kern_time.c revision 103964
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 103964 2002-09-25 12:00:38Z bde $ 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 82102074Sphksettime(struct thread *td, struct timeval *tv) 8325583Speter{ 8445433Snsayer struct timeval delta, tv1, tv2; 8545438Snsayer static struct timeval maxtime, laststep; 8633690Sphk struct timespec ts; 8725583Speter int s; 8825583Speter 8925656Speter s = splclock(); 9033818Sbde microtime(&tv1); 9135029Sphk delta = *tv; 9235029Sphk timevalsub(&delta, &tv1); 9325583Speter 9425583Speter /* 9533818Sbde * If the system is secure, we do not allow the time to be 9645433Snsayer * set to a value earlier than 1 second less than the highest 9745433Snsayer * time we have yet seen. The worst a miscreant can do in 9845433Snsayer * this circumstance is "freeze" time. He couldn't go 9945433Snsayer * back to the past. 10045438Snsayer * 10145438Snsayer * We similarly do not allow the clock to be stepped more 10245438Snsayer * than one second, nor more than once per second. This allows 10345438Snsayer * a miscreant to make the clock march double-time, but no worse. 10425583Speter */ 10594343Sjhb if (securelevel_gt(td->td_ucred, 1) != 0) { 10645433Snsayer if (delta.tv_sec < 0 || delta.tv_usec < 0) { 10745437Smjacob /* 10845438Snsayer * Update maxtime to latest time we've seen. 10945437Smjacob */ 11045437Smjacob if (tv1.tv_sec > maxtime.tv_sec) 11145437Smjacob maxtime = tv1; 11245437Smjacob tv2 = *tv; 11345437Smjacob timevalsub(&tv2, &maxtime); 11445437Smjacob if (tv2.tv_sec < -1) { 11545437Smjacob tv->tv_sec = maxtime.tv_sec - 1; 11645433Snsayer printf("Time adjustment clamped to -1 second\n"); 11745433Snsayer } 11845437Smjacob } else { 11945438Snsayer if (tv1.tv_sec == laststep.tv_sec) { 12045438Snsayer splx(s); 12145438Snsayer return (EPERM); 12245438Snsayer } 12345438Snsayer if (delta.tv_sec > 1) { 12445438Snsayer tv->tv_sec = tv1.tv_sec + 1; 12545438Snsayer printf("Time adjustment clamped to +1 second\n"); 12645438Snsayer } 12745438Snsayer laststep = *tv; 12845433Snsayer } 12933818Sbde } 13033818Sbde 13133690Sphk ts.tv_sec = tv->tv_sec; 13233690Sphk ts.tv_nsec = tv->tv_usec * 1000; 13394343Sjhb mtx_lock(&Giant); 13458377Sphk tc_setclock(&ts); 13525583Speter (void) splsoftclock(); 13625583Speter lease_updatetime(delta.tv_sec); 13725583Speter splx(s); 13825583Speter resettodr(); 13994343Sjhb mtx_unlock(&Giant); 14025583Speter return (0); 14125583Speter} 14225583Speter 14312221Sbde#ifndef _SYS_SYSPROTO_H_ 14425583Speterstruct clock_gettime_args { 14525583Speter clockid_t clock_id; 14625583Speter struct timespec *tp; 14725583Speter}; 14825583Speter#endif 14925656Speter 15082746Sdillon/* 15182746Sdillon * MPSAFE 15282746Sdillon */ 15325583Speter/* ARGSUSED */ 15425583Speterint 155102074Sphkclock_gettime(struct thread *td, struct clock_gettime_args *uap) 15625583Speter{ 15725583Speter struct timespec ats; 15825583Speter 15925656Speter if (SCARG(uap, clock_id) != CLOCK_REALTIME) 16025583Speter return (EINVAL); 16182746Sdillon mtx_lock(&Giant); 16233690Sphk nanotime(&ats); 16382746Sdillon mtx_unlock(&Giant); 16425656Speter return (copyout(&ats, SCARG(uap, tp), sizeof(ats))); 16525583Speter} 16625583Speter 16725583Speter#ifndef _SYS_SYSPROTO_H_ 16825583Speterstruct clock_settime_args { 16925583Speter clockid_t clock_id; 17025583Speter const struct timespec *tp; 17125583Speter}; 17225583Speter#endif 17325656Speter 17482746Sdillon/* 17582746Sdillon * MPSAFE 17682746Sdillon */ 17725583Speter/* ARGSUSED */ 17825583Speterint 179102074Sphkclock_settime(struct thread *td, struct clock_settime_args *uap) 18025583Speter{ 18125583Speter struct timeval atv; 18225583Speter struct timespec ats; 18325583Speter int error; 18425583Speter 18593593Sjhb if ((error = suser(td)) != 0) 18694343Sjhb return (error); 18794343Sjhb if (SCARG(uap, clock_id) != CLOCK_REALTIME) 18894343Sjhb return (EINVAL); 18925583Speter if ((error = copyin(SCARG(uap, tp), &ats, sizeof(ats))) != 0) 19094343Sjhb return (error); 19194343Sjhb if (ats.tv_nsec < 0 || ats.tv_nsec >= 1000000000) 19294343Sjhb return (EINVAL); 19334901Sphk /* XXX Don't convert nsec->usec and back */ 19425583Speter TIMESPEC_TO_TIMEVAL(&atv, &ats); 19594343Sjhb error = settime(td, &atv); 19682746Sdillon return (error); 19725583Speter} 19825583Speter 19925583Speter#ifndef _SYS_SYSPROTO_H_ 20025583Speterstruct clock_getres_args { 20125583Speter clockid_t clock_id; 20225583Speter struct timespec *tp; 20325583Speter}; 20425583Speter#endif 20525656Speter 20625583Speterint 207102074Sphkclock_getres(struct thread *td, struct clock_getres_args *uap) 20825583Speter{ 20925583Speter struct timespec ts; 21025656Speter int error; 21125583Speter 21225656Speter if (SCARG(uap, clock_id) != CLOCK_REALTIME) 21325583Speter return (EINVAL); 21425656Speter error = 0; 21525583Speter if (SCARG(uap, tp)) { 21625583Speter ts.tv_sec = 0; 217103964Sbde /* 218103964Sbde * Round up the result of the division cheaply by adding 1. 219103964Sbde * Rounding up is especially important if rounding down 220103964Sbde * would give 0. Perfect rounding is unimportant. 221103964Sbde */ 222103964Sbde ts.tv_nsec = 1000000000 / tc_getfrequency() + 1; 22325656Speter error = copyout(&ts, SCARG(uap, tp), sizeof(ts)); 22425583Speter } 22525656Speter return (error); 22625583Speter} 22725583Speter 22826335Speterstatic int nanowait; 22925656Speter 23026335Speterstatic int 231102074Sphknanosleep1(struct thread *td, struct timespec *rqt, struct timespec *rmt) 23225583Speter{ 23335045Sphk struct timespec ts, ts2, ts3; 23435042Sphk struct timeval tv; 23535042Sphk int error; 23625583Speter 23728773Sbde if (rqt->tv_nsec < 0 || rqt->tv_nsec >= 1000000000) 23825656Speter return (EINVAL); 23943301Sdillon if (rqt->tv_sec < 0 || (rqt->tv_sec == 0 && rqt->tv_nsec == 0)) 24028773Sbde return (0); 24136119Sphk getnanouptime(&ts); 24235029Sphk timespecadd(&ts, rqt); 24335042Sphk TIMESPEC_TO_TIMEVAL(&tv, rqt); 24435042Sphk for (;;) { 24535042Sphk error = tsleep(&nanowait, PWAIT | PCATCH, "nanslp", 24635042Sphk tvtohz(&tv)); 24736119Sphk getnanouptime(&ts2); 24835042Sphk if (error != EWOULDBLOCK) { 24935042Sphk if (error == ERESTART) 25035042Sphk error = EINTR; 25135042Sphk if (rmt != NULL) { 25235042Sphk timespecsub(&ts, &ts2); 25335042Sphk if (ts.tv_sec < 0) 25435042Sphk timespecclear(&ts); 25535042Sphk *rmt = ts; 25635042Sphk } 25735042Sphk return (error); 25835042Sphk } 25935029Sphk if (timespeccmp(&ts2, &ts, >=)) 26035042Sphk return (0); 26135045Sphk ts3 = ts; 26235045Sphk timespecsub(&ts3, &ts2); 26335045Sphk TIMESPEC_TO_TIMEVAL(&tv, &ts3); 26426335Speter } 26526335Speter} 26625583Speter 26726335Speter#ifndef _SYS_SYSPROTO_H_ 26826335Speterstruct nanosleep_args { 26926335Speter struct timespec *rqtp; 27026335Speter struct timespec *rmtp; 27126335Speter}; 27226335Speter#endif 27326335Speter 27482746Sdillon/* 27582746Sdillon * MPSAFE 27682746Sdillon */ 27726335Speter/* ARGSUSED */ 27826335Speterint 279102074Sphknanosleep(struct thread *td, struct nanosleep_args *uap) 28026335Speter{ 28126335Speter struct timespec rmt, rqt; 28282746Sdillon int error; 28326335Speter 28426335Speter error = copyin(SCARG(uap, rqtp), &rqt, sizeof(rqt)); 28526335Speter if (error) 28626335Speter return (error); 28782746Sdillon 28882746Sdillon mtx_lock(&Giant); 28982746Sdillon if (SCARG(uap, rmtp)) { 29052644Sphk if (!useracc((caddr_t)SCARG(uap, rmtp), sizeof(rmt), 29182746Sdillon VM_PROT_WRITE)) { 29282746Sdillon error = EFAULT; 29382746Sdillon goto done2; 29482746Sdillon } 29582746Sdillon } 29683366Sjulian error = nanosleep1(td, &rqt, &rmt); 29735043Speter if (error && SCARG(uap, rmtp)) { 29882746Sdillon int error2; 29982746Sdillon 30025656Speter error2 = copyout(&rmt, SCARG(uap, rmtp), sizeof(rmt)); 30126335Speter if (error2) /* XXX shouldn't happen, did useracc() above */ 30282746Sdillon error = error2; 30325583Speter } 30482746Sdillondone2: 30582746Sdillon mtx_unlock(&Giant); 30625656Speter return (error); 30725583Speter} 30825583Speter 30926335Speter#ifndef _SYS_SYSPROTO_H_ 3101541Srgrimesstruct gettimeofday_args { 3111541Srgrimes struct timeval *tp; 3121541Srgrimes struct timezone *tzp; 3131541Srgrimes}; 31412221Sbde#endif 31582746Sdillon/* 31682746Sdillon * MPSAFE 31782746Sdillon */ 3181541Srgrimes/* ARGSUSED */ 3191549Srgrimesint 320102074Sphkgettimeofday(struct thread *td, struct gettimeofday_args *uap) 3211541Srgrimes{ 3221541Srgrimes struct timeval atv; 3231541Srgrimes int error = 0; 3241541Srgrimes 3251541Srgrimes if (uap->tp) { 3261541Srgrimes microtime(&atv); 32799012Salfred error = copyout(&atv, uap->tp, sizeof (atv)); 3281541Srgrimes } 32990836Sphk if (error == 0 && uap->tzp != NULL) { 33090836Sphk mtx_lock(&Giant); 33199012Salfred error = copyout(&tz, uap->tzp, sizeof (tz)); 33290836Sphk mtx_unlock(&Giant); 33382746Sdillon } 3341541Srgrimes return (error); 3351541Srgrimes} 3361541Srgrimes 33712221Sbde#ifndef _SYS_SYSPROTO_H_ 3381541Srgrimesstruct settimeofday_args { 3391541Srgrimes struct timeval *tv; 3401541Srgrimes struct timezone *tzp; 3411541Srgrimes}; 34212221Sbde#endif 34382746Sdillon/* 34482746Sdillon * MPSAFE 34582746Sdillon */ 3461541Srgrimes/* ARGSUSED */ 3471549Srgrimesint 348102074Sphksettimeofday(struct thread *td, struct settimeofday_args *uap) 3491541Srgrimes{ 35025656Speter struct timeval atv; 3511541Srgrimes struct timezone atz; 35282746Sdillon int error = 0; 3531541Srgrimes 35493593Sjhb if ((error = suser(td))) 35594343Sjhb return (error); 3561541Srgrimes /* Verify all parameters before changing time. */ 35725656Speter if (uap->tv) { 35899012Salfred if ((error = copyin(uap->tv, &atv, sizeof(atv)))) 35994343Sjhb return (error); 36094343Sjhb if (atv.tv_usec < 0 || atv.tv_usec >= 1000000) 36194343Sjhb return (EINVAL); 36225656Speter } 3631541Srgrimes if (uap->tzp && 36499012Salfred (error = copyin(uap->tzp, &atz, sizeof(atz)))) 36594343Sjhb return (error); 36694343Sjhb 36794343Sjhb if (uap->tv && (error = settime(td, &atv))) 36894343Sjhb return (error); 36994343Sjhb if (uap->tzp) { 37094343Sjhb mtx_lock(&Giant); 37194343Sjhb tz = atz; 37294343Sjhb mtx_unlock(&Giant); 37382746Sdillon } 37482746Sdillon return (error); 3751541Srgrimes} 37682746Sdillon/* 3771541Srgrimes * Get value of an interval timer. The process virtual and 3781541Srgrimes * profiling virtual time timers are kept in the p_stats area, since 3791541Srgrimes * they can be swapped out. These are kept internally in the 3801541Srgrimes * way they are specified externally: in time until they expire. 3811541Srgrimes * 3821541Srgrimes * The real time interval timer is kept in the process table slot 3831541Srgrimes * for the process, and its value (it_value) is kept as an 3841541Srgrimes * absolute time rather than as a delta, so that it is easy to keep 3851541Srgrimes * periodic real-time signals from drifting. 3861541Srgrimes * 3871541Srgrimes * Virtual time timers are processed in the hardclock() routine of 3881541Srgrimes * kern_clock.c. The real time timer is processed by a timeout 3891541Srgrimes * routine, called from the softclock() routine. Since a callout 3901541Srgrimes * may be delayed in real time due to interrupt processing in the system, 3911541Srgrimes * it is possible for the real time timeout routine (realitexpire, given below), 3921541Srgrimes * to be delayed in real time past when it is supposed to occur. It 3931541Srgrimes * does not suffice, therefore, to reload the real timer .it_value from the 3941541Srgrimes * real time timers .it_interval. Rather, we compute the next time in 3951541Srgrimes * absolute time the timer should go off. 3961541Srgrimes */ 39712221Sbde#ifndef _SYS_SYSPROTO_H_ 3981541Srgrimesstruct getitimer_args { 3991541Srgrimes u_int which; 4001541Srgrimes struct itimerval *itv; 4011541Srgrimes}; 40212221Sbde#endif 40382746Sdillon/* 40482746Sdillon * MPSAFE 40582746Sdillon */ 4061541Srgrimes/* ARGSUSED */ 4071549Srgrimesint 408102074Sphkgetitimer(struct thread *td, struct getitimer_args *uap) 4091541Srgrimes{ 41083366Sjulian struct proc *p = td->td_proc; 41134961Sphk struct timeval ctv; 4121541Srgrimes struct itimerval aitv; 4131541Srgrimes int s; 41482746Sdillon int error; 4151541Srgrimes 4161541Srgrimes if (uap->which > ITIMER_PROF) 4171541Srgrimes return (EINVAL); 41882746Sdillon 41982746Sdillon mtx_lock(&Giant); 42082746Sdillon 42134961Sphk s = splclock(); /* XXX still needed ? */ 4221541Srgrimes if (uap->which == ITIMER_REAL) { 4231541Srgrimes /* 42436128Sbde * Convert from absolute to relative time in .it_value 4251541Srgrimes * part of real time timer. If time for real time timer 4261541Srgrimes * has passed return 0, else return difference between 4271541Srgrimes * current time and time for the timer to go off. 4281541Srgrimes */ 4291541Srgrimes aitv = p->p_realtimer; 43035058Sphk if (timevalisset(&aitv.it_value)) { 43136119Sphk getmicrouptime(&ctv); 43235058Sphk if (timevalcmp(&aitv.it_value, &ctv, <)) 43335058Sphk timevalclear(&aitv.it_value); 4341541Srgrimes else 43534961Sphk timevalsub(&aitv.it_value, &ctv); 43634961Sphk } 43782746Sdillon } else { 4381541Srgrimes aitv = p->p_stats->p_timer[uap->which]; 43982746Sdillon } 4401541Srgrimes splx(s); 44199012Salfred error = copyout(&aitv, uap->itv, sizeof (struct itimerval)); 44282746Sdillon mtx_unlock(&Giant); 44382746Sdillon return(error); 4441541Srgrimes} 4451541Srgrimes 44612221Sbde#ifndef _SYS_SYSPROTO_H_ 4471541Srgrimesstruct setitimer_args { 4481541Srgrimes u_int which; 4491541Srgrimes struct itimerval *itv, *oitv; 4501541Srgrimes}; 45112221Sbde#endif 45282746Sdillon/* 45382746Sdillon * MPSAFE 45482746Sdillon */ 4551541Srgrimes/* ARGSUSED */ 4561549Srgrimesint 457102074Sphksetitimer(struct thread *td, struct setitimer_args *uap) 4581541Srgrimes{ 45983366Sjulian struct proc *p = td->td_proc; 4601541Srgrimes struct itimerval aitv; 46134961Sphk struct timeval ctv; 462102074Sphk struct itimerval *itvp; 46382746Sdillon int s, error = 0; 4641541Srgrimes 4651541Srgrimes if (uap->which > ITIMER_PROF) 4661541Srgrimes return (EINVAL); 4671541Srgrimes itvp = uap->itv; 46899012Salfred if (itvp && (error = copyin(itvp, &aitv, sizeof(struct itimerval)))) 4691541Srgrimes return (error); 47082746Sdillon 47182746Sdillon mtx_lock(&Giant); 47282746Sdillon 47312381Sbde if ((uap->itv = uap->oitv) && 47483366Sjulian (error = getitimer(td, (struct getitimer_args *)uap))) { 47582746Sdillon goto done2; 47682746Sdillon } 47782746Sdillon if (itvp == 0) { 47882746Sdillon error = 0; 47982746Sdillon goto done2; 48082746Sdillon } 48182746Sdillon if (itimerfix(&aitv.it_value)) { 48282746Sdillon error = EINVAL; 48382746Sdillon goto done2; 48482746Sdillon } 48582746Sdillon if (!timevalisset(&aitv.it_value)) { 48635058Sphk timevalclear(&aitv.it_interval); 48782746Sdillon } else if (itimerfix(&aitv.it_interval)) { 48882746Sdillon error = EINVAL; 48982746Sdillon goto done2; 49082746Sdillon } 49134961Sphk s = splclock(); /* XXX: still needed ? */ 4921541Srgrimes if (uap->which == ITIMER_REAL) { 49335058Sphk if (timevalisset(&p->p_realtimer.it_value)) 49469286Sjake callout_stop(&p->p_itcallout); 49535058Sphk if (timevalisset(&aitv.it_value)) 49669286Sjake callout_reset(&p->p_itcallout, tvtohz(&aitv.it_value), 49769286Sjake realitexpire, p); 49836119Sphk getmicrouptime(&ctv); 49935044Sphk timevaladd(&aitv.it_value, &ctv); 5001541Srgrimes p->p_realtimer = aitv; 50182746Sdillon } else { 5021541Srgrimes p->p_stats->p_timer[uap->which] = aitv; 50382746Sdillon } 5041541Srgrimes splx(s); 50582746Sdillondone2: 50682746Sdillon mtx_unlock(&Giant); 50782746Sdillon return (error); 5081541Srgrimes} 5091541Srgrimes 5101541Srgrimes/* 5111541Srgrimes * Real interval timer expired: 5121541Srgrimes * send process whose timer expired an alarm signal. 5131541Srgrimes * If time is not set up to reload, then just return. 5141541Srgrimes * Else compute next time timer should go off which is > current time. 5151541Srgrimes * This is where delay in processing this timeout causes multiple 5161541Srgrimes * SIGALRM calls to be compressed into one. 51736127Sbde * tvtohz() always adds 1 to allow for the time until the next clock 5189327Sbde * interrupt being strictly less than 1 clock tick, but we don't want 5199327Sbde * that here since we want to appear to be in sync with the clock 5209327Sbde * interrupt even when we're delayed. 5211541Srgrimes */ 5221541Srgrimesvoid 523102074Sphkrealitexpire(void *arg) 5241541Srgrimes{ 525102074Sphk struct proc *p; 52635044Sphk struct timeval ctv, ntv; 5271541Srgrimes int s; 5281541Srgrimes 5291541Srgrimes p = (struct proc *)arg; 53073916Sjhb PROC_LOCK(p); 5311541Srgrimes psignal(p, SIGALRM); 53235058Sphk if (!timevalisset(&p->p_realtimer.it_interval)) { 53335058Sphk timevalclear(&p->p_realtimer.it_value); 53473916Sjhb PROC_UNLOCK(p); 5351541Srgrimes return; 5361541Srgrimes } 5371541Srgrimes for (;;) { 53834961Sphk s = splclock(); /* XXX: still neeeded ? */ 5391541Srgrimes timevaladd(&p->p_realtimer.it_value, 5401541Srgrimes &p->p_realtimer.it_interval); 54136119Sphk getmicrouptime(&ctv); 54235058Sphk if (timevalcmp(&p->p_realtimer.it_value, &ctv, >)) { 54335044Sphk ntv = p->p_realtimer.it_value; 54435044Sphk timevalsub(&ntv, &ctv); 54569286Sjake callout_reset(&p->p_itcallout, tvtohz(&ntv) - 1, 54669286Sjake realitexpire, p); 5471541Srgrimes splx(s); 54873916Sjhb PROC_UNLOCK(p); 5491541Srgrimes return; 5501541Srgrimes } 5511541Srgrimes splx(s); 5521541Srgrimes } 55373916Sjhb /*NOTREACHED*/ 5541541Srgrimes} 5551541Srgrimes 5561541Srgrimes/* 5571541Srgrimes * Check that a proposed value to load into the .it_value or 5581541Srgrimes * .it_interval part of an interval timer is acceptable, and 5591541Srgrimes * fix it to have at least minimal value (i.e. if it is less 5601541Srgrimes * than the resolution of the clock, round it up.) 5611541Srgrimes */ 5621549Srgrimesint 563102074Sphkitimerfix(struct timeval *tv) 5641541Srgrimes{ 5651541Srgrimes 5661541Srgrimes if (tv->tv_sec < 0 || tv->tv_sec > 100000000 || 5671541Srgrimes tv->tv_usec < 0 || tv->tv_usec >= 1000000) 5681541Srgrimes return (EINVAL); 5691541Srgrimes if (tv->tv_sec == 0 && tv->tv_usec != 0 && tv->tv_usec < tick) 5701541Srgrimes tv->tv_usec = tick; 5711541Srgrimes return (0); 5721541Srgrimes} 5731541Srgrimes 5741541Srgrimes/* 5751541Srgrimes * Decrement an interval timer by a specified number 5761541Srgrimes * of microseconds, which must be less than a second, 5771541Srgrimes * i.e. < 1000000. If the timer expires, then reload 5781541Srgrimes * it. In this case, carry over (usec - old value) to 5791541Srgrimes * reduce the value reloaded into the timer so that 5801541Srgrimes * the timer does not drift. This routine assumes 5811541Srgrimes * that it is called in a context where the timers 5821541Srgrimes * on which it is operating cannot change in value. 5831541Srgrimes */ 5841549Srgrimesint 585102074Sphkitimerdecr(struct itimerval *itp, int usec) 5861541Srgrimes{ 5871541Srgrimes 5881541Srgrimes if (itp->it_value.tv_usec < usec) { 5891541Srgrimes if (itp->it_value.tv_sec == 0) { 5901541Srgrimes /* expired, and already in next interval */ 5911541Srgrimes usec -= itp->it_value.tv_usec; 5921541Srgrimes goto expire; 5931541Srgrimes } 5941541Srgrimes itp->it_value.tv_usec += 1000000; 5951541Srgrimes itp->it_value.tv_sec--; 5961541Srgrimes } 5971541Srgrimes itp->it_value.tv_usec -= usec; 5981541Srgrimes usec = 0; 59935058Sphk if (timevalisset(&itp->it_value)) 6001541Srgrimes return (1); 6011541Srgrimes /* expired, exactly at end of interval */ 6021541Srgrimesexpire: 60335058Sphk if (timevalisset(&itp->it_interval)) { 6041541Srgrimes itp->it_value = itp->it_interval; 6051541Srgrimes itp->it_value.tv_usec -= usec; 6061541Srgrimes if (itp->it_value.tv_usec < 0) { 6071541Srgrimes itp->it_value.tv_usec += 1000000; 6081541Srgrimes itp->it_value.tv_sec--; 6091541Srgrimes } 6101541Srgrimes } else 6111541Srgrimes itp->it_value.tv_usec = 0; /* sec is already 0 */ 6121541Srgrimes return (0); 6131541Srgrimes} 6141541Srgrimes 6151541Srgrimes/* 6161541Srgrimes * Add and subtract routines for timevals. 6171541Srgrimes * N.B.: subtract routine doesn't deal with 6181541Srgrimes * results which are before the beginning, 6191541Srgrimes * it just gets very confused in this case. 6201541Srgrimes * Caveat emptor. 6211541Srgrimes */ 6221549Srgrimesvoid 623102074Sphktimevaladd(struct timeval *t1, struct timeval *t2) 6241541Srgrimes{ 6251541Srgrimes 6261541Srgrimes t1->tv_sec += t2->tv_sec; 6271541Srgrimes t1->tv_usec += t2->tv_usec; 6281541Srgrimes timevalfix(t1); 6291541Srgrimes} 6301541Srgrimes 6311549Srgrimesvoid 632102074Sphktimevalsub(struct timeval *t1, struct timeval *t2) 6331541Srgrimes{ 6341541Srgrimes 6351541Srgrimes t1->tv_sec -= t2->tv_sec; 6361541Srgrimes t1->tv_usec -= t2->tv_usec; 6371541Srgrimes timevalfix(t1); 6381541Srgrimes} 6391541Srgrimes 64012819Sphkstatic void 641102074Sphktimevalfix(struct timeval *t1) 6421541Srgrimes{ 6431541Srgrimes 6441541Srgrimes if (t1->tv_usec < 0) { 6451541Srgrimes t1->tv_sec--; 6461541Srgrimes t1->tv_usec += 1000000; 6471541Srgrimes } 6481541Srgrimes if (t1->tv_usec >= 1000000) { 6491541Srgrimes t1->tv_sec++; 6501541Srgrimes t1->tv_usec -= 1000000; 6511541Srgrimes } 6521541Srgrimes} 653