Parallel task sink with kill signaling in Java

package guide;

import org.zeromq.SocketType;
import org.zeromq.ZMQ;
import org.zeromq.ZContext;

/**
* Task sink - design 2
* Adds pub-sub flow to send kill signal to workers
*/

public class tasksink2
{
public static void main(String[] args) throws Exception
{
// Prepare our context and socket
try (ZContext context = new ZContext()) {
ZMQ.Socket receiver = context.createSocket(SocketType.PULL);
receiver.bind("tcp://*:5558");

// Socket for worker control
ZMQ.Socket controller = context.createSocket(SocketType.PUB);
controller.bind("tcp://*:5559");

// Wait for start of batch
receiver.recv(0);

// Start our clock now
long tstart = System.currentTimeMillis();

// Process 100 confirmations
int task_nbr;
for (task_nbr = 0; task_nbr < 100; task_nbr++) {
receiver.recv(0);
if ((task_nbr / 10) * 10 == task_nbr) {
System.out.print(":");
}
else {
System.out.print(".");
}
System.out.flush();
}
// Calculate and report duration of batch
long tend = System.currentTimeMillis();

System.out.println(
"Total elapsed time: " + (tend - tstart) + " msec"
);

// Send the kill signal to the workers
controller.send("KILL", 0);

// Give it some time to deliver
Thread.sleep(1);
}
}
}