protected void sendGuardSignal() throws IOException {
final DatagramSocket guard;
final DatagramPacket guardPacket;
guard = new DatagramSocket();
guardPacket = new DatagramPacket(new byte[0], 0);
guardPacket.setSocketAddress(getLocalAddress());
guard.send(guardPacket);
guard.close();
}
// Broadcasts a packet containing server address to the LAN every second
public void run() {
try {
DatagramSocket socket = new DatagramSocket();
InetSocketAddress address = new InetSocketAddress("255.255.255.255", DISCOVERY_PORT);
byte[] message = new byte[0];
socket.setBroadcast(true);
DatagramPacket packet = new DatagramPacket(message, message.length);
packet.setSocketAddress(address);
while (true) {
socket.send(packet);
Thread.sleep(1000);
}
} catch (IOException e) {
// Port is in use, we don't know our own address or we could not send the broadcast for some
// reason. Either way, discovery won't work.
logger.log(Level.SEVERE, null, e);
} catch (InterruptedException e) {
logger.log(Level.INFO, "Discovery service shutting down");
}
}
@Override
public void run() {
// Open for voting
logger.log(Level.INFO, "Beginning voting");
voting.beginVoting();
VotingReceiver votingService = new VotingReceiver();
if (votingThread != null && !votingThread.isInterrupted()) {
votingThread.interrupt();
}
votingThread = new Thread(votingService);
votingThread.start();
try {
/*If client/server are on the same machine, broadcast may arrive at client
* before server opens receive socket. This is not relevant on separate machines
* but it avoids an extra voting cycle on single machine tests.
*/
Thread.sleep(200);
// Broadcast start of voting period
try {
DatagramSocket socket = new DatagramSocket();
InetSocketAddress address = new InetSocketAddress("255.255.255.255", VOTING_PORT);
byte[] message = new byte[0];
socket.setBroadcast(true);
DatagramPacket packet = new DatagramPacket(message, message.length);
packet.setSocketAddress(address);
socket.send(packet);
} catch (IOException e) {
logger.log(Level.SEVERE, null, e);
}
Thread.sleep(10000); // Run voting for 10 seconds
} catch (InterruptedException ex) {
logger.log(Level.INFO, "Voting shutting down");
}
votingThread.interrupt();
voting.endVoting(MCServer.this);
}