use std::sync::{Barrier, RwLock};

fn main() {
    for i in 0.. {
        let lock = RwLock::new(());

        let barrier = Barrier::new(5);
        let write_guard = lock.write();

        std::thread::scope(|s| {
            for _ in 0..5 {
                s.spawn(|| {
                    let read_guard = lock.read();
                    barrier.wait();
                    drop(read_guard);
                });
            }

            drop(write_guard);
        });

        println!("{i}");
    }
}