gRPC Hello World Example

Purpose

This was made to prove to myself that the framework could handle what I needed it for. There were two primary requirements for my needs:

1. A sane, stateful, and race-safe server
2. Ability to retain a reference to the server state after starting the server (to enable long running threads acting on the state)

From this project I found that gRPC is probably the right call for my needs, though it is a bit clunkier than tarpc presently.

Usage

Just run cargo run in the root directory, and it should take care of the rest. Use Ctrl-C to stop it. There isn't much to see other than the transition at T+10 seconds when the greeting switches. I tried to make this code as simple as possible so that it would be legible to relative noobs like me.

Things to note

• It seems to be crucial to grab a clone of the Arc<Mutex> before passing it to the service startup. It's probably due to "us" losing ownership after the call to HelloWorldServer::new_service_def(). Just don't forget to do this, and you can make more clones of it later.
• There is a custom build script, it has project-specific verbiage in there, so that will depend on your setup.
• The nonsense around the .to_owned() on the String is magic to me, I don't know what's going on; I just know that the compiler was angry.
• I used antidote::Mutex throughout because poisonable mutexes are annoying and don't provide additional benefit 99% of the time. If you use the std::sync::Mutex, you'll need to do error handling/unwrapping on each .lock() call.