MICROUPTIME(9) | Kernel Developer's Manual | MICROUPTIME(9) |
binuptime
, getbinuptime
,
microuptime
, getmicrouptime
,
nanouptime
, getnanouptime
—
#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);
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.
June 8, 2010 | NetBSD 9.0 |