#![allow(dead_code, deprecated, unused_variables, unused_mut)]
use std::sync::atomic::AtomicBool;
use std::sync::atomic::fence;
use std::sync::atomic::Ordering;
pub struct Mutex {
    flag: AtomicBool,
}
impl Mutex {
    pub fn new() -> Mutex {
        Mutex {
            flag: AtomicBool::new(false),
        }
    }
    pub fn lock(&self) {
        while self
            .flag
            .compare_exchange_weak(false, true, Ordering::Relaxed, Ordering::Relaxed)
            .is_err()
        {}
        fence(Ordering::Acquire);
    }
    pub fn unlock(&self) {
        self.flag.store(false, Ordering::Release);
    }
}
fn main() {}