (uap->tzp && 3261541Srgrimes (error = copyin((caddr_t)uap->tzp, (caddr_t)&atz, sizeof(atz)))) 3271541Srgrimes return (error); 32825583Speter if (uap->tv && (error = settime(&atv))) 32925583Speter return (error); 3301541Srgrimes if (uap->tzp) 3311541Srgrimes tz = atz; 3321541Srgrimes return (0); 3331541Srgrimes} 3341541Srgrimes 3351541Srgrimesextern int tickadj; /* "standard" clock skew, us./tick */ 3361541Srgrimesint tickdelta; /* current clock skew, us. per tick */ 3371541Srgrimeslong timedelta; /* unapplied time correction, us. */ 33812819Sphkstatic long bigadj = 1000000; /* use 10x skew above bigadj us. */ 3391541Srgrimes 34012221Sbde#ifndef _SYS_SYSPROTO_H_ 3411541Srgrimesstruct adjtime_args { 3421541Srgrimes struct timeval *delta; 3431541Srgrimes struct timeval *olddelta; 3441541Srgrimes}; 34512221Sbde#endif 3461541Srgrimes/* ARGSUSED */ 3471549Srgrimesint 3481541Srgrimesadjtime(p, uap, retval) 3491541Srgrimes struct proc *p; 3501541Srgrimes register struct adjtime_args *uap; 3511541Srgrimes int *retval; 3521541Srgrimes{ 3531541Srgrimes struct timeval atv; 3541541Srgrimes register long ndelta, ntickdelta, odelta; 3551541Srgrimes int s, error; 3561541Srgrimes 3573098Sphk if ((error = suser(p->p_ucred, &p->p_acflag))) 3581541Srgrimes return (error); 3593098Sphk if ((error = 3603098Sphk copyin((caddr_t)uap->delta, (caddr_t)&atv, sizeof(struct timeval)))) 3611541Srgrimes return (error); 3621541Srgrimes 3631541Srgrimes /* 3641541Srgrimes * Compute the total correction and the rate at which to apply it. 3651541Srgrimes * Round the adjustment down to a whole multiple of the per-tick 3661541Srgrimes * delta, so that after some number of incremental changes in 3671541Srgrimes * hardclock(), tickdelta will become zero, lest the correction 3681541Srgrimes * overshoot and start taking us away from the desired final time. 3691541Srgrimes */ 3701541Srgrimes ndelta = atv.tv_sec * 1000000 + atv.tv_usec; 37117123Sbde if (ndelta > bigadj || ndelta < -bigadj) 3721541Srgrimes ntickdelta = 10 * tickadj; 3731541Srgrimes else 3741541Srgrimes ntickdelta = tickadj; 3751541Srgrimes if (ndelta % ntickdelta) 3761541Srgrimes ndelta = ndelta / ntickdelta * ntickdelta; 3771541Srgrimes 3781541Srgrimes /* 3791541Srgrimes * To make hardclock()'s job easier, make the per-tick delta negative 3801541Srgrimes * if we want time to run slower; then hardclock can simply compute 3811541Srgrimes * tick + tickdelta, and subtract tickdelta from timedelta. 3821541Srgrimes */ 3831541Srgrimes if (ndelta < 0) 3841541Srgrimes ntickdelta = -ntickdelta; 3851541Srgrimes s = splclock(); 3861541Srgrimes odelta = timedelta; 3871541Srgrimes timedelta = ndelta; 3881541Srgrimes tickdelta = ntickdelta; 3891541Srgrimes splx(s); 3901541Srgrimes 3911541Srgrimes if (uap->olddelta) { 3921541Srgrimes atv.tv_sec = odelta / 1000000; 3931541Srgrimes atv.tv_usec = odelta % 1000000; 3941541Srgrimes (void) copyout((caddr_t)&atv, (caddr_t)uap->olddelta, 3951541Srgrimes sizeof(struct timeval)); 3961541Srgrimes } 3971541Srgrimes return (0); 3981541Srgrimes} 3991541Srgrimes 4001541Srgrimes/* 4011541Srgrimes * Get value of an interval timer. The process virtual and 4021541Srgrimes * profiling virtual time timers are kept in the p_stats area, since 4031541Srgrimes * they can be swapped out. These are kept internally in the 4041541Srgrimes * way they are specified externally: in time until they expire. 4051541Srgrimes * 4061541Srgrimes * The real time interval timer is kept in the process table slot 4071541Srgrimes * for the process, and its value (it_value) is kept as an 4081541Srgrimes * absolute time rather than as a delta, so that it is easy to keep 4091541Srgrimes * periodic real-time signals from drifting. 4101541Srgrimes * 4111541Srgrimes * Virtual time timers are processed in the hardclock() routine of 4121541Srgrimes * kern_clock.c. The real time timer is processed by a timeout 4131541Srgrimes * routine, called from the softclock() routine. Since a callout 4141541Srgrimes * may be delayed in real time due to interrupt processing in the system, 4151541Srgrimes * it is possible for the real time timeout routine (realitexpire, given below), 4161541Srgrimes * to be delayed in real time past when it is supposed to occur. It 4171541Srgrimes * does not suffice, therefore, to reload the real timer .it_value from the 4181541Srgrimes * real time timers .it_interval. Rather, we compute the next time in 4191541Srgrimes * absolute time the timer should go off. 4201541Srgrimes */ 42112221Sbde#ifndef _SYS_SYSPROTO_H_ 4221541Srgrimesstruct getitimer_args { 4231541Srgrimes u_int which; 4241541Srgrimes struct itimerval *itv; 4251541Srgrimes}; 42612221Sbde#endif 4271541Srgrimes/* ARGSUSED */ 4281549Srgrimesint 4291541Srgrimesgetitimer(p, uap, retval) 4301541Srgrimes struct proc *p; 4311541Srgrimes register struct getitimer_args *uap; 4321541Srgrimes int *retval; 4331541Srgrimes{ 4341541Srgrimes struct itimerval aitv; 4351541Srgrimes int s; 4361541Srgrimes 4371541Srgrimes if (uap->which > ITIMER_PROF) 4381541Srgrimes return (EINVAL); 4391541Srgrimes s = splclock(); 4401541Srgrimes if (uap->which == ITIMER_REAL) { 4411541Srgrimes /* 4421541Srgrimes * Convert from absoulte to relative time in .it_value 4431541Srgrimes * part of real time timer. If time for real time timer 4441541Srgrimes * has passed return 0, else return difference between 4451541Srgrimes * current time and time for the timer to go off. 4461541Srgrimes */ 4471541Srgrimes aitv = p->p_realtimer; 4481541Srgrimes if (timerisset(&aitv.it_value)) 4491541Srgrimes if (timercmp(&aitv.it_value, &time, <)) 4501541Srgrimes timerclear(&aitv.it_value); 4511541Srgrimes else 45224102Sbde timevalsub(&aitv.it_value, &time); 4531541Srgrimes } else 4541541Srgrimes aitv = p->p_stats->p_timer[uap->which]; 4551541Srgrimes splx(s); 4561541Srgrimes return (copyout((caddr_t)&aitv, (caddr_t)uap->itv, 4571541Srgrimes sizeof (struct itimerval))); 4581541Srgrimes} 4591541Srgrimes 46012221Sbde#ifndef _SYS_SYSPROTO_H_ 4611541Srgrimesstruct setitimer_args { 4621541Srgrimes u_int which; 4631541Srgrimes struct itimerval *itv, *oitv; 4641541Srgrimes}; 46512221Sbde#endif 4661541Srgrimes/* ARGSUSED */ 4671549Srgrimesint 4681541Srgrimessetitimer(p, uap, retval) 4691541Srgrimes struct proc *p; 4701541Srgrimes register struct setitimer_args *uap; 4711541Srgrimes int *retval; 4721541Srgrimes{ 4731541Srgrimes struct itimerval aitv; 4741541Srgrimes register struct itimerval *itvp; 4751541Srgrimes int s, error; 4761541Srgrimes 4771541Srgrimes if (uap->which > ITIMER_PROF) 4781541Srgrimes return (EINVAL); 4791541Srgrimes itvp = uap->itv; 4801541Srgrimes if (itvp && (error = copyin((caddr_t)itvp, (caddr_t)&aitv, 4811541Srgrimes sizeof(struct itimerval)))) 4821541Srgrimes return (error); 48312381Sbde if ((uap->itv = uap->oitv) && 48412381Sbde (error = getitimer(p, (struct getitimer_args *)uap, retval))) 4851541Srgrimes return (error); 4861541Srgrimes if (itvp == 0) 4871541Srgrimes return (0); 4881541Srgrimes if (itimerfix(&aitv.it_value) || itimerfix(&aitv.it_interval)) 4891541Srgrimes return (EINVAL); 4901541Srgrimes s = splclock(); 4911541Srgrimes if (uap->which == ITIMER_REAL) { 4921541Srgrimes untimeout(realitexpire, (caddr_t)p); 4931541Srgrimes if (timerisset(&aitv.it_value)) { 49424102Sbde timevaladd(&aitv.it_value, &time); 4951541Srgrimes timeout(realitexpire, (caddr_t)p, hzto(&aitv.it_value)); 4961541Srgrimes } 4971541Srgrimes p->p_realtimer = aitv; 4981541Srgrimes } else 4991541Srgrimes p->p_stats->p_timer[uap->which] = aitv; 5001541Srgrimes splx(s); 5011541Srgrimes return (0); 5021541Srgrimes} 5031541Srgrimes 5041541Srgrimes/* 5051541Srgrimes * Real interval timer expired: 5061541Srgrimes * send process whose timer expired an alarm signal. 5071541Srgrimes * If time is not set up to reload, then just return. 5081541Srgrimes * Else compute next time timer should go off which is > current time. 5091541Srgrimes * This is where delay in processing this timeout causes multiple 5101541Srgrimes * SIGALRM calls to be compressed into one. 5119327Sbde * hzto() always adds 1 to allow for the time until the next clock 5129327Sbde * interrupt being strictly less than 1 clock tick, but we don't want 5139327Sbde * that here since we want to appear to be in sync with the clock 5149327Sbde * interrupt even when we're delayed. 5151541Srgrimes */ 5161541Srgrimesvoid 5171541Srgrimesrealitexpire(arg) 5181541Srgrimes void *arg; 5191541Srgrimes{ 5201541Srgrimes register struct proc *p; 5211541Srgrimes int s; 5221541Srgrimes 5231541Srgrimes p = (struct proc *)arg; 5241541Srgrimes psignal(p, SIGALRM); 5251541Srgrimes if (!timerisset(&p->p_realtimer.it_interval)) { 5261541Srgrimes timerclear(&p->p_realtimer.it_value); 5271541Srgrimes return; 5281541Srgrimes } 5291541Srgrimes for (;;) { 5301541Srgrimes s = splclock(); 5311541Srgrimes timevaladd(&p->p_realtimer.it_value, 5321541Srgrimes &p->p_realtimer.it_interval); 5331541Srgrimes if (timercmp(&p->p_realtimer.it_value, &time, >)) { 5341541Srgrimes timeout(realitexpire, (caddr_t)p, 5359327Sbde hzto(&p->p_realtimer.it_value) - 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; 5891541Srgrimes if (timerisset(&itp->it_value)) 5901541Srgrimes return (1); 5911541Srgrimes /* expired, exactly at end of interval */ 5921541Srgrimesexpire: 5931541Srgrimes if (timerisset(&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