/** 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();
}
