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


NAME

     microtime, getmicrotime, nanotime, getnanotime -- get the current time


SYNOPSIS

     #include <sys/time.h>

     void
     microtime(struct timeval *tv);

     void
     getmicrotime(struct timeval *tv);

     void
     nanotime(struct timespec *ts);

     void
     getnanotime(struct timespec *tsp);


DESCRIPTION

     The microtime() and getmicrotime() functions stores the system time as a
     struct timeval at the address specified by tv.  The nanotime() and
     getnanotime() functions perform the same utility, but record the time as
     a struct timespec instead.

     Microtime() and nanotime() always query the timecounter to return the
     current time as precisely as possible.  Whereas getmicrotime() and
     getnanotime() functions are abstractions which return a less precise, but
     faster to obtain, time.  The getmicrouptime() and getnanouptime()
     functions will return a time which is up to 1/HZ previous to the call.

     The intent of the getmicrotime() and getnanotime() functions is to
     enforce the user's preference for timer accuracy versus execution time.


SEE ALSO

     getmicrouptime(9), getnanouptime(9), microuptime(9), nanouptime(9),
     tvtohz(9)


HISTORY

     The microtime and nanotime functions first appeared in FreeBSD 3.0 but
     existed in other incarnations since 4.4BSD


AUTHORS

     This manual page was written by Kelly Yancey <kbyanc@posi.net>.

DragonFly 4.9                 September 23, 2017                 DragonFly 4.9

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