How to shutdown gracefully in tonic? hyper is ok!

[xiuno]

I am using tonic to build a service, I want to shutdown gracefully:
step 1: close all connections with deadline 10 seconds.
step 2: save data to disk.

when I use following code:

Server::builder()
        .add_service(GameServer::new(game))
        .serve_with_shutdown(addr, async {
            println!("waiting ctrl+C...");
            tokio::spawn(tokio::signal::ctrl_c()).await;
            println!("after ctrl+C!");
            // how to disconnect all connections ? ...
            // save data to disk...
            // handler1.abort();
        });

if I press Ctrl+C to abort client first, then press Ctrl+C to abort server, all is ok. but when I press Ctrl+C to abort server first, it will execute to "after Ctrl+C" and continue send data to client, don't close connections and exit.

I tried to test hyper, that's ok. so I don't clear what happened in tonic.
https://play.rust-lang.org/?version=stable&mode=debug&edition=2018&gist=d3a753d783d94132f171c4ae5528ebd0

tonic test code in attachment:
test-tonic.tar.gz