From 092a1ab001c93b98245a9f79cbf004a02f442b1a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Tom=C3=A1s=20Vallotton?= <tvallotton@uc.cl>
Date: Sat, 9 Mar 2024 14:38:58 -0300
Subject: [PATCH] fix: remove memory leak due to missing drop implementation
for local waker. Also, fix some of the stability attributes of LocalWaker's
methods.
---
library/core/src/task/wake.rs | 21 ++++++++++++++++-----
1 file changed, 16 insertions(+), 5 deletions(-)
diff --git a/library/core/src/task/wake.rs b/library/core/src/task/wake.rs
index 8fc942dedc9be..1b43c46bda515 100644
--- a/library/core/src/task/wake.rs
+++ b/library/core/src/task/wake.rs
@@ -622,7 +622,7 @@ impl LocalWaker {
///
/// [`poll()`]: crate::future::Future::poll
#[inline]
- #[stable(feature = "futures_api", since = "1.36.0")]
+ #[unstable(feature = "local_waker", issue = "118959")]
pub fn wake(self) {
// The actual wakeup call is delegated through a virtual function call
// to the implementation which is defined by the executor.
@@ -644,7 +644,7 @@ impl LocalWaker {
/// the case where an owned `Waker` is available. This method should be preferred to
/// calling `waker.clone().wake()`.
#[inline]
- #[stable(feature = "futures_api", since = "1.36.0")]
+ #[unstable(feature = "local_waker", issue = "118959")]
pub fn wake_by_ref(&self) {
// The actual wakeup call is delegated through a virtual function call
// to the implementation which is defined by the executor.
@@ -664,7 +664,7 @@ impl LocalWaker {
/// avoid cloning the waker when they would wake the same task anyway.
#[inline]
#[must_use]
- #[stable(feature = "futures_api", since = "1.36.0")]
+ #[unstable(feature = "local_waker", issue = "118959")]
pub fn will_wake(&self, other: &LocalWaker) -> bool {
self.waker == other.waker
}
@@ -676,7 +676,7 @@ impl LocalWaker {
/// Therefore this method is unsafe.
#[inline]
#[must_use]
- #[stable(feature = "futures_api", since = "1.36.0")]
+ #[unstable(feature = "local_waker", issue = "118959")]
#[rustc_const_unstable(feature = "const_waker", issue = "102012")]
pub const unsafe fn from_raw(waker: RawWaker) -> LocalWaker {
Self { waker }
@@ -748,7 +748,18 @@ impl AsRef<LocalWaker> for Waker {
}
}
-#[stable(feature = "futures_api", since = "1.36.0")]
+#[unstable(feature = "local_waker", issue = "118959")]
+impl Drop for LocalWaker {
+ #[inline]
+ fn drop(&mut self) {
+ // SAFETY: This is safe because `LocalWaker::from_raw` is the only way
+ // to initialize `drop` and `data` requiring the user to acknowledge
+ // that the contract of `RawWaker` is upheld.
+ unsafe { (self.waker.vtable.drop)(self.waker.data) }
+ }
+}
+
+#[unstable(feature = "local_waker", issue = "118959")]
impl fmt::Debug for LocalWaker {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
let vtable_ptr = self.waker.vtable as *const RawWakerVTable;