use std::cell::Cell;
use tokio::sync::oneshot;

pub fn init () -> oneshot::Receiver <()> {
	let (tx, rx) = oneshot::channel::<()> ();
	
	// I have to put the tx into a Cell here so that if Ctrl-C gets
	// called multiple times, we won't send multiple shutdowns to the
	// oneshot channel. (Which would be a compile error)
	
	let tx = Some (tx);
	let tx = Cell::new (tx);
	
	ctrlc::set_handler (move ||{
		let tx = tx.replace (None);
		
		if let Some (tx) = tx {
			tx.send (()).unwrap ();
		}
	}).expect ("Error setting Ctrl-C handler");
	
	rx
}