// ignore-windows: Concurrency on Windows is not supported yet. // compile-flags: -Zmiri-disable-weak-memory-emulation -Zmiri-preemption-rate=0 use std::sync::atomic::{AtomicUsize, Ordering}; use std::thread::spawn; #[derive(Copy, Clone)] struct EvilSend(pub T); unsafe impl Send for EvilSend {} unsafe impl Sync for EvilSend {} static SYNC: AtomicUsize = AtomicUsize::new(0); pub fn main() { let mut a = 0u32; let b = &mut a as *mut u32; let c = EvilSend(b); // Note: this is scheduler-dependent // the operations need to occur in // order: // 1. store release : 1 // 2. RMW relaxed : 1 -> 2 // 3. store relaxed : 3 // 4. load acquire : 3 unsafe { let j1 = spawn(move || { *c.0 = 1; SYNC.store(1, Ordering::Release); }); let j2 = spawn(move || { if SYNC.swap(2, Ordering::Relaxed) == 1 { // Blocks the acquire-release sequence SYNC.store(3, Ordering::Relaxed); } }); let j3 = spawn(move || { if SYNC.load(Ordering::Acquire) == 3 { *c.0 //~ ERROR Data race detected between Read on Thread(id = 3) and Write on Thread(id = 1) } else { 0 } }); j1.join().unwrap(); j2.join().unwrap(); j3.join().unwrap(); } }