Hi Dave,

You assumption is correct, if UDPClient.Receive will block until data
arrive.

I think you may try to use the Performance Monitor to track the Thread
Object in your application.
Here is the steps I use with the notepad application for demo.(Start
notepad first)
1. run Perfmon
2. Clear all the existing counter
3. Press Ctrl+I to add new counter
4. Select the computer to local computer
5. Select Thread in the Performance Object
6. Select % Processor Time in the Counter List
7. in the right listbox, select the Instance notepad/0(here the notepad is
the process image name and the 0 is the thread number, if your process
running udpclient have multiple threads, select them all)
8. Click Add
9. Now the Chart should be level to 0
10. we activate the notepad window, and we will find that a pulse occur,
the Counter will large than 0.
11. If we input something, the Chart will change.

You may try that steps in your scenario to see what is the result in your
scenario and let me know the result.
Thanks!

Best regards,

Peter Huang

Microsoft Online Community Support
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