`autoreload` example can render the shutdown future useless

[cezarmathe]

Bug Report

Version

• tonic v0.5.2
• tonic-build v0.5.2

Platform

Linux 5.14.9-arch2-1

Description

The autoreload example does not set the standard library TCP listener to nonblocking mode. As a result, the shutdown future does not actually shut down the server if it has already received a request.

I made a repository with clear instructions to see this in action: https://github.com/cezarmathe/tonic-listenfd-graceful-shutdown.

I propose either a new example for using tonic with externally managed file descriptors or fixing the autoreload example. I would be happy to help with both.

[LucioFranco]

I would totally accept a PR for this :)