The SelectorThread.SelectTask inner class is responsible for selecting the incoming data from the connection socket.
If the new connection data are pick up by the selector from the socket then a connection job is pushed into the scheduler queue but the thread that selected the connection data tries also to process the job. If there is a free thread in the pool then the new connection job could be processed by the free thread.
But if the new connection socket is selected from server socked then a new job is pushed into the scheduler queue and it will wait for a free thread. The thread that selected the new socket never processes the job and the thread does not process what it killed.
The first selector 0 is always registered in the server socket to wait for a new connection. It makes the first selector special but the work load should be distributed among all selectors.