Does __del__ ever actually get called?

[EternityForest]

It seems like the socket thread holding a reference to the callback prevents del from being called, which means the thread never stops unless you manually call terminate() explicitly, and you get a thread leak.

And when you do call it explicitly, it sometimes stops with a nuisance error when the thread tries to read the closed socket. I work around that by changing the "while True" to "while self.should_run" and setting that to False to stop the loop before shutting down the socket and process.