BSD 4_3_Net_2 release

[unix-history] / usr / src / sys / kern / kern_time.c

diff --git a/usr/src/sys/kern/kern_time.c b/usr/src/sys/kern/kern_time.c
index 30ba980..e5291f2 100644 (file)
--- a/usr/src/sys/kern/kern_time.c
+++ b/usr/src/sys/kern/kern_time.c
@@ -1,177 +1,259 @@
-/*     kern_time.c     5.5     82/09/08        */
+/*
+ * Copyright (c) 1982, 1986, 1989 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 7.15 (Berkeley) 3/17/91
+ */
+
+#include "param.h"
+#include "resourcevar.h"
+#include "kernel.h"
+#include "proc.h"

 
 

-#include "../h/param.h"
-#include "../h/dir.h"          /* XXX */
-#include "../h/user.h"
-#include "../h/kernel.h"
-#include "../h/reg.h"
-#include "../h/inode.h"
-#include "../h/proc.h"
+#include "machine/cpu.h"

 
 /* 
  * Time of day and interval timer support.
 
 /* 
  * 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.

  */
 
  */
 

-gettimeofday()
-{
-       register struct a {
+/* ARGSUSED */
+gettimeofday(p, uap, retval)
+       struct proc *p;
+       register struct args {

                struct  timeval *tp;
                struct  timezone *tzp;
                struct  timeval *tp;
                struct  timezone *tzp;

-       } *uap = (struct a *)u.u_ap;
+       } *uap;
+       int *retval;
+{

        struct timeval atv;
        struct timeval atv;

-       int s;
+       int error = 0;

 
 

-       s = spl7(); atv = time; splx(s);
-       if (copyout((caddr_t)&atv, (caddr_t)uap->tp, sizeof (atv))) {
-               u.u_error = EFAULT;
-               return;
-       }
-       if (uap->tzp == 0)
-               return;
-       /* SHOULD HAVE PER-PROCESS TIMEZONE */
-       if (copyout((caddr_t)&tz, uap->tzp, sizeof (tz))) {
-               u.u_error = EFAULT;
-               return;
+       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);

 }
 
 }
 

-settimeofday()
-{
-       register struct a {
+/* ARGSUSED */
+settimeofday(p, uap, retval)
+       struct proc *p;
+       struct args {

                struct  timeval *tv;
                struct  timezone *tzp;
                struct  timeval *tv;
                struct  timezone *tzp;

-       } *uap = (struct a *)u.u_ap;
+       } *uap;
+       int *retval;
+{

        struct timeval atv;
        struct timezone atz;
        struct timeval atv;
        struct timezone atz;

+       int error, s;

 
 

-       if (copyin((caddr_t)uap->tv, (caddr_t)&atv, sizeof (struct timeval))) {
-               u.u_error = EFAULT;
-               return;
-       }
-       setthetime(&atv);
-       if (uap->tzp && suser()) {
-               if (copyin((caddr_t)uap->tzp, (caddr_t)&atz, sizeof (atz))) {
-                       u.u_error = EFAULT;
-                       return;
-               }
+       if (error = suser(p->p_ucred, &p->p_acflag))
+               return (error);
+       if (uap->tv) {
+               if (error = copyin((caddr_t)uap->tv, (caddr_t)&atv,
+                   sizeof (struct timeval)))
+                       return (error);
+               /* WHAT DO WE DO ABOUT PENDING REAL-TIME TIMEOUTS??? */
+               boottime.tv_sec += atv.tv_sec - time.tv_sec;
+               s = splhigh(); time = atv; splx(s);
+               resettodr();

        }
        }

+       if (uap->tzp && (error = copyin((caddr_t)uap->tzp, (caddr_t)&atz,
+           sizeof (atz))) == 0)
+               tz = atz;
+       return (error);

 }
 
 }
 

-setthetime(tv)
-       struct timeval *tv;
-{
-       register int delta;
-       int s;
+extern int tickadj;                    /* "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. */

 
 

-       if (!suser())
-               return;
-       boottime.tv_sec += tv->tv_sec - time.tv_sec;
-       s = spl7(); time = *tv; splx(s);
-       clockset();
-}
-
-timevaladd(t1, t2)
-       struct timeval *t1, *t2;
-{
-
-       t1->tv_sec += t2->tv_sec;
-       t1->tv_usec += t2->tv_usec;
-       timevalfix(t1);
-}
-
-timevalsub(t1, t2)
-       struct timeval *t1, *t2;
+/* ARGSUSED */
+adjtime(p, uap, retval)
+       struct proc *p;
+       register struct args {
+               struct timeval *delta;
+               struct timeval *olddelta;
+       } *uap;
+       int *retval;

 {
 {

+       struct timeval atv, oatv;
+       register long ndelta;
+       int s, error;

 
 

-       t1->tv_sec -= t2->tv_sec;
-       t1->tv_usec -= t2->tv_usec;
-       timevalfix(t1);
-}
+       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 / tickadj * tickadj;

 
 

-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;
+       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);

 }
 
 }
 

-getitimer()
-{
-       register struct a {
+/*
+ * Get value of an interval timer.  The process virtual and
+ * profiling virtual time timers are kept in the p_stats 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.
+ */
+/* ARGSUSED */
+getitimer(p, uap, retval)
+       struct proc *p;
+       register struct args {

                u_int   which;
                struct  itimerval *itv;
                u_int   which;
                struct  itimerval *itv;

-       } *uap = (struct a *)u.u_ap;
+       } *uap;
+       int *retval;
+{

        struct itimerval aitv;
        int s;
 
        struct itimerval aitv;
        int s;
 

-       if (uap->which > 2) {
-               u.u_error = EINVAL;
-               return;
-       }
-       s = spl7();
+       if (uap->which > ITIMER_PROF)
+               return (EINVAL);
+       s = splclock();

        if (uap->which == ITIMER_REAL) {
        if (uap->which == ITIMER_REAL) {

-               aitv = u.u_procp->p_realtimer;
+               /*
+                * 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
                if (timerisset(&aitv.it_value))
                        if (timercmp(&aitv.it_value, &time, <))
                                timerclear(&aitv.it_value);
                        else
                                timevalsub(&aitv.it_value, &time);
        } else

-               aitv = u.u_timer[uap->which];
-       splx(s);
-       if (copyout((caddr_t)&aitv, uap->itv, sizeof (struct itimerval)))
-               u.u_error = EFAULT;
+               aitv = p->p_stats->p_timer[uap->which];

        splx(s);
        splx(s);

+       return (copyout((caddr_t)&aitv, (caddr_t)uap->itv,
+           sizeof (struct itimerval)));

 }
 
 }
 

-setitimer()
-{
-       register struct a {
+/* ARGSUSED */
+setitimer(p, uap, retval)
+       struct proc *p;
+       register struct args {

                u_int   which;
                struct  itimerval *itv, *oitv;
                u_int   which;
                struct  itimerval *itv, *oitv;

-       } *uap = (struct a *)u.u_ap;
+       } *uap;
+       int *retval;
+{

        struct itimerval aitv;
        struct itimerval aitv;

-       int s;
-       register struct proc *p = u.u_procp;
+       register struct itimerval *itvp;
+       int s, error;

 
 

-       if (uap->which > 2) {
-               u.u_error = EINVAL;
-               return;
-       }
-       if (copyin((caddr_t)uap->itv, (caddr_t)&aitv,
-           sizeof (struct itimerval))) {
-               u.u_error = EFAULT;
-               return;
-       }
-       if (uap->oitv) {
-               uap->itv = uap->oitv;
-               getitimer();
-       }
-       if (itimerfix(&aitv.it_value) || itimerfix(&aitv.it_interval)) {
-               u.u_error = EINVAL;
-               return;
-       }
-       s = spl7();
+       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) {
        if (uap->which == ITIMER_REAL) {

-               untimeout(unrto, p);
+               untimeout(realitexpire, (caddr_t)p);

                if (timerisset(&aitv.it_value)) {
                        timevaladd(&aitv.it_value, &time);
                if (timerisset(&aitv.it_value)) {
                        timevaladd(&aitv.it_value, &time);

-                       timeout(unrto, p, hzto(&aitv.it_value));
+                       timeout(realitexpire, (caddr_t)p, hzto(&aitv.it_value));

                }
                p->p_realtimer = aitv;
        } else
                }
                p->p_realtimer = aitv;
        } else

-               u.u_timer[uap->which] = aitv;
+               p->p_stats->p_timer[uap->which] = aitv;

        splx(s);
        splx(s);

+       return (0);

 }
 
 }
 

-unrto(p)
+/*
+ * 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.
+ */
+realitexpire(p)

        register struct proc *p;
 {
        int s;
        register struct proc *p;
 {
        int s;


@@ -182,11 +264,12 @@ unrto(p)
                return;
        }
        for (;;) {
                return;
        }
        for (;;) {

-               s = spl7();
+               s = splclock();

                timevaladd(&p->p_realtimer.it_value,
                    &p->p_realtimer.it_interval);
                if (timercmp(&p->p_realtimer.it_value, &time, >)) {
                timevaladd(&p->p_realtimer.it_value,
                    &p->p_realtimer.it_interval);
                if (timercmp(&p->p_realtimer.it_value, &time, >)) {

-                       timeout(unrto, p, hzto(&p->p_realtimer.it_value));
+                       timeout(realitexpire, (caddr_t)p,
+                           hzto(&p->p_realtimer.it_value));

                        splx(s);
                        return;
                }
                        splx(s);
                        return;
                }


@@ -194,6 +277,12 @@ unrto(p)
        }
 }
 
        }
 }
 

+/*
+ * 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.)
+ */

 itimerfix(tv)
        struct timeval *tv;
 {
 itimerfix(tv)
        struct timeval *tv;
 {


@@ -201,11 +290,21 @@ itimerfix(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_sec > 100000000 ||
            tv->tv_usec < 0 || tv->tv_usec >= 1000000)
                return (EINVAL);

-       if (tv->tv_sec == 0 && tv->tv_usec < tick)
+       if (tv->tv_sec == 0 && tv->tv_usec != 0 && tv->tv_usec < tick)

                tv->tv_usec = tick;
        return (0);
 }
 
                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.
+ */

 itimerdecr(itp, usec)
        register struct itimerval *itp;
        int usec;
 itimerdecr(itp, usec)
        register struct itimerval *itp;
        int usec;


@@ -213,6 +312,7 @@ itimerdecr(itp, usec)
 
        if (itp->it_value.tv_usec < usec) {
                if (itp->it_value.tv_sec == 0) {
 
        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;
                }
                        usec -= itp->it_value.tv_usec;
                        goto expire;
                }


@@ -223,6 +323,7 @@ itimerdecr(itp, usec)
        usec = 0;
        if (timerisset(&itp->it_value))
                return (1);
        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;
 expire:
        if (timerisset(&itp->it_interval)) {
                itp->it_value = itp->it_interval;


@@ -232,46 +333,45 @@ expire:
                        itp->it_value.tv_sec--;
                }
        } else
                        itp->it_value.tv_sec--;
                }
        } else

-               itp->it_value.tv_usec = 0;
+               itp->it_value.tv_usec = 0;              /* sec is already 0 */

        return (0);
 }
 
        return (0);
 }
 

-#ifndef NOCOMPAT
-otime()
+/*
+ * 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.
+ */
+timevaladd(t1, t2)
+       struct timeval *t1, *t2;

 {
 
 {
 

-       u.u_r.r_time = time.tv_sec;
+       t1->tv_sec += t2->tv_sec;
+       t1->tv_usec += t2->tv_usec;
+       timevalfix(t1);

 }
 
 }
 

-ostime()
+timevalsub(t1, t2)
+       struct timeval *t1, *t2;

 {
 {

-       register struct a {
-               int     time;
-       } *uap = (struct a *)u.u_ap;
-       struct timeval tv;

 
 

-       tv.tv_sec = uap->time;
-       tv.tv_usec = 0;
-       setthetime(&tv);
+       t1->tv_sec -= t2->tv_sec;
+       t1->tv_usec -= t2->tv_usec;
+       timevalfix(t1);

 }
 
 }
 

-#include "../h/timeb.h"
-
-oftime()
+timevalfix(t1)
+       struct timeval *t1;

 {
 {

-       register struct a {
-               struct  timeb   *tp;
-       } *uap;
-       struct timeb t;

 
 

-       uap = (struct a *)u.u_ap;
-       (void) spl7();
-       t.time = time.tv_sec;
-       t.millitm = time.tv_usec / 1000;
-       (void) spl0();
-       t.timezone = tz.tz_minuteswest;
-       t.dstflag = tz.tz_dsttime;
-       if (copyout((caddr_t)&t, (caddr_t)uap->tp, sizeof(t)) < 0)
-               u.u_error = EFAULT;
+       if (t1->tv_usec < 0) {
+               t1->tv_sec--;
+               t1->tv_usec += 1000000;
+       }
+       if (t1->tv_usec >= 1000000) {
+               t1->tv_sec++;
+               t1->tv_usec -= 1000000;
+       }

 }
 }

-#endif