Thread unloading

[KirillMysnik]

Currently any threads started by the plugin are left running when the plugin unloads.

While it's generally incorrect to kill the threads from outside, maybe we should at least warn about such threads?

E.g.

from threading import Thread
from warnings import warn

from core import WeakAutoUnload


class GameThread(WeakAutoUnload, Thread):
    def _add_instance(self, caller):
        super()._add_instance(caller)
        self._caller = caller

    def _unload_instance(self):
        if self.is_alive():
            warn(
                f"Thread '{self.name}' ({self.ident}) from '{self._caller}' "
                f"is running even though its plugin has been unloaded!")

This will report all threads running at the time of plugin unloading even if the plugin implements some mechanism to stop its threads.

To give a thread some time to realize that the plugin is unloaded, that check can be wrapped and delayed with Delay.

[Ayuto]

I like the idea. Though, I wouldn't delay that check. Plugins that utilize threads should join them in unload.

[KirillMysnik]

Plugins that utilize threads should join them in ''unload''.

Sounds fair to me. Didn't even think of this, that's a nice approach.