class Worker extends Thread {
	public Worker(Exchanger<String> ex) {
		this.ex = ex;
	}
	public void run() {
		String received = null;
		
		try {
			received = ex.exchange("World");
		} catch (InterruptedException e) {
			System.out.println("Worker interrupted :-(");
		}
		System.out.println("Worker received " + received + " in exchange for World");
		
		try {
			received = ex.exchange("Hi");
		} catch (InterruptedException e) {
			System.out.println("Worker interrupted :-(");
		}
		System.out.println("Worker received " + received.hashCode() + " in exchange for " + "Hi".hashCode());

	}

	private Exchanger<String> ex;
}

public class ExchangerTester {
	private static int N_EXCHANGES = 100;  // Set to larger number to test repeated exchange()'s
	public static void main(String[] args) {
		String received = null;
		Exchanger<String> exchanger = new Exchanger<String>();
		for (int i = 0; i < N_EXCHANGES; ++i) {
			new Worker(exchanger).start();

			try {
				received = exchanger.exchange("Hello");
			} catch (InterruptedException e) {
				System.out.println("Main thread interrupted :-(");
			}
			System.out.println("Main thread received " + received + " in exchange for Hello");

			try {
				Thread.sleep((long) (Math.random()*10));
			} catch (InterruptedException e) {
				// Being interrupted in a random sleep is still random, so nothing to do here
			}

			try {
				received = exchanger.exchange("Hi");
			} catch (InterruptedException e) {
				System.out.println("Main thread interrupted :-(");
			}
			System.out.println("Exchange #" + i + ": Main thread received " + received.hashCode() + " in exchange for " + "Hi".hashCode());
		}
}

}