use std::sync::RwLock;

fn main() {
    // read config into mutex
    let foo = RwLock::new(String::from("asd"));

    let read_lock_a = foo.read().unwrap();
    let read_lock_b = foo.read().unwrap();
    println!("{} {}",read_lock_a,read_lock_b); // two read locks at once
    drop(read_lock_a);
    drop(read_lock_b);

    // change foo
    let mut write_lock = foo.write().unwrap();
    *write_lock = String::from("asd");
    // now store that back to a file if wanted
    drop(write_lock);

    // read again, from memory, we don't re-read anything
    let read_lock = foo.read().unwrap();
    println!("{}",read_lock);
}