/* * Copyright (c) 2000 Apple Computer, Inc. All rights reserved. * * @APPLE_LICENSE_HEADER_START@ * * The contents of this file constitute Original Code as defined in and * are subject to the Apple Public Source License Version 1.1 (the * "License"). You may not use this file except in compliance with the * License. Please obtain a copy of the License at * http://www.apple.com/publicsource and read it before using this file. * * This Original Code and all software distributed under the License are * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT. Please see the * License for the specific language governing rights and limitations * under the License. * * @APPLE_LICENSE_HEADER_END@ */ /* Copyright (c) 1995 NeXT Computer, Inc. All Rights Reserved */ /* * Copyright (c) 1982, 1986, 1989, 1993 * The Regents of the University of California. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by the University of * California, Berkeley and its contributors. * 4. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * @(#)kern_time.c 8.4 (Berkeley) 5/26/95 */ #include <sys/param.h> #include <sys/resourcevar.h> #include <sys/kernel.h> #include <sys/systm.h> #include <sys/proc.h> #include <sys/vnode.h> #include <sys/mount.h> #include <kern/cpu_number.h> #include <kern/clock.h> #define HZ 100 /* XXX */ struct timeval time; /* * Time of day and interval timer support. * * These routines provide the kernel entry points to get and set * the time-of-day and per-process interval timers. Subroutines * here provide support for adding and subtracting timeval structures * and decrementing interval timers, optionally reloading the interval * timers when they expire. */ struct gettimeofday_args{ struct timeval *tp; struct timezone *tzp; }; /* ARGSUSED */ int gettimeofday(p, uap, retval) struct proc *p; register struct gettimeofday_args *uap; register_t *retval; { struct timeval atv; int error = 0; if (uap->tp) { microtime(&atv); if (error = copyout((caddr_t)&atv, (caddr_t)uap->tp, sizeof (atv))) return(error); } if (uap->tzp) error = copyout((caddr_t)&tz, (caddr_t)uap->tzp, sizeof (tz)); return(error); } struct settimeofday_args { struct timeval *tv; struct timezone *tzp; }; /* ARGSUSED */ int settimeofday(p, uap, retval) struct proc *p; struct settimeofday_args *uap; register_t *retval; { struct timeval atv; struct timezone atz; int error, s; if (error = suser(p->p_ucred, &p->p_acflag)) return (error); /* Verify all parameters before changing time. */ if (uap->tv && (error = copyin((caddr_t)uap->tv, (caddr_t)&atv, sizeof(atv)))) return (error); if (uap->tzp && (error = copyin((caddr_t)uap->tzp, (caddr_t)&atz, sizeof(atz)))) return (error); if (uap->tv) setthetime(&atv); if (uap->tzp) tz = atz; return (0); } setthetime(tv) struct timeval *tv; { mach_timespec_t now; long delta; int s; now.tv_sec = tv->tv_sec; now.tv_nsec = tv->tv_usec * NSEC_PER_USEC; clock_set_calendar_value(now); delta = tv->tv_sec - time.tv_sec; boottime.tv_sec += delta; #if NFSCLIENT || NFSSERVER lease_updatetime(delta); #endif s = splhigh(); microtime(&time); splx(s); } int tickadj = 240000 / (60 * HZ); /* "standard" clock skew, us./tick */ int tickdelta; /* current clock skew, us. per tick */ long timedelta; /* unapplied time correction, us. */ long bigadj = 1000000; /* use 10x skew above bigadj us. */ struct adjtime_args { struct timeval *delta; struct timeval *olddelta; }; /* ARGSUSED */ int adjtime(p, uap, retval) struct proc *p; register struct adjtime_args *uap; register_t *retval; { struct timeval atv, oatv; register long ndelta; int s, error; if (error = suser(p->p_ucred, &p->p_acflag)) return (error); if(error = copyin((caddr_t)uap->delta, (caddr_t)&atv, sizeof (struct timeval))) return(error); ndelta = atv.tv_sec * 1000000 + atv.tv_usec; if (timedelta == 0) if (ndelta > bigadj) tickdelta = 10 * tickadj; else tickdelta = tickadj; if (ndelta % tickdelta) ndelta = ndelta / tickdelta * tickdelta; s = splclock(); if (uap->olddelta) { oatv.tv_sec = timedelta / 1000000; oatv.tv_usec = timedelta % 1000000; } timedelta = ndelta; splx(s); if (uap->olddelta) (void) copyout((caddr_t)&oatv, (caddr_t)uap->olddelta, sizeof (struct timeval)); return(0); } #define SECDAY ((unsigned)(24*60*60)) /* seconds per day */ #define SECYR ((unsigned)(365*SECDAY)) /* per common year */ #define YRREF 70 /* UNIX time referenced to 1970 */ /* * Initialze the time of day register. * Trust the RTC except for the case where it is set before * the UNIX epoch. In that case use the the UNIX epoch. * The argument passed in is ignored. */ void inittodr(base) time_t base; { /* * Initialize the calendar by * reading the BBC, if not already set. */ clock_initialize_calendar(); /* * The value returned by microtime() * is gotten from the calendar. */ microtime(&time); /* * This variable still exists to keep * 'w' happy. It should only be considered * an approximation. */ boottime.tv_sec = time.tv_sec; boottime.tv_usec = 0; /* * If the RTC does not have acceptable value, i.e. time before * the UNIX epoch, set it to the UNIX epoch */ if (time.tv_sec < 0) { printf ("WARNING: preposterous time in Real Time Clock"); time.tv_sec = 0; /* the UNIX epoch */ time.tv_usec = 0; setthetime(&time); boottime = time; printf(" -- CHECK AND RESET THE DATE!\n"); } return; } /* * Get value of an interval timer. The process virtual and * profiling virtual time timers are kept in the u. area, since * they can be swapped out. These are kept internally in the * way they are specified externally: in time until they expire. * * The real time interval timer is kept in the process table slot * for the process, and its value (it_value) is kept as an * absolute time rather than as a delta, so that it is easy to keep * periodic real-time signals from drifting. * * Virtual time timers are processed in the hardclock() routine of * kern_clock.c. The real time timer is processed by a timeout * routine, called from the softclock() routine. Since a callout * may be delayed in real time due to interrupt processing in the system, * it is possible for the real time timeout routine (realitexpire, given below), * to be delayed in real time past when it is supposed to occur. It * does not suffice, therefore, to reload the real timer .it_value from the * real time timers .it_interval. Rather, we compute the next time in * absolute time the timer should go off. */ struct getitimer_args { u_int which; struct itimerval *itv; }; /* ARGSUSED */ int getitimer(p, uap, retval) struct proc *p; register struct getitimer_args *uap; register_t *retval; { struct itimerval aitv; int s; if (uap->which > ITIMER_PROF) return(EINVAL); s = splclock(); if (uap->which == ITIMER_REAL) { /* * Convert from absoulte to relative time in .it_value * part of real time timer. If time for real time timer * has passed return 0, else return difference between * current time and time for the timer to go off. */ aitv = p->p_realtimer; if (timerisset(&aitv.it_value)) if (timercmp(&aitv.it_value, &time, <)) timerclear(&aitv.it_value); else timevalsub(&aitv.it_value, &time); } else aitv =p->p_stats->p_timer[uap->which]; splx(s); return(copyout((caddr_t)&aitv, (caddr_t)uap->itv, sizeof (struct itimerval))); } struct setitimer_args { u_int which; struct itimerval *itv; struct itimerval *oitv; }; /* ARGSUSED */ int setitimer(p, uap, retval) struct proc *p; register struct setitimer_args *uap; register_t *retval; { struct itimerval aitv; register struct itimerval *itvp; int s, error; if (uap->which > ITIMER_PROF) return(EINVAL); itvp = uap->itv; if (itvp && (error = copyin((caddr_t)itvp, (caddr_t)&aitv, sizeof(struct itimerval)))) return (error); if ((uap->itv = uap->oitv) && (error = getitimer(p, uap, retval))) return (error); if (itvp == 0) return (0); if (itimerfix(&aitv.it_value) || itimerfix(&aitv.it_interval)) return (EINVAL); s = splclock(); if (uap->which == ITIMER_REAL) { untimeout(realitexpire, (caddr_t)p); if (timerisset(&aitv.it_value)) { timevaladd(&aitv.it_value, &time); timeout(realitexpire, (caddr_t)p, hzto(&aitv.it_value)); } p->p_realtimer = aitv; } else p->p_stats->p_timer[uap->which] = aitv; splx(s); return(0); /* To insure good return value on success */ } /* * Real interval timer expired: * send process whose timer expired an alarm signal. * If time is not set up to reload, then just return. * Else compute next time timer should go off which is > current time. * This is where delay in processing this timeout causes multiple * SIGALRM calls to be compressed into one. */ void realitexpire(arg) void *arg; { register struct proc *p; int s; boolean_t funnel_state; funnel_state = thread_funnel_set(kernel_flock,TRUE); p = (struct proc *)arg; psignal(p, SIGALRM); if (!timerisset(&p->p_realtimer.it_interval)) { timerclear(&p->p_realtimer.it_value); (void) thread_funnel_set(kernel_flock, FALSE); return; } /* * If the time's way off, don't try to compensate by getting * there incrementally. */ s = splclock(); if (p->p_realtimer.it_value.tv_sec < time.tv_sec - 10) { p->p_realtimer.it_value = time; timeout(realitexpire, (caddr_t)p, hzto(&p->p_realtimer.it_value)); splx(s); (void) thread_funnel_set(kernel_flock, FALSE); return; } splx(s); for (;;) { s = splclock(); timevaladd(&p->p_realtimer.it_value, &p->p_realtimer.it_interval); if (timercmp(&p->p_realtimer.it_value, &time, >)) { timeout(realitexpire, (caddr_t)p, hzto(&p->p_realtimer.it_value)); splx(s); (void) thread_funnel_set(kernel_flock, FALSE); return; } splx(s); } (void) thread_funnel_set(kernel_flock, FALSE); } /* * Check that a proposed value to load into the .it_value or * .it_interval part of an interval timer is acceptable, and * fix it to have at least minimal value (i.e. if it is less * than the resolution of the clock, round it up.) */ int itimerfix(tv) struct timeval *tv; { if (tv->tv_sec < 0 || tv->tv_sec > 100000000 || tv->tv_usec < 0 || tv->tv_usec >= 1000000) return (EINVAL); if (tv->tv_sec == 0 && tv->tv_usec != 0 && tv->tv_usec < tick) tv->tv_usec = tick; return (0); } /* * Decrement an interval timer by a specified number * of microseconds, which must be less than a second, * i.e. < 1000000. If the timer expires, then reload * it. In this case, carry over (usec - old value) to * reducint the value reloaded into the timer so that * the timer does not drift. This routine assumes * that it is called in a context where the timers * on which it is operating cannot change in value. */ int itimerdecr(itp, usec) register struct itimerval *itp; int usec; { if (itp->it_value.tv_usec < usec) { if (itp->it_value.tv_sec == 0) { /* expired, and already in next interval */ usec -= itp->it_value.tv_usec; goto expire; } itp->it_value.tv_usec += 1000000; itp->it_value.tv_sec--; } itp->it_value.tv_usec -= usec; usec = 0; if (timerisset(&itp->it_value)) return (1); /* expired, exactly at end of interval */ expire: if (timerisset(&itp->it_interval)) { itp->it_value = itp->it_interval; itp->it_value.tv_usec -= usec; if (itp->it_value.tv_usec < 0) { itp->it_value.tv_usec += 1000000; itp->it_value.tv_sec--; } } else itp->it_value.tv_usec = 0; /* sec is already 0 */ return (0); } /* * Add and subtract routines for timevals. * N.B.: subtract routine doesn't deal with * results which are before the beginning, * it just gets very confused in this case. * Caveat emptor. */ void timevaladd(t1, t2) struct timeval *t1, *t2; { t1->tv_sec += t2->tv_sec; t1->tv_usec += t2->tv_usec; timevalfix(t1); } void timevalsub(t1, t2) struct timeval *t1, *t2; { t1->tv_sec -= t2->tv_sec; t1->tv_usec -= t2->tv_usec; timevalfix(t1); } void timevalfix(t1) struct timeval *t1; { if (t1->tv_usec < 0) { t1->tv_sec--; t1->tv_usec += 1000000; } if (t1->tv_usec >= 1000000) { t1->tv_sec++; t1->tv_usec -= 1000000; } } /* * Return the best possible estimate of the time in the timeval * to which tvp points. */ void microtime(struct timeval * tvp) { mach_timespec_t now = clock_get_calendar_value(); tvp->tv_sec = now.tv_sec; tvp->tv_usec = now.tv_nsec / NSEC_PER_USEC; }