| MICROUPTIME(9) | Kernel Developer's Manual | MICROUPTIME(9) |
binuptime,
getbinuptime, microuptime,
getmicrouptime, nanouptime,
getnanouptime — get the time
elapsed since boot
#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);
The
binuptime()
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.
This manual page was written by Kelly Yancey <kbyanc@posi.net>.
| June 8, 2010 | NetBSD 11.0 |