Eric Snow <ericsnowcurren...@gmail.com> added the comment:
> I'm running some long-running (possibly infinite) tasks in the thread pool, > and I cancel them in an `atexit` callback To be clear, by "cancel" you are not talking about Future.cancel(). Rather, your handler causes all running tasks to finish (by sending a special message on the socket corresponding to each running task). Is that right? Some other things I inferred from your atexit handler: * it does not make sure the task associated with the socket finishes (no way of knowing?) * so if a task hangs while trying to stop then the running thread in the ThreadPoolExecutor would block shutdown forever * similarly, if a task is stuck handling a request then it will never receive the special message on the socket, either blocking the send() in your handler or causing ThreadPoolExecutor shutdown/atexit to wait forever * it vaguely implies a 1-to-1 relationship between sockets and *running* tasks * likewise that pending (queued) tasks do not have an associated socket (until started) * so once your handler finishes, any tasks pending in the ThreadPoolExecutor queue will eventually get started but never get stopped by your handler; thus you're back to the deadlock situation Does all that sound right? Most of that is relevant to some possible solutions I have in mind. ---------- nosy: +eric.snow _______________________________________ Python tracker <rep...@bugs.python.org> <https://bugs.python.org/issue41962> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
