Java high precision stopwatch

Question

I have this problem, and I can't get any idea how to solve it.
I have to measure the time needed to perform certain function. Okay, stopwatch function that measure time in milliseconds wasn't good enough, so I used measurement in nano seconds.

The problem is, function ends so fast, even stopwatch in nano seconds can't measure it.

I know that stopwatch works, because I tried to put for example Thread.sleep(1) in my function (Thread.sleep is in milliseconds), and I get my time, but without Thread.sleep, my time is always 0. Any ideas?

Here is my code:

long startTimeLocalNS=0;
long stopTimeLocalNS = 0;
startTimeLocalNS = System.nanoTime();
if (something)
{
    /*my Code;*/
}   
stopTimeLocalNS = System.nanoTime();
disconnectTime = (stopTimeLocalNS - startTimeLocalNS);

Answer 1

How about running the function a few thousand (or million) times in a loop, measuring the total time and dividing it by the number of iterations?

But beware the many pitfalls in writing microbenchmarks.