serve_connection_with_upgrades does not enforce its timeout from initial connection, but initial data.

[randomairborne]

Sysinfo: Hyper 1.4.1 on Darwin 23.6.0 root:xnu-10063.141.2~1/RELEASE_ARM64_T6020 arm64

While l was looking into tokio-rs/axum#2741

I tried this code:

use hyper::{body::Incoming, Request, Response};
use hyper_util::rt::{TokioExecutor, TokioIo, TokioTimer};
use std::convert::Infallible;
use std::time::Duration;
use tokio::net::TcpListener;

#[tokio::main]
async fn main() {
    let listener = TcpListener::bind("0.0.0.0:3000").await.unwrap();
    loop {
        let (socket, _remote_addr) = listener.accept().await.unwrap();
        tokio::spawn(async move {
            let socket = TokioIo::new(socket);
            let hyper_service =
                hyper::service::service_fn(move |_request: Request<Incoming>| async {
                    let t: Result<_, Infallible> = Ok(Response::new("test".to_string()));
                    t
                });

            let mut server = hyper_util::server::conn::auto::Builder::new(TokioExecutor::new());

            server
                .http1()
                .timer(TokioTimer::new())
                .header_read_timeout(Duration::from_secs(1));

            if let Err(err) = server.serve_connection_with_upgrades(socket, hyper_service).await {
                eprintln!("failed to serve connection: {err:#}");
            }
        });
    }
}

I expected a TCP connection opened to the server terminated after not sending data within one second, however, the connection was persisted indefinitely, and only terminated after some amount of data was sent. However, if instead of serve_connection_with_upgrades, serve_connection is used, and http1_only() is also set, Hyper exhibits the correct behavior