[WhyNotHugo]

Thanks for your reply! Indeed, this should still be more efficient than a pure-python approach.

My main confusion around this is: how do I scale threads? Say I have to CPU cores. Do you run one Granian thread and one python thread? I Granian under-uses CPU, Python can't use the excess. But if I run one Granian thread and two python threads, I risk Python leaving Granian with less CPU than it needs.

In practice it should not be hard to find a balance... but somehow I'm still bothered by the fact that the design has no obvious solution for this.