On 27 Mar 2013, at 08:11, Holger Hans Peter Freyther <holger@freyther.de> wrote:
On Tue, Mar 26, 2013 at 09:08:09PM +0100, Sven Van Caekenberghe wrote:
Maybe I am telling you things you already know, but TCP and UDP are fundamentally different. UDP is really one-shot, try-and-hope, completely asynchronous. In networking you generally only get a ConnectionClosed when you actually read or write (and even then ;-).
Yes, but at least for the unix platform on close the aio/select handler is removing the socket from the registration. So there is no way to read the zero from the dead socket. :)
For your concrete question (2): just start a reading process, wrap it in a handler and clean up. For UDP this will never happen: you will keep on reading nothing. For TCP reading will eventually fail if the other end disappears.
Do you have an example for "handler and clean up"? I resorted to code like this for now in my 'blocking' read.
[self dataAvailable] whileFalse: [[self waitForDataFor: 10] on: ConnectionTimedOut do: []].
But I have not ported my client code so I don't know if the above is working or not. This way I will get the ConnectionClosed exception at least within 10 seconds.
thank you
holger
It is still not clear to me if this is for UDP or TCP, I would be surprised of #dataAvailable or #waitForData: actually work for UDP. I gave you some pointers to examples that do work. Your code snippet looks reasonable to me, but I would set timeouts on the socket(streams) and use regular read/write operations and then loop. Sven