NIO: Selector stopper block i select()

Jeg har et "sjovt" problem med Selector. Min multiplayer-server anvender multiplexed, non-blocking I/O med NIO - og følgende metode start() køres af en single-instance tråd. En anden tråd en Selector'ens accepterer inkommende klienter.

Hvis jeg connecter 50 klienter (eller bare 10) går al kommunikation perfekt, men knap 1 sekund efter klienterne disconnecter (på samme tid), begynder Selector'en at loope (blokkerer ikke længere i select()) og bruger derfor 100% CPU. De følgende linier printes derfor kontinuerligt til konsollen og fylder 20 mb i log-filen på under 10 sekunder:

* Selector: out of select(30000)
* Selector: continue

private void start() {
  Log.echoSystem("ClientHandler: started");
  try {
    selector = Selector.open();
    int keysAdded;
    while (noStopRequested) {
      SelectionKey key = null;
      try {
        keysAdded = selector.select(30000);
        System.out.println("  * Selector: out of select(30000)");

        while (!pendingQueue.isEmpty() && handleConnections) {
          SocketChannel channel = (SocketChannel)pendingQueue.remove();
          SelectionKey clientKey = channel.register(selector, SelectionKey.OP_READ);
          Client client = new Client(...);
          clientKey.attach(client);
        }

        if (keysAdded == 0) {
          System.out.println("  * Selector: continue");
          continue;
        }

        Set readyKeys = selector.selectedKeys();
        Iterator i = readyKeys.iterator();

        while (i.hasNext()) {
          try {
            key = (SelectionKey)i.next();
            i.remove();

            if (!key.isValid())
              Log.echoDebug(" * Selector: Key has been validated, but is being processed");

            if (key.isReadable()) {
              Client c = (Client)key.attachment();
              Log.echoDebug("  * Selector: Readable: "+c.getClientID());
              key.interestOps(key.interestOps() & (~SelectionKey.OP_READ));
              ClientWorker worker = (ClientWorker)pool.getWorker();
              worker.process(key);

            } else if (key.isWritable()) {
              Client c = (Client)key.attachment();
              Log.echoDebug("  * Selector: Writable: "+c.getClientID());
              key.interestOps(key.interestOps() & (~SelectionKey.OP_WRITE));
              ClientWorker worker = (ClientWorker)pool.getWorker();
              worker.process(key);

            } else {
              Log.echoDebug(" * Selector: Noticed, but key either readable nor writable");
            }
          } catch (CancelledKeyException cke) {
            Client client = (Client)key.attachment();
            if (client != null)
              client.disconnect(cke.getMessage());
          }
        }
      } catch (CancelledKeyException cke) {
        if (key != null) {
          Client client = (Client)key.attachment();
          if (client != null)
            client.disconnect(cke.getMessage());
        }
      } catch (Exception e) {
        e.printStackTrace();
      }
    }
  } catch (Exception e) {
    e.printStackTrace();
  } finally {
    try {
      selector.close();
    } catch (IOException ioe) {/* Ignore */}
  }
  Log.echoSystem("ClientHandler: stopped");
}

Denne metode Client.disconnct(String reason) anvendes til at disconnecte klienter med.

public void disconnect(String reason) {
  synchronized(closeLock) {
    if (connected) {
      connected = false;
      ...
      try {
        if (key != null) {
          key.cancel();
          if (key.selector().isOpen())
            key.selector().wakeup();
        }
      } catch (Exception e) { e.printStackTrace(); }
      try {
        channel().socket().close();
      } catch (Exception e) { e.printStackTrace(); }
    }
  }
}

Nogen der ved hvordan problemet løses??