// We want to control preemption here. Stacked borrows interferes by having its own accesses. //@compile-flags: -Zmiri-deterministic-concurrency -Zmiri-disable-stacked-borrows use std::sync::atomic::{AtomicUsize, Ordering}; use std::thread::{sleep, spawn}; use std::time::Duration; #[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, the sleep operations currently // force the desired ordering: // 1. store release : 1 // 2. store relaxed : 2 // 3. store relaxed : 3 // 4. load acquire : 3 unsafe { let j1 = spawn(move || { let c = c; // avoid field capturing *c.0 = 1; SYNC.store(1, Ordering::Release); sleep(Duration::from_millis(200)); SYNC.store(3, Ordering::Relaxed); }); let j2 = spawn(move || { // Blocks the acquire-release sequence SYNC.store(2, Ordering::Relaxed); }); let j3 = spawn(move || { let c = c; // avoid field capturing sleep(Duration::from_millis(500)); if SYNC.load(Ordering::Acquire) == 3 { *c.0 //~ ERROR: Data race detected between (1) non-atomic write on thread `unnamed-1` and (2) non-atomic read on thread `unnamed-3` } else { 0 } }); j1.join().unwrap(); j2.join().unwrap(); j3.join().unwrap(); } }