Lee M

Pretty much done. Apple's implementation doesn't have the shadowy separator though. 

:+1:

Awesome to see this 👍 Is this landing anytime soon?

I'm only using macOS, and don't have a Linux environment to test on :/ It looks like the quiescing implementation in general is incomplete for Vapor, but a good start...

I'll also add that I'm seeing this for post requests with large bodies. As in the file upload will continue successfully after a shutdown has been requested and quiescing events...

This looks great, but I think I'd rather have support built right in as is in other parts of Vapor.

The server isn't behaving as if the port is closed. Packets still seem to be hitting the server, but instead of reaching Vapor and delivering a response, you just get...

Apologies, I think I've misdiagnosed this issue. We *were* genuinely seeing this exact behaviour a year ago, and saw a PR on `swift-nio` that seemed to somewhat reference the symptoms...

Actually, I looked a bit further into this, and you're still forced to incur a 5 second penalty between closing the channel and `onClose` being triggered. This is a shutdown...

On further thought, since it might difficult to provide a reliable `onClosing` that covers all possible closing scenarios, perhaps we should just deliver a `onPingTimeout` that covers just this specific...