NetBSD-5.0.2/share/man/man9/hardclock.9

.\"	$NetBSD: hardclock.9,v 1.2 2008/04/30 13:10:58 martin Exp $
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.\" by Thomas Klausner.
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.Dd September 5, 2001
.Dt HARDCLOCK 9
.Os
.Sh NAME
.Nm hardclock
.Nd real-time timer
.Sh SYNOPSIS
.Ft void
.Fn hardclock "struct clockframe *"
.Sh DESCRIPTION
The
.Fn hardclock
function gets called
.Xr hz 9
times per second.
It performs different tasks:
.Bl -bullet -compact
.It
Run the current process's virtual and profile time (decrease the
corresponding timers, if they are activated, and generate
.Li SIGVTALRM
or
.Li SIGPROF ,
respectively).
.It
Increment the time-of-day, taking care of any
.Xr ntpd 8
or
.Xr adjtime 2
induced changes and leap seconds, as well as any necessary
compensations to keep in sync with PPS signals or external clocks, if
support for this is in the kernel (see
.Xr options 4 ) .
.It
Schedule softclock interrupts if any callouts should be triggered (see
.Xr callout 9 ) .
.El
.Sh SEE ALSO
.Xr adjtime 2 ,
.Xr ntp_adjtime 2 ,
.Xr signal 7 ,
.Xr ntpd 8 ,
.Xr callout 9 ,
.Xr hz 9