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
)
)
and
getbinuptime(
)
functions store the time elapsed since boot as a
at the address specified by
bt
.
The
microuptime(
)
and
getmicrouptime(
)
functions perform the same utility, but record the elapsed time as a
instead.
Similarly the
nanouptime(
)
and
getnanouptime(
)
functions store the elapsed time as a
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.