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MICROTIME(9)             BSD Kernel Developer's Manual            MICROTIME(9)

NAME
     microtime, getmicrotime, microuptime, getmicrouptime, nanotime,
     getnanotime, nanouptime, getnanouptime, bintime, binuptime -- system
     clock

SYNOPSIS
     #include <&lt;sys/time.h>&gt;

     void
     microtime(struct timeval *tv);

     void
     getmicrotime(struct timeval *tv);

     void
     microuptime(struct timeval *tv);

     void
     getmicrouptime(struct timeval *tv);

     void
     nanotime(struct timespec *tv);

     void
     getnanotime(struct timespec *tv);

     void
     nanouptime(struct timespec *tv);

     void
     getnanouptime(struct timespec *tv);

     void
     bintime(struct bintime *tv);

     void
     binuptime(struct bintime *tv);

DESCRIPTION
     This family of functions return the system clock in various different
     formats.  The functions with the "uptime" suffix return the monotonically
     increasing time since boot.  The functions without "up" return UTC time.
     The various formats for the result are specified with:

           bin    result in struct bintime containing seconds and 64-bit frac-
                  tions of seconds.

           nano   result in struct timespec containing seconds and nanoseconds

           micro  result in struct timeval containing seconds and microseconds

     The functions with the "get" prefix return a less precise result, but
     much faster.  They should be used where a precision of 10 msec is accept-
     able and where performance is critical.  The functions without the "get"
     prefix return the best timestamp that can be produced in the given for-
     mat.

CODE REFERENCES
     The implementation of these functions is partly machine dependent, but
     the bulk of the code is in the file sys/kern/kern_clock.c.

SEE ALSO
     settimeofday(2), hardclock(9), hz(9), inittodr(9), time(9)

BSD                              June 4, 2013                              BSD