| MICROTIME(9) | Kernel Developer's Manual | MICROTIME(9) | 
bintime, getbintime,
  microtime, getmicrotime,
  nanotime, getnanotime —
#include <sys/time.h>
void
  
  bintime(struct bintime *bt);
void
  
  getbintime(struct bintime
  *bt);
void
  
  microtime(struct timeval
  *tv);
void
  
  getmicrotime(struct timeval
    *tv);
void
  
  nanotime(struct timespec
  *tsp);
void
  
  getnanotime(struct timespec
    *tsp);
bintime() and getbintime()
  functions store the system time as a struct bintime at
  the addresses specified by bt. The
  microtime() and getmicrotime()
  functions perform the same utility, but record the time as a
  struct timeval instead. Similarly the
  nanotime() and getnanotime()
  functions store the time as a struct timespec. The
  structures are described in
  timeval(3).
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. Comparable functions exist to retrieve the time elapsed since boot; see microuptime(9).
microtime() 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.
| May 13, 2013 | NetBSD 9.3 |