LoopCommunicator: RuntimeWarning: coroutine 'create_task.<locals>.run_task' was never awaited

[chrisjsewell]

I've seen this quite a few times now in unit tests, for example in aiidateam/aiida-core#4775 (comment)
This coroutine is created in plumpy.futures.create_task, which is called by plumpy.communicator.convert_to_comm, that is used when adding an rpc/task/broadcast subscriber in plumpy.communicator.LoopCommunicator.

It is weird that it should say it was not awaited, because it is wrapped in asyncio.run_coroutine_threadsafe(run_task(), loop), so you would think that it should always be awaited.

Is this just because the loop is closed while run_task() is running (I guess these tasks should run forever until the subscriber is removed), or does it point to a deeper problem?
Could LoopCommunicator.close ensure such tasks are stopped gracefully, e.g. by ensuring all subscribers are removed.

cc @unkcpz

[unkcpz]

I also curious why this happened and sorry that I have no opinion on how to fix this. 😭 I remember this message first time appeared was after I put the run_task in the thread safe. As for your guess, when and why the loop here is being closed? now the Runner has only one loop in its lifetime.

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On Fri, Feb 26, 2021 at 17:25 Chris Sewell ***@***.***> wrote: I've seen this quite a few times now, for example in aiidateam/aiida-core#4775 (comment) <aiidateam/aiida-core#4775 (comment)> This coroutine is created in plumpy.futures.create_task, which is called by plumpy.communicator.convert_to_comm, that is used when adding an rpc/task/broadcast subscriber in plumpy.communicator.LoopCommunicator. It is weird that it should say it was not awaited, because it is wrapped in asyncio.run_coroutine_threadsafe(run_task(), loop), so you would think that it should always be awaited. Is this just because the loop is closed while run_task() is running (I guess these tasks should run forever until the subscriber is removed), or does it point to a deeper problem? Could LoopCommunicator.close ensure such tasks are stopped gracefully, e.g. by ensuring all subscribers are removed. cc @unkcpz <https://github.com/unkcpz> — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub <#211>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ACDMFRPC2EO2NBJHCXHRU5TTA5SHHANCNFSM4YIDCFKA> .