use std::collections::VecDeque;
use std::{thread, time};
use std::sync::{Arc, Mutex};

type Que = Arc<Mutex<VecDeque<i64>>>;

fn simulate_input(ev: &mut Que) {
    let interval = time::Duration::from_millis(100);
    for i in 0..10 {
        ev.lock().unwrap().push_back(i);
        thread::sleep(interval);
    }
}

fn simulate_render(ev: &mut Que) {
    loop {
        if let Some(i) = ev.lock().unwrap().pop_front() {
            eprintln!("{}", i);
            if i >= 9 {
                break;
            }
        }
    }
}

fn main() {
    let ev = Arc::new(Mutex::new(VecDeque::new()));

    let start = |f: fn(&mut Que)| {
        let mut ev = ev.clone();
        thread::spawn(move || {
            f(&mut ev);
        })
    };

    let render = start(simulate_render);
    let input = start(simulate_input);

    render.join().unwrap();
    input.join().unwrap();
}