How to use atomics in Rust

Use std::sync::atomic types like AtomicUsize to perform lock-free, thread-safe operations on shared data. Wrap your value in an atomic type and call methods like .fetch_add() to modify it safely across threads without explicit mutexes.

use std::sync::atomic::{AtomicUsize, Ordering};
use std::sync::Arc;
use std::thread;

let counter = Arc::new(AtomicUsize::new(0));
let mut handles = vec![];

for _ in 0..10 {
    let c = Arc::clone(&counter);
    let handle = thread::spawn(move || {
        c.fetch_add(1, Ordering::SeqCst);
    });
    handles.push(handle);
}

for h in handles { h.join().unwrap(); }
println!("Result: {}", counter.load(Ordering::SeqCst));

Atomics are special variables that multiple threads can update at the same time without crashing your program. Think of them like a shared counter at a store where the cashier updates the total instantly without needing to ask for permission from other cashiers. You use them when you need high-performance counting or flagging across threads without the overhead of locks.