Hi! Sorry for the delay, I didn't realize I needed to be subscribed to the mailing list to participate in conversations.
My use case is that I have a gui application which runs arbitrary tasks as background threads, and needs to provide a cancel button to interrupt them. The tasks are often legacy code and/or are very difficult to find reasonable points to insert checks for interruption.
Another use case would be implementing a python shell in a gui. If you want to maintain responsiveness while commands execute, they must be able to run in another thread (or another process, but this is not ideal if the shell is supposed to interact with the internals of your application). Interrupting lines with ctrl-c requires being able to send an exception to worker threads.
Hope this helps!
Thanks, - Audrey