Try It Yourself - SyntaxStudy Editor

HTML / CSS / JS

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

fn main() {
    // --- Arc<Mutex<T>> shared counter ---
    let counter = Arc::new(Mutex::new(0u64));
    let mut handles = vec![];

for _ in 0..8 {
        let c = Arc::clone(&counter);
        handles.push(thread::spawn(move || {
            let mut guard = c.lock().unwrap();  // blocks until lock acquired
            *guard += 1;
        }));                                     // guard dropped → lock released
    }

for h in handles { h.join().unwrap(); }
    println!("counter = {}", *counter.lock().unwrap());

// --- Arc<Mutex<Vec<T>>> shared collection ---
    let log: Arc<Mutex<Vec<String>>> = Arc::new(Mutex::new(Vec::new()));
    let mut handles = vec![];

for i in 0..4 {
        let log = Arc::clone(&log);
        handles.push(thread::spawn(move || {
            let msg = format!("thread {i} reporting");
            log.lock().unwrap().push(msg);
        }));
    }
    for h in handles { h.join().unwrap(); }
    println!("log entries: {:?}", *log.lock().unwrap());

// --- RwLock: many readers, one writer ---
    let data = Arc::new(RwLock::new(vec![1, 2, 3]));
    let r1 = Arc::clone(&data);
    let r2 = Arc::clone(&data);

data.write().unwrap().push(4);
    println!("after write: {:?}", *data.read().unwrap());
}