Bounded Channels

Bounded and synchronous channels make send block the current thread:

use std::sync::mpsc;
use std::thread;
use std::time::Duration;
fn main() {
    let (tx, rx) = mpsc::sync_channel(3);
    thread::spawn(move || {
        let thread_id = thread::current().id();
        for i in 1..10 {
            tx.send(format!("Message {i}")).unwrap();
            println!("{thread_id:?}: sent Message {i}");
        }
        println!("{thread_id:?}: done");
    });
    thread::sleep(Duration::from_millis(100));
    for msg in rx.iter() {
        println!("Main: got {msg}");
    }
}