Currently all route handlers needs to be Send, Sync and 'static, the default hyper Executor only requires Send and 'static bounds (see this line).
The Sync bound is currently needed because RouterService holds an Arc<Router> which only implements Send if the underlying type is both Send AND Sync.
A workaround would be to wrap the router in a Mutex: Arc<Mutex<Router>>. Since Mutex implements Send and Sync for all types that are Send this should removes the need for all Sync bounds.
However this would prevent the user from wrapping a Router in an Arc themself:
// `router` won't be `Send` because of `Arc` `Sync` requirements
let router = Arc::new(Router::default());
let make_svc = make_service_fn(move |_| {
let router = router.clone();
async move {
Ok::<_, Infallible>(service_fn(move |req: Request<Body>| {
let router = router.clone();
async move { router.serve(req).await }
}))
}
});
let server = Server::bind(&([127, 0, 0, 1], 3000).into())
.serve(make_svc)
.await;An alternative would be to wrap all the inner fields of Router in a struct, wrapped in a Mutex:
struct Router {
inner: Mutex<RouterInner>
}
struct RouterInner {
/* -- snip --*/
}There may be other solutions, but I'm not aware of them ATM.
Currently all route handlers needs to be
Send,Syncand'static, the default hyperExecutoronly requiresSendand'staticbounds (see this line).The
Syncbound is currently needed becauseRouterServiceholds anArc<Router>which only implementsSendif the underlying type is bothSendANDSync.A workaround would be to wrap the router in a
Mutex:Arc<Mutex<Router>>. SinceMuteximplementsSendandSyncfor all types that areSendthis should removes the need for allSyncbounds.However this would prevent the user from wrapping a
Routerin anArcthemself:An alternative would be to wrap all the inner fields of
Routerin a struct, wrapped in aMutex:There may be other solutions, but I'm not aware of them ATM.