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//@compile-flags: -Zmiri-disable-weak-memory-emulation -Zmiri-preemption-rate=0 -Zmiri-disable-stacked-borrows
use std::ptr::null_mut;
use std::sync::atomic::{AtomicPtr, Ordering};
use std::thread::{sleep, spawn};
use std::time::Duration;
#[derive(Copy, Clone)]
struct EvilSend<T>(pub T);
unsafe impl<T> Send for EvilSend<T> {}
unsafe impl<T> Sync for EvilSend<T> {}
pub fn main() {
// Shared atomic pointer
let pointer = AtomicPtr::new(null_mut::<usize>());
let ptr = EvilSend(&pointer as *const AtomicPtr<usize>);
// Note: this is scheduler-dependent
// the operations need to occur in
// order, otherwise the allocation is
// not visible to the other-thread to
// detect the race:
// 1. stack-allocate
// 2. atomic_store
// 3. atomic_load
// 4. write-value
// 5. write-value
unsafe {
let j1 = spawn(move || {
let ptr = ptr; // avoid field capturing
// Concurrent allocate the memory.
// Uses relaxed semantics to not generate
// a release sequence.
let pointer = &*ptr.0;
let mut stack_var = 0usize;
pointer.store(&mut stack_var as *mut _, Ordering::Release);
sleep(Duration::from_millis(200));
stack_var = 1usize; //~ ERROR: Data race detected between (1) Write on thread `<unnamed>` and (2) Write on thread `<unnamed>`
// read to silence errors
stack_var
});
let j2 = spawn(move || {
let ptr = ptr; // avoid field capturing
let pointer = &*ptr.0;
*pointer.load(Ordering::Acquire) = 3;
});
j1.join().unwrap();
j2.join().unwrap();
}
}
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