mp_resource_sharer_stop.patch: you should add a timeout argument to stop() instead of hardcoding a timeout of 5 seconds. It is maybe safer to block until the thread exits by default (so timeout=None by default).

For the new method: it may be nice to document it. Having to import resource_sharer from multiprocessing.reduction is maybe not the best possible API :-/

+        from multiprocessing.reduction import resource_sharer
+        resource_sharer.stop()

> Also, applicative code could be affected.

What is the effect of the patch? For example, on CTRL+c? I don't know the multiprocessing module nor this "resource sharer" thread.