question: public void register ( SelectableChannel channel , int ops , SelectListener selectEventListener ) throws ClosedChannelException { disable ( ) ; try { { SelectionKey key = channel . register ( sel , ops ) ; supposedIOP . put ( key , ops ) ; map . put ( key , selectEventListener ) ; } } finally { enable ( ) ; } }
target:  Register a selection event handler to a selectable channel. <p>  selectEventListener is invoked by one thread at a time.  The rule of thumb is that the listener must not block. Note! If channel is registered and closed, select event is invoked until the channel is unregistered. 