Java RMI test

Main.java

import java.io.Serializable;
import java.rmi.Remote;
import java.rmi.RemoteException;
import java.rmi.registry.LocateRegistry;
import java.rmi.registry.Registry;
import java.rmi.server.UnicastRemoteObject;
import java.util.Arrays;

public class Main {

	private static final String name = "name";

	public static final void main(String args[]) throws Exception {
		new Main().run();
		System.exit(0);
	}

	private Registry registry;

	void run() throws Exception {
		registry = LocateRegistry.createRegistry(Registry.REGISTRY_PORT);

		debug("UnicastRemoteObject", false, "getRegistry", false);
		server0();
		client0();
		client0();
		debug("UnicastRemoteObject", true, "getRegistry", false);
		server1();
		client0();
		client0();
		debug("UnicastRemoteObject", false, "getRegistry", true);
		server0();
		client1();
		client1();
		debug("UnicastRemoteObject", true, "getRegistry", true);
		server1();
		client1();
		client1();
	}

	void server0() throws Exception {
		registry.rebind(name, new RMITest());
	}

	void server1() throws Exception {
		/**
		 * java.rmi.NoSuchObjectException: no such object in table
		 * 頻出して安定しない
		 */
		registry.rebind(name, UnicastRemoteObject.exportObject(new RMITest(), 0));
	}

	void client0() throws Exception {
		Remote remote = registry.lookup(name);
		if (remote instanceof RMI) {
			System.out.println(((RMI) remote).calc());
		}
	}

	void client1() throws Exception {
		Remote remote = LocateRegistry.getRegistry().lookup(name);
		if (remote instanceof RMI) {
			System.out.println(((RMI) remote).calc());
		}
	}

	void debug(Object... o) {
		System.out.println(Arrays.deepToString(o));
	}
}

interface RMI extends Remote {
	int calc() throws RemoteException;
}

class RMITest implements RMI, Serializable {

	private static final long serialVersionUID = 4023010035712853564L;

	private int x = 0;

	@Override
	public int calc() throws RemoteException {
		return x++;
	}
}

UnicastRemoteObjectが実行毎で失敗したりする原因がよく分からない