use std::sync::Mutex;

fn main() {
    let mutex_a = Mutex::new(());
    let mutex_b = Mutex::new(());

    let waiting_time = 1000;

    crossbeam::scope(|s| {
        s.spawn(|_| {
            let b = mutex_b.lock().unwrap();
            std::thread::sleep(std::time::Duration::from_millis(waiting_time));
            let a = mutex_a.lock().unwrap();
        });
        s.spawn(|_| {
            let a = mutex_a.lock().unwrap();
            std::thread::sleep(std::time::Duration::from_millis(waiting_time));
            let b = mutex_b.lock().unwrap();
        });
        std::thread::sleep(std::time::Duration::from_millis(waiting_time));
        let a = mutex_a.lock().unwrap();
        let b = mutex_b.lock().unwrap();
    }).unwrap();
}