Snippets

barrier.rs

use std::sync::Arc;
use tokio::sync::{Barrier, Notify};
use tokio::time::{sleep, Duration};

#[tokio::main]
async fn main() {
    let barrier = Arc::new(Barrier::new(10));
    let all_ready_notify = Arc::new(Notify::new());
    let notify_receiver = all_ready_notify.clone();
    for i in 0..10 {
        tokio::spawn(communicate(
            i as f64,
            barrier.clone(),
            all_ready_notify.clone(),
        ));
    }
    notify_receiver.notified().await;
    println!("proceed");
}

async fn communicate(i: f64, barrier: Arc<Barrier>, all_ready_notify: Arc<Notify>) {
    let wait = i / 10.;
    println!("random connections costing {} seconds", wait);
    sleep(Duration::from_secs_f64(wait)).await;

    let wait_result = barrier.wait().await;
    if wait_result.is_leader() {
        all_ready_notify.notify_one();
    }
}