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