Any good example of Non-blocking UDP read?

[Tash Robinson]

I have been searching and can not seem to find a good example of a
working UDP client that listens, but does not block while waiting for
data arrival.

I am trying to write a client application that needs to listen on
several TCP ports and one UDP port. It will send a start signal over
UDP and then a repeated status message of a fixed length will be
returned from the server. I need to listen to these messages, but I
can't stop the program execution if no message is available yet like
the UdpClient.Receive method does. I have found several example of
async TCP but can not figure out how this would work with UDP.

Does anyone have a working example of a non-blocking UDP client, or
can someone give me some guidance in this area?

Thanks!

 

[Philip Rieck]

Tash,

While this isn't an example, this can be done fairly easily with
Socket.BeginReceiveFrom(). Pass this function a delegate, and that delegate
will be called right away from a separate thread. In this delegate you
should then call EndReceiveFrom(), which will block until data is read --
but remember, this blocking happens on a separate thread, so your main
thread can continue to run.

 

[Michi Henning]

I have been searching and can not seem to find a good example of a
working UDP client that listens, but does not block while waiting for
data arrival.

I am trying to write a client application that needs to listen on
several TCP ports and one UDP port. It will send a start signal over
UDP and then a repeated status message of a fixed length will be
returned from the server. I need to listen to these messages, but I
can't stop the program execution if no message is available yet like
the UdpClient.Receive method does. I have found several example of
async TCP but can not figure out how this would work with UDP.

Does anyone have a working example of a non-blocking UDP client, or
can someone give me some guidance in this area?

Put the socket in non-blocking mode and use Select() to check for
any number of readable file descriptors. That's the standard way
of doing this. (Currently, Select() can't be used to block indefinitely --
see the concurrent thread with subject "Blocking Select() does not work."

Cheers,

Michi.