diff options
Diffstat (limited to 'rtic-channel/src/lib.rs')
| -rw-r--r-- | rtic-channel/src/lib.rs | 15 |
1 files changed, 9 insertions, 6 deletions
diff --git a/rtic-channel/src/lib.rs b/rtic-channel/src/lib.rs index 47e4a77d..a4e49358 100644 --- a/rtic-channel/src/lib.rs +++ b/rtic-channel/src/lib.rs @@ -240,7 +240,8 @@ impl<'a, T, const N: usize> Sender<'a, T, N> { pub async fn send(&mut self, val: T) -> Result<(), NoReceiver<T>> { let mut link_ptr: Option<Link<Waker>> = None; - // Make this future `Drop`-safe, also shadow the original definition so we can't abuse it. + // Make this future `Drop`-safe. + // SAFETY(link_ptr): Shadow the original definition of `link_ptr` so we can't abuse it. let mut link_ptr = LinkPtr(&mut link_ptr as *mut Option<Link<Waker>>); let mut link_ptr2 = link_ptr.clone(); @@ -276,11 +277,13 @@ impl<'a, T, const N: usize> Sender<'a, T, N> { // Place the link in the wait queue on first run. let link_ref = link.insert(Link::new(cx.waker().clone())); - // SAFETY: The address to the link is stable as it is hidden behind - // `link_ptr`, and `link_ptr` shadows the original making it unmovable. - self.0 - .wait_queue - .push(unsafe { Pin::new_unchecked(link_ref) }); + // SAFETY(new_unchecked): The address to the link is stable as it is defined + // outside this stack frame. + // SAFETY(push): `link_ref` lifetime comes from `link_ptr` that is shadowed, + // and we make sure in `dropper` that the link is removed from the queue + // before dropping `link_ptr` AND `dropper` makes sure that the shadowed + // `link_ptr` lives until the end of the stack frame. + unsafe { self.0.wait_queue.push(Pin::new_unchecked(link_ref)) }; return None; } |