From 07b26c242b705b044d59af6a858edd36a1cdc3b1 Mon Sep 17 00:00:00 2001
From: hzlinyiyu <linyiyu1992@gmail.com>
Date: Tue, 1 Nov 2022 19:40:19 +0800
Subject: [PATCH] sync: make Notify panic safe

---
 tokio/src/sync/notify.rs  | 4 ++++
 tokio/tests/unwindsafe.rs | 5 +++++
 2 files changed, 9 insertions(+)

diff --git a/tokio/src/sync/notify.rs b/tokio/src/sync/notify.rs
index 83bd6823694..efe16f9f8ef 100644
--- a/tokio/src/sync/notify.rs
+++ b/tokio/src/sync/notify.rs
@@ -13,6 +13,7 @@ use crate::util::WakeList;
 use std::cell::UnsafeCell;
 use std::future::Future;
 use std::marker::PhantomPinned;
+use std::panic::{RefUnwindSafe, UnwindSafe};
 use std::pin::Pin;
 use std::ptr::NonNull;
 use std::sync::atomic::Ordering::SeqCst;
@@ -566,6 +567,9 @@ impl Default for Notify {
     }
 }
 
+impl UnwindSafe for Notify {}
+impl RefUnwindSafe for Notify {}
+
 fn notify_locked(waiters: &mut WaitList, state: &AtomicUsize, curr: usize) -> Option<Waker> {
     loop {
         match get_state(curr) {
diff --git a/tokio/tests/unwindsafe.rs b/tokio/tests/unwindsafe.rs
index 98cf5b1b044..3e63820864d 100644
--- a/tokio/tests/unwindsafe.rs
+++ b/tokio/tests/unwindsafe.rs
@@ -3,6 +3,11 @@
 
 use std::panic::{RefUnwindSafe, UnwindSafe};
 
+#[test]
+fn notify_is_unwind_safe() {
+    is_unwind_safe::<tokio::sync::Notify>();
+}
+
 #[test]
 fn join_handle_is_unwind_safe() {
     is_unwind_safe::<tokio::task::JoinHandle<()>>();