Function with_timeout_state 

pub fn with_timeout_state<S, F>(
    duration: Duration,
    handler: F,
) -> impl Fn(&Request, &PathParams, &ConnectionInfo, &S) -> Response + Send + Sync + 'static
where
    S: Clone + Send + Sync + 'static,
    F: Fn(&Request, &PathParams, &ConnectionInfo, &S) -> Response + Send + Sync + 'static,

Wraps an AppWithState<S> handler (which additionally receives &S) so it must complete within duration or the caller gets 504 Gateway Timeout instead of waiting further.

Requires S: Clone — the wrapped call runs on a background thread that needs its own owned copy of the state, since the handler signature only gives a borrowed &S. Most AppWithState state types hold their own data behind Arc internally and are cheap to #[derive(Clone)]; if yours isn’t, wrap the whole app with TimeoutLayer instead, or switch the route to AsyncAppWithState and use with_timeout_async, which needs no Clone bound at all.