1. use std::sync::{Arc, Mutex};
    2. use std::thread;
    3. fn main() {
    4.     let mtx = Arc::new(Mutex::new(""));
    5.     let mtx1 = mtx.clone();
    6.     let mtx2 = mtx.clone();
    7.     let n = 50;
    8.     let th1 = thread::spawn(move || {
    9.         mtx1.lock().unwrap();
    10.         printData(n, "*".to_string());
    11.     });
    12.     let th2 = thread::spawn(move || {
    13.         mtx2.lock().unwrap();
    14.         printData(n, "$".to_string());
    15.     });
    16.     th1.join();
    17.     th2.join();
    18. }