On Wed, Mar 11, 2020 at 3:20 AM Kyle Stanley <aeros...@gmail.com> wrote:
> IIUC, I don't think there's a way that we could reasonably support > stability for provide any guarantees for spawning or interacting with the > Executors from a daemon thread. It might even be worth considering to > explicitly warn or prevent that in some capacity. > We could however easily detect this case: we just need to check current_thread().daemon at submit against existing worker threads. > Antoine Pitrou wrote: > > Daemon threads are already a bad idea, actually. It is really worth > > the effort to ensure your threads exit cleanly rather than expect the > > interpreter to kill them at shutdown. > > Agreed. Furthermore, if there's a thread in a program that can potentially > hang indefinitely, converting them into daemon threads (allowing it to be > killed on interpreter shutdown) just obscures the problem in most cases, > IMO. There should be some consideration placed into preventing a thread > from hanging indefinitely in the first place, such as with timeouts or some > form of outside signaling (such as threading.Event). > > That's not to say that daemon threads aren't sometimes useful. > Essentially, if you're okay with the thread being abruptly killed without > allowing it's resources to be cleaned up gracefully, making it a daemon > thread shouldn't be a significant issue. But, the core problem here is that > ThreadPoolExecutor is an example of a resource that should be cleaned up > gracefully, so spawning it in a daemon thread or trying to interact with it > through one can interfere with that process. > I completely agree (even more so that i already ran into some undying daemon threads): This should be set up from the very start. Sadly, It is very hard to get rid of them when an entire existing codebase rely on those for exit :/ . Anyway, thanks for the information and advices !
_______________________________________________ Python-ideas mailing list -- python-ideas@python.org To unsubscribe send an email to python-ideas-le...@python.org https://mail.python.org/mailman3/lists/python-ideas.python.org/ Message archived at https://mail.python.org/archives/list/python-ideas@python.org/message/PASIDOQLHDGLSCA73UM3KK2T7C534KDR/ Code of Conduct: http://python.org/psf/codeofconduct/
