tokio mpsc Channel

use tokio::sync::mpsc;

#[tokio::main]
async fn main() {
    let (tx, mut rx) = mpsc::channel::<String>(8);    // capacity 8

    // Spawn 3 producers
    for i in 0..3 {
        let tx = tx.clone();
        tokio::spawn(async move {
            for j in 0..4 {
                tx.send(format!("p{i}-msg{j}")).await.unwrap();
            }
        });
    }
    drop(tx);                              // drop the original — when all clones drop, rx closes

    // Single consumer drains until the channel closes
    while let Some(msg) = rx.recv().await {
        println!("got: {msg}");
    }
    println!("channel closed");
}