I think that in a multithreaded environment you can try to hang a particular thread by forcing it into the debugger in order to preserve all stack information inside it, but I don't know if that is feasible in the long run on production systems since it opens a gate to possibly DoSing the machine.

I do this with threads but my system is just a chat bot, so it doesn't really ever turn into a problem.

But yea, conditions weren't designed from the start with distributed systems in mind, so you almost need a runtime that can save a whole thread to disk and recover it later. Back in the day though you could just open a window and ask the user what to do directly.

I think it depends on your OS. IIRC, on Windows, it was fairly easy to destabilize the OS by spawning threads in a loop and starving other processes on the system. I haven't used Windows in a long while though, so I cannot say for sure.