-/* kern_time.c 5.3 82/09/04 */
+/* kern_time.c 5.16 83/06/10 */
+
+#include "../machine/reg.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"
+/*
+ * 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 {
struct timezone *tzp;
} *uap = (struct a *)u.u_ap;
struct timeval atv;
+ int s;
- microtime(&atv);
- if (copyout((caddr_t)&atv, (caddr_t)uap->tp, sizeof (atv))) {
- u.u_error = EFAULT;
+ s = spl7(); atv = time; splx(s);
+ u.u_error = copyout((caddr_t)&atv, (caddr_t)uap->tp, sizeof (atv));
+ if (u.u_error)
return;
- }
if (uap->tzp == 0)
return;
- if (copyout((caddr_t)&tz, uap->tzp, sizeof (tz))) {
- u.u_error = EFAULT;
- return;
- }
+ /* SHOULD HAVE PER-PROCESS TIMEZONE */
+ u.u_error = copyout((caddr_t)&tz, (caddr_t)uap->tzp, sizeof (tz));
}
settimeofday()
{
register struct a {
- struct timeval *tv;
- struct timezone *tzp;
+ struct timeval *tv;
+ struct timezone *tzp;
} *uap = (struct a *)u.u_ap;
struct timeval atv;
struct timezone atz;
- if (copyin((caddr_t)uap->tv, (caddr_t)&atv, sizeof (struct timeval))) {
- u.u_error = EFAULT;
+ u.u_error = copyin((caddr_t)uap->tv, (caddr_t)&atv,
+ sizeof (struct timeval));
+ if (u.u_error)
return;
- }
- if (suser()) {
- struct timeval tdelta;
-
- tdelta = atv;
-
- timevalsub(&tdelta, &time);
- timevaladd(&boottime, &tdelta);
- time = atv;
- clockset();
- }
- if (uap->tzp) {
- if (copyin((caddr_t)uap->tzp, (caddr_t)&atz, sizeof (atz))) {
- u.u_error = EFAULT;
+ setthetime(&atv);
+ if (uap->tzp && suser()) {
+ u.u_error = copyin((caddr_t)uap->tzp, (caddr_t)&atz,
+ sizeof (atz));
+ if (u.u_error)
return;
- }
- /* XXX */
}
}
-timevaladd(t1, t2)
- struct timeval *t1, *t2;
-{
-
- t1->tv_sec += t2->tv_sec;
- t1->tv_usec += t2->tv_sec;
- timevalfix(t1);
-}
-
-timevalsub(t1, t2)
- struct timeval *t1, *t2;
-{
-
- t1->tv_sec -= t2->tv_sec;
- t1->tv_usec -= t2->tv_sec;
- timevalfix(t1);
-}
-
-timevalfix(t1)
- struct timeval *t1;
+setthetime(tv)
+ struct timeval *tv;
{
+ int s;
- if (t1->tv_usec < 0) {
- t1->tv_sec--;
- t1->tv_usec += 1000000;
- }
- if (t1->tv_usec >= 1000000) {
- t1->tv_sec++;
- t1->tv_usec -= 1000000;
- }
+ if (!suser())
+ return;
+/* WHAT DO WE DO ABOUT PENDING REAL-TIME TIMEOUTS??? */
+ boottime.tv_sec += tv->tv_sec - time.tv_sec;
+ s = spl7(); time = *tv; splx(s);
+ resettodr();
}
+/*
+ * 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.
+ */
getitimer()
{
register struct a {
u_int which;
struct itimerval *itv;
} *uap = (struct a *)u.u_ap;
- register struct itimerval *itp;
+ struct itimerval aitv;
int s;
if (uap->which > 2) {
u.u_error = EINVAL;
return;
}
- if (uap->which == ITIMER_REAL)
- itp = &u.u_procp->p_realtimer;
- else
- itp = &u.u_timer[uap->which];
s = spl7();
- if (copyout((caddr_t)itp, uap->itv, sizeof (struct itimerval))) {
- u.u_error = EFAULT;
- goto bad;
- }
-bad:
+ 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 = u.u_procp->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 = u.u_timer[uap->which];
+ splx(s);
+ u.u_error = copyout((caddr_t)&aitv, (caddr_t)uap->itv,
+ sizeof (struct itimerval));
splx(s);
}
{
register struct a {
u_int which;
- struct itimerval *itv;
+ struct itimerval *itv, *oitv;
} *uap = (struct a *)u.u_ap;
struct itimerval aitv;
int s;
+ register struct proc *p = u.u_procp;
- s = spl7();
if (uap->which > 2) {
u.u_error = EINVAL;
- goto bad;
+ return;
+ }
+ u.u_error = copyin((caddr_t)uap->itv, (caddr_t)&aitv,
+ sizeof (struct itimerval));
+ if (u.u_error)
+ return;
+ if (uap->oitv) {
+ uap->itv = uap->oitv;
+ getitimer();
}
- if (copyin((caddr_t)uap->itv, (caddr_t)&aitv,
- sizeof (struct itimerval))) {
- u.u_error = EFAULT;
- goto bad;
+ if (itimerfix(&aitv.it_value) || itimerfix(&aitv.it_interval)) {
+ u.u_error = EINVAL;
+ return;
}
- u.u_timer[uap->which] = aitv;
- if (uap->which == ITIMER_REAL)
- u.u_procp->p_realtimer = aitv;
-bad:
+ s = spl7();
+ 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
+ u.u_timer[uap->which] = aitv;
splx(s);
- return;
}
-getandsetitimer()
+/*
+ * 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 = spl7();
+ int s;
- getitimer();
- if (u.u_error == 0) {
- u.u_ap[1] = u.u_ap[2];
- setitimer();
+ psignal(p, SIGALRM);
+ if (!timerisset(&p->p_realtimer.it_interval)) {
+ timerclear(&p->p_realtimer.it_value);
+ return;
+ }
+ for (;;) {
+ s = spl7();
+ 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);
+ return;
+ }
+ splx(s);
}
- splx(s);
}
+/*
+ * 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;
+{
+
+ 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.
+ */
itimerdecr(itp, usec)
register struct itimerval *itp;
int usec;
{
- while (itp->itimer_value.tv_usec < usec) {
- if (itp->itimer_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;
- itp->itimer_value.tv_usec += 1000000;
- itp->itimer_value.tv_sec--;
+ }
+ itp->it_value.tv_usec += 1000000;
+ itp->it_value.tv_sec--;
}
- itp->itimer_value.tv_usec -= usec;
- if (timerisset(&itp->itimer_value))
+ itp->it_value.tv_usec -= usec;
+ usec = 0;
+ if (timerisset(&itp->it_value))
return (1);
+ /* expired, exactly at end of interval */
expire:
- if (itp->itimer_reload == 0)
- itp->itimer_value.tv_usec = 0;
- else
- itp->itimer_value = itp->itimer_interval;
+ 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);
}
-#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);
}
-#include "../h/timeb.h"
+timevalsub(t1, t2)
+ struct timeval *t1, *t2;
+{
-oftime()
+ t1->tv_sec -= t2->tv_sec;
+ t1->tv_usec -= t2->tv_usec;
+ timevalfix(t1);
+}
+
+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;
+ }
}