/**
* Registers a new channel with this Selector. If we've already stored over the limit of channels,
* this will store the channel in a temporary list to be cancelled on the next selection.
*/
@Override
protected synchronized SelectionKey register(AbstractSelectableChannel ch, int ops, Object att) {
int connID;
if (!(ch instanceof UDPSocketChannel)) throw new IllegalSelectorException();
UDPSocketChannel channel = (UDPSocketChannel) ch;
UDPSocketChannel[] copy = new UDPSocketChannel[_channels.length];
for (int i = 0; i < _channels.length; i++) copy[i] = _channels[i];
for (int i = 1; i <= copy.length; i++) {
connID = (_lastConnectionID + i) % 256;
// We don't assign zero.
if (connID == 0) continue;
// If the slot is open, take it.
if (copy[connID] == null) {
_lastConnectionID = connID;
copy[connID] = channel;
channel.getProcessor().setConnectionId((byte) connID);
_channels = copy;
return new UDPSelectionKey(this, att, ch, ops);
}
}
// We don't have enough space for this connection. Add it to a temporary
// list of bad connections which will be removed during selectNow.
LOG.warn("Attempting to add over connection limit");
channelsToRemove.add(ch);
return new UDPSelectionKey(this, att, ch, ops);
}
/** Polls through all available channels and returns those that are ready. */
@Override
public int selectNow() throws IOException {
UDPSocketChannel[] array = _channels;
UDPSocketChannel[] removed = null;
selectedKeys.clear();
for (int i = 0; i < array.length; i++) {
UDPSocketChannel channel = array[i];
if (channel == null) continue;
UDPSelectionKey key = (UDPSelectionKey) channel.keyFor(this);
if (key != null) {
if (key.isValid() && channel.isOpen()) {
int currentOps = channel.getProcessor().readyOps();
int readyOps = currentOps & key.interestOps();
if (readyOps != 0) {
key.setReadyOps(readyOps);
selectedKeys.add(key);
}
} else {
if (removed == null) removed = new UDPSocketChannel[array.length];
removed[i] = channel;
}
}
}
// Go through the removed list & remove them from _connections.
// _connections may have changed (since we didn't lock while polling),
// so we need to check and ensure the given UDPConnectionProcessor
// is the same.
synchronized (this) {
if (removed != null) {
UDPSocketChannel[] copy = new UDPSocketChannel[_channels.length];
for (int i = 0; i < _channels.length; i++) {
if (_channels[i] == removed[i]) copy[i] = null;
else copy[i] = _channels[i];
}
_channels = copy;
}
if (!channelsToRemove.isEmpty()) {
for (SelectableChannel next : channelsToRemove) {
UDPSelectionKey key = (UDPSelectionKey) next.keyFor(this);
key.cancel();
key.setReadyOps(0);
selectedKeys.add(key);
}
channelsToRemove.clear();
}
}
return selectedKeys.size();
}
/** Determines if we're connected to the given host. */
public boolean isConnectedTo(InetAddress host) {
UDPSocketChannel[] array = _channels;
if (_lastConnectionID == 0) return false;
for (int i = 0; i < array.length; i++) {
UDPSocketChannel channel = array[i];
if (channel != null && host.equals(channel.getRemoteSocketAddress().getAddress())) {
return true;
}
}
return false;
}
/**
* Route a message to the {@link UDPConnectionProcessor} identified via the message's connection
* ID. Notifies the provided listener (if any) if the channel is ready to produce events.
*/
public void routeMessage(RUDPMessage msg, InetSocketAddress addr) {
UDPSocketChannel[] array = _channels;
int connID = msg.getConnectionID() & 0xff;
UDPSocketChannel channel = null;
// If connID equals 0 and SynMessage then associate with a connection
// that appears to want it (connecting and with knowledge of it).
if (connID == 0 && msg instanceof SynMessage) {
LOG.debugf("route sym: {0}", msg);
for (int i = 1; i < array.length; i++) {
channel = array[i];
if (channel == null) continue;
LOG.debugf("non-empty index: {0}, addr: {1}", i, channel.getRemoteSocketAddress());
if (channel.isConnectionPending() && channel.isForMe(addr, (SynMessage) msg)) {
LOG.debugf(
"found index: {0}, sender id: {1}", i, ((SynMessage) msg).getSenderConnectionID());
channel.getProcessor().handleMessage(msg);
break;
}
}
// Note: eventually these messages should find a match
// so it is safe to throw away premature ones
} else if (array[connID] != null) { // If valid connID then send on to connection
channel = array[connID];
if (msg instanceof SynMessage) {
LOG.debugf("already assigned syn: {0}", msg);
}
if (channel.getRemoteSocketAddress().equals(addr)) channel.getProcessor().handleMessage(msg);
} else {
LOG.debugf("message for non-existing connection: {0}", msg);
}
if (channel != null && channel.getProcessor().readyOps() != 0)
context.getTransportListener().eventPending();
}
