NAME    [Toc]    [Back]

     hardclock - real-time system clock

SYNOPSIS    [Toc]    [Back]

     #include <sys/systm.h>

     void
     hardclock(struct clockframe *frame);

DESCRIPTION    [Toc]    [Back]

     hardclock() implements the real-time  system  clock,  interrupting hz(9)
     times  a  second.   The argument frame is an opaque, machine
dependent
     structure that encapsulates the previous machine state.

     hardclock() performs a variety of time related  housekeeping
tasks, such
     as

           +o    If  the  current process has virtual or profiling
interval
               timers, update the timers and deliver  appropriate
signals.

           +o    If there is no separate statistics clock, execute
statclock().

           +o   Increment the time of day,  implementing  any  adjustments requested
  by  adjtime(2) or required as a result of
running an NTP
               daemon or other configured external clock.

           +o    Update  the  real-time  timeout  queue,   calling
softclock() directly
  if  the  current  interrupt  priority  is  low
enough.

SEE ALSO    [Toc]    [Back]

     adjtime(2), hz(9), microtime(9), spl(9), time(9), timeout(9)

CODE REFERENCES    [Toc]    [Back]

     hardclock()      is      implemented     in     the     file
sys/kern/kern_clock.c.

OpenBSD     3.6                           July      14,      2001