DatagramChannel.close() keeps port open on Windows

Question

I\'m implementing a Discover process that:

• Open a UDP socket to listen for broadcast response on a given port
• Send some requests (and expect later respons

Answer 1

Some parts of a channel close are deferred to the next select() if the channel is registered with a Selector. It is documented somewhere in the forest of Selector, AbstractSelector, SelectorSpi, SelectableChannel, AbstractSelectableChannel, where I can never find it when I need it. If you're within the select loop and thread when you close the channel, you can make it immediate by calling selectNow().