hpux man page for gethrtime

gethrtime(3C)															     gethrtime(3C)

NAME
       gethrtime() - get high resolution time

SYNOPSIS
DESCRIPTION
       The  function  returns the current high-resolution real time.  Time is expressed as nanoseconds since a certain time in the past.  This API
       uses a fast light weight system call to get the nanoseconds from a certain time.  It is not correlated in any way to the time of day.  This
       API is used for performance measurement tasks and is used for cheap and accurate interval timing.

       is a signed 64-bit number.

RETURN VALUE
       Upon successful completion, returns a number of nanoseconds.  Otherwise, a value of -1 is returned.

WARNINGS
       This  API  will	only  be available if the application is being compiled in -Ae mode (extended ANSI) because 64-bit integer numbers are not
       available in -Aa (ANSI) mode. Please refer to cc(1).

EXAMPLES
       The following code fragment measures the average cost of

	    hrtime_t begin, end;

	    int i, count = 1000;

	    begin = gethrtime();

	    for (i = 0; i < count; i++)

		    getgid();

	    end = gethrtime();

	    printf("Avg getgid() time = %lld nsec", (end - begin)/count );

																     gethrtime(3C)