Using multiple threads in Rust. The tests are measured to quantify the impact of concurrency.

threads.rs

use std::thread;
use std::time::Duration;
use std::sync::mpsc;
use std::time::Instant;

fn start(label: &String) -> Instant {
    println!("Start {}", label);
    Instant::now()
}

fn end(now: Instant){
    let elapsed = now.elapsed();
    let sec = (elapsed.as_secs() as f64) + (elapsed.subsec_nanos() as f64 / 1000_000_000.0);
    println!("Took {} seconds", sec);
}


fn test1(label: String, pause_time_millis: u64) {
    let now = start(&label);
    for i in 1..10 {
        thread::sleep(Duration::from_millis(pause_time_millis));
        let result = format!("hello-{}", i);
        println!("Got: {}", result);
    }
    end(now);
}

fn test2(label: String, pause_time_millis: u64) {
    let (tx, rx) = mpsc::channel();
    let now = start(&label);
    for i in 1..10 {
        let tx1 = mpsc::Sender::clone(&tx);
        thread::spawn(move || {
            thread::sleep(Duration::from_millis(pause_time_millis));
            let result = format!("hello-{}", i);
            tx1.send(format!("hello-{}", i)).unwrap();
            result
        });
    }
    drop(tx);
    for received in rx {
        println!("Got: {}", received);
    }
    end(now);
}

fn main() {
    let pause_time_millis = 1000;
    test1(String::from("No async"), pause_time_millis);
    test2(String::from("Aync"), pause_time_millis);
}