import java.util.Arrays;
import java.util.Date;
import java.util.Random;

public class JvmPauseLatency {

    private static final int WARMUP = 20000;
    private static final int EXTRA = 15;
    private static final long PAUSE = 5 * 1000000000L; // in nanos

    private final Random rand = new Random();
    private int count;
    private double calculation;
    private final long[] results = new long[WARMUP + EXTRA];
    private long interval = 1; // in nanos

    private long busyPause(long pauseInNanos) {
        long until = System.nanoTime() + pauseInNanos;
        while(System.nanoTime() < until);
        return until;
    }

    public void run() {

// Warm up:
        busyPause(1);
        busyPause(PAUSE);

        long testDuration = ((WARMUP * 1) + (EXTRA * PAUSE)) / 1000000000L;
        System.out.println(new Date() +" => Please wait " + testDuration + " seconds for the results...");

        while(count < results.length) {
            if ((count & 7) > 0) interval = 0;

// No lag after first hiccup:
            long until = System.nanoTime() + interval;
            while(System.nanoTime() < until);
            double x = until;

// Yes lag hiccup after hiccup:
//            double x = busyPause(interval);

            long latency = System.nanoTime();
            latency = System.nanoTime() - latency;

            results[count++] = latency;
            interval = (count / WARMUP * (PAUSE - 1)) + 1; // it will change to PAUSE when it reaches WARMUP
        }

        // now print the last (EXTRA * 2) results so you can compare before and after the pause change (from 1 to PAUSE)
        System.out.println(new Date() + " => Calculation: " + calculation);
        System.out.println("Results:");
        long[] array = Arrays.copyOfRange(results, results.length - EXTRA * 2, results.length);
        for(long t: array) System.out.println(t);
    }

    public static void main(String[] args) {
        new JvmPauseLatency().run();
    }
}