class Noop {
	// Simplistic low-quality Marsaglia Shift-XOR pseudo-random number generator.
	// Bijective   
	// Cycle length for non-zero values is 4G-1.
	// 0 is absorbing and should be avoided -- fixed point.
	// The returned value is typically masked to produce a positive value.
	static volatile int Ticket = 0 ; 

	public static int nextRandom( int x ) {
		if (x == 0) { 
			// reseed the PRNG
			// Ticket is accessed infrequently and does not constitute a coherence hot-spot. 
			// Note that we use a non-atomic racy increment -- the race is rare and benign. 
			// If the race is a concern switch to an AtomicInteger.  
			// In addition accesses to the RW volatile global "Ticket"  variable are not 
			// (readily) predictable at compile-time so the JIT will not be able to elide 
			// nextRandom() invocations.  
			x = ++Ticket ; 
			if (x == 0) x = 1 ; 
		}
		x ^= x << 6;
		x ^= x >>> 21;
		x ^= x << 7;
		return x ;   
	}
}
class Monitor {
	private int x;
	public volatile Boolean go = false;
	public volatile Boolean go2 = false;
	public synchronized void call() {
		if ( x == 0 ) System.out.println(x);
		x = Noop.nextRandom( x );
	}
	Monitor() { x = Noop.nextRandom( x ); }
}
class T extends Thread {
	Monitor m;
	public void run() {
		m.go2 = true;
		while ( ! m.go );
		while ( m.go ) { m.call(); }
	}
	T( Monitor m ) { this.m = m; }
}
public class JavaThread {
	static int x = 2;

	static private int times = Integer.parseInt("10000000");

	public static void call( Monitor m ) throws InterruptedException {
		x = Noop.nextRandom( x );
		m.go = true;
		//while ( ! m.go2 );
		for ( int i = 0; i < times; i += 1 ) {
			m.call();
			x = Noop.nextRandom( x );
		}
		m.go = false;
	}
	public static void InnerMain() throws InterruptedException {
		Monitor m = new Monitor();
		T t = new T( m );
		t.start();
		long start = System.nanoTime();
		call( m );
		long end = System.nanoTime();
		System.out.println( (end - start) / times );
		t.join();
	}
	public static void main( String[] args ) throws InterruptedException {
		if ( args.length > 2 ) System.exit( 1 );
		if ( args.length == 2 ) { times = Integer.parseInt(args[1]); }

		if ( args.length > 2 ) System.exit( 1 );
		if ( args.length == 2 ) { times = Integer.parseInt(args[1]); }

		for ( int i = Integer.parseInt("5"); --i >= 0 ; ) { 
			InnerMain();
			// Thread.sleep(2000);	// 2 seconds
			x = Noop.nextRandom( x );
		}
		if ( x == 0 ) System.out.println(x);
	}
}

// Local Variables: //
// tab-width: 4 //
// End: //