/
notify.rs
47 lines (37 loc) · 1.39 KB
/
notify.rs
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use crate::sync::Notify;
use std::future::Future;
use std::mem::ManuallyDrop;
use std::sync::Arc;
use std::task::{Context, RawWaker, RawWakerVTable, Waker};
#[cfg(target_arch = "wasm32")]
use wasm_bindgen_test::wasm_bindgen_test as test;
#[test]
fn notify_clones_waker_before_lock() {
const VTABLE: &RawWakerVTable = &RawWakerVTable::new(clone_w, wake, wake_by_ref, drop_w);
unsafe fn clone_w(data: *const ()) -> RawWaker {
let arc = ManuallyDrop::new(Arc::<Notify>::from_raw(data as *const Notify));
// Or some other arbitrary code that shouldn't be executed while the
// Notify wait list is locked.
arc.notify_one();
let _arc_clone: ManuallyDrop<_> = arc.clone();
RawWaker::new(data, VTABLE)
}
unsafe fn drop_w(data: *const ()) {
let _ = Arc::<Notify>::from_raw(data as *const Notify);
}
unsafe fn wake(_data: *const ()) {
unreachable!()
}
unsafe fn wake_by_ref(_data: *const ()) {
unreachable!()
}
let notify = Arc::new(Notify::new());
let notify2 = notify.clone();
let waker =
unsafe { Waker::from_raw(RawWaker::new(Arc::into_raw(notify2) as *const _, VTABLE)) };
let mut cx = Context::from_waker(&waker);
let future = notify.notified();
pin!(future);
// The result doesn't matter, we're just testing that we don't deadlock.
let _ = future.poll(&mut cx);
}