add fast exit with double ctrlc

[Studiedlist]

Implemented one of approaches discussed in #711

[WaffleLapkin]

Sorry it took so long to look at this 💀

I don't think I like the approach here. The main problem is that it only changes anything for dispatch, while leaving dispatch_with_listener as-is.

I think ideally you

• Select something like self.force_shutdown here

  teloxide/crates/teloxide/src/dispatching/dispatcher.rs

  Lines 345 to 353 in c7feb38

  	self.workers
  	.drain()
  	.map(|(_chat_id, worker)| worker.handle)
  	.chain(self.default_worker.take().map(|worker| worker.handle))
  	.collect::<FuturesUnordered<_>>()
  	.for_each(|res| async {
  	res.expect("Failed to wait for a worker.");
  	})
  	.await;

• self.force_shutdown is just tokio::sync::oneshot::Receiver<()>
• the send half is self.force_shutdown_sender, has type Option<oneshot::Sender<()>> and can be retrivied with self.force_shutdown_sender.take()
• in setup_ctrlc_handler_inner

  teloxide/crates/teloxide/src/dispatching/dispatcher.rs

  Lines 480 to 493 in c7feb38

  	loop {
  	tokio::signal::ctrl_c().await.expect("Failed to listen for ^C");
  	match token.shutdown() {
  	Ok(f) => {
  	log::info!("^C received, trying to shutdown the dispatcher...");
  	f.await;
  	log::info!("dispatcher is shutdown...");
  	}
  	Err(_) => {
  	log::info!("^C received, the dispatcher isn't running, ignoring the signal")
  	}
  	}
  	}

  
  you rewrite it to something like this:

  // pseudo-code
  tokio::signal::ctrl_c().await.expect("Failed to listen for ^C");
  let mut count = 1;
  while count <= 3 {
      select! {
          r = token.shutdown() => { match r { /* the same */ }; return },
          _ = ctrl_c()... => { count += 1; continue }
        }
  }
  force_shutdown_sender.send(());