gistfile1.java

public class Volatility {

	static int NEXT_IN_LINE = 0;

	public static void main(String[] args) throws Exception {
		new CustomerInLine().start();
		new Queue().start();
	}

	static class CustomerInLine extends Thread {
		@Override
		public void run() {
			while (true) {
				if (NEXT_IN_LINE >= 4) {
					break;
				}
			}
			System.out.format("Great, finally #%d was called, now it is my turn\n",NEXT_IN_LINE);
		}
	}

	static class Queue extends Thread {
		@Override
		public void run() {
			while (NEXT_IN_LINE < 11) {
				System.out.format("Calling for the customer #%d\n", NEXT_IN_LINE++);
				try {
					Thread.sleep(200);
				} catch (InterruptedException e) {
					e.printStackTrace();
				}
			}
		}
	}
}