[Feature Request]Something similar to tokio::runtime::Builder::on_thread_start() for actix-web workers

[SteveLauC]

Hi, thanks for this amazing project!

I would like to know do we have something similar to tokio::runtime::Builder::on_thread_start() for workers, so that one can do something when those workers start, e.g., set CPU affinity.

[SteveLauC]

I implemented this in my fork, though I still hope we can have this in the official release:>

[robjtede]

I added an example of how to achieve CPU core pinning.

I'd prefer not to add an on_thread_start method to HttpServer since the app factory functions are run per-worker already.