Unsound Issue in SpinLock #1
Description
Hi, thanks for your time to read this issue.
Our static analyzer find a potential unsound issue (data races) in SpinLock, where the unlock fuction needs to be marked as unsafe explicitly, otherwise safe Rust can have data races when user unlock unexpectedly.
Lines 94 to 97 in 6bba839
A potentail PoC code is like:
#[deny(unsafe_code)]
use std::sync::Arc;
use std::thread;
use std::time::Duration;
use anode::spinlock::SpinLock;
fn main() {
let mut s1 = Arc::new(SpinLock::new(5));
let mut s2 = s1.clone();
let h = std::thread::spawn(move || {
let mut guard = s2.lock();
thread::sleep(Duration::from_secs(1));
*guard = 10;
thread::sleep(Duration::from_secs(1));
});
thread::sleep(Duration::from_secs(1));
s1.unlock();
let guard = s1.lock();
let origin = *guard;
for _ in 0..1000000{
if *guard != origin {
println!("{} {}", *guard, origin);
break;
}
}
h.join().unwrap();
}
// output:
// 10 5Thanks again for your time.