void
bintime(
struct bintime *bt
)
void
getbintime(
struct bintime *bt
)
void
microtime(
struct timeval *tv
)
void
getmicrotime(
struct timeval *tv
)
void
nanotime(
struct timespec *ts
)
void
getnanotime(
struct timespec *tsp
)
)
and
getbintime(
)
functions store the system time as a
at the addresses specified by
bt
.
The
microtime(
)
and
getmicrotime(
)
functions perform the same utility, but record the time as a
instead.
Similarly the
nanotime(
)
and
getnanotime(
)
functions store the time as a
The
bintime(),
microtime(
),
and
nanotime(
)
functions
always query the timecounter to return the current time as precisely as
possible.
Whereas
getbintime(
),
getmicrotime(
),
and
getnanotime(
)
functions are abstractions which return a less precise, but
faster to obtain, time.
The intent of the
getbintime(),
getmicrotime(
),
and
getnanotime(
)
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.
The system realtime clock is guaranteed to be monotonically increasing at all times. As such, all calls to these functions are guaranteed to return a system time greater than or equal to the system time returned in any previous calls.
)
family of functions is in
sys/kern/kern_tc.c
as a part of the
timecounter(9)
framework.
The implementation of the time counter sources used by the timecounter(9) is machine dependent, hence its location in the source code tree varies from architecture to architecture.