Shared via Rust Playground

playground.rs

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

struct Toaster {
    count: u32
}

impl Toaster {
    fn new() -> Toaster {
        Toaster { count: 0 }
    }
}

fn main() {
    let toaster = Arc::new(Mutex::new(Toaster::new()));

    let threads: Vec<_> =
        (0..3)
        .map(|_| {
            let toaster = toaster.clone();
            thread::spawn(move || {
                // load and increment toaster's count, atomically
                let mut t = toaster.lock().unwrap();
                let index = t.count;
                t.count += 1;
                println!("My index is {:?}", index);
            })
        })
        .collect();

    for t in threads {
        t.join().unwrap();
    }
}