NAME
binuptime,
getbinuptime, microuptime,
getmicrouptime, nanouptime,
getnanouptime —
get the time elapsed since
boot
SYNOPSIS
#include
<sys/time.h>
void
binuptime(struct
bintime *bt);
void
getbinuptime(struct
bintime *bt);
void
microuptime(struct
timeval *tv);
void
getmicrouptime(struct
timeval *tv);
void
nanouptime(struct
timespec *ts);
void
getnanouptime(struct
timespec *tsp);
DESCRIPTION
Thebinuptime()
and getbinuptime() functions store the time elapsed
since boot as a struct bintime at the address specified
by bt. The microuptime() and
getmicrouptime() functions perform the same utility,
but record the elapsed time as a struct timeval instead.
Similarly the nanouptime() and
getnanouptime() functions store the elapsed time as a
struct timespec. The used structures are described in
timeval(3).
The
binuptime(),
microuptime(),
and
nanouptime()
functions always query the timecounter to return the current time as
precisely as possible. Whereas getbinuptime(),
getmicrouptime(), and
getnanouptime() functions are abstractions which
return a less precise, but faster to obtain, time.
The intent of the
getbinuptime(),
getmicrouptime(),
and
getnanouptime()
functions is to enforce the user's preference for timer accuracy versus
execution time. They should be used where a precision of
1/HZ (e.g., 10 msec on a 100HZ machine,
see hz(9)) is acceptable or where performance is priority.
SEE ALSO
AUTHORS
This manual page was written by Kelly Yancey <kbyanc@posi.net>.