use std::sync::{Arc, Barrier};
use std::thread;

fn main() {
    let barrier = Arc::new(Barrier::new(3));
    let mut handles = vec![];

    for i in 0..3 {
        let barrier = Arc::clone(&barrier);
        handles.push(thread::spawn(move || {
            println!("thread {} before barrier", i);
            barrier.wait();
            println!("thread {} after barrier", i);
        }));
    }

    for h in handles {
        h.join().unwrap();
    }
}