Measures the maximum observed drift between the millisecond timer and the nano timer (which will usually be provided by Time Stamp Counter). Src - "The Well-Grounded Java Developer" (Listing 6.1, pg. 165), see related post on java simon google group http://goo.gl/GL4qOR

App

package uk.me.nvt.PerformanceNanoTimeDrift;

/**
 * Measures the maximum observed drift between the millisecond timer and the nano timer 
 * (which will usually be provided by Time Stamp Counter). 
 * Src - "The Well-Grounded Java Developer" (Listing 6.1, pg. 165)
 */
public class App {
  public static void main(String[] args) {
		System.out.println("Hello World!");
		runWithSpin(args);
	}

	private static void runWithSpin(String[] args) {
		long nowNanos = 0, startNanos = 0;
		long startMillis = System.currentTimeMillis(), nowMillis = startMillis;
		int count = 0;
		while (startMillis == nowMillis) { // runs at least once, until millisecond has increased
			startNanos = System.nanoTime();
			nowMillis = System.currentTimeMillis();
			++ count;
		}
		System.out.println("Number of cycles until millisecond increase "+count);
		startMillis = nowMillis; // reset startMillis to increment millisecond
		double maxDrift = 0;
		long lastMillis;
		while (true) {
			lastMillis = nowMillis;
			while (nowMillis - lastMillis < 1000) { // while difference between current and previous is less than 1000
				nowNanos = System.nanoTime();
				nowMillis = System.currentTimeMillis();
			}
			long durationMillis = nowMillis - startMillis;
			// difference between nanotime (TSC) and millisecond wall clock
			double driftNanos = 1000000 * (((double) (nowNanos - startNanos)) / 1000000 - durationMillis);
			if (Math.abs(driftNanos) > maxDrift) {
				System.out.println("Now - Start = " + durationMillis
						+ " driftNanos = " + driftNanos);
				maxDrift = Math.abs(driftNanos);
			}
		}
	}
}