Beginner async question

[Levi_Roth]

I think this is the same issue that you encountered in a previous thread:

Async socket question

Ah, I believe what is happening is that you have two simultaneous calls to Reader.read, which is disallowed (see the module comment on Reader): Each of the read functions returns a deferred that will become determined when the read completes. It is an error to have two simultaneous reads. That is, if you call a read function, you should not call another read function until the first one completes. One suggestion would be to use the Pipe interface rather than directly using Reader. You can…

I’m not super familiar with async IO stuff, but Pipe.read_choice does sound like it’s designed for use cases just like yours.