Adding upstream version 115.7.0esr.upstream/115.7.0esrupstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 49 insertions, 0 deletions

diff --git a/third_party/rust/futures-task/src/arc_wake.rs b/third_party/rust/futures-task/src/arc_wake.rs
new file mode 100644
index 0000000000..aa6de0fc43
--- /dev/null
+++ b/third_party/rust/futures-task/src/arc_wake.rs
@@ -0,0 +1,49 @@
+use alloc::sync::Arc;
+
+/// A way of waking up a specific task.
+///
+/// By implementing this trait, types that are expected to be wrapped in an `Arc`
+/// can be converted into [`Waker`] objects.
+/// Those Wakers can be used to signal executors that a task it owns
+/// is ready to be `poll`ed again.
+///
+/// Currently, there are two ways to convert `ArcWake` into [`Waker`]:
+///
+/// * [`waker`](super::waker()) converts `Arc<impl ArcWake>` into [`Waker`].
+/// * [`waker_ref`](super::waker_ref()) converts `&Arc<impl ArcWake>` into [`WakerRef`] that
+///   provides access to a [`&Waker`][`Waker`].
+///
+/// [`Waker`]: std::task::Waker
+/// [`WakerRef`]: super::WakerRef
+// Note: Send + Sync required because `Arc<T>` doesn't automatically imply
+// those bounds, but `Waker` implements them.
+pub trait ArcWake: Send + Sync {
+    /// Indicates that the associated task is ready to make progress and should
+    /// be `poll`ed.
+    ///
+    /// This function can be called from an arbitrary thread, including threads which
+    /// did not create the `ArcWake` based [`Waker`].
+    ///
+    /// Executors generally maintain a queue of "ready" tasks; `wake` should place
+    /// the associated task onto this queue.
+    ///
+    /// [`Waker`]: std::task::Waker
+    fn wake(self: Arc<Self>) {
+        Self::wake_by_ref(&self)
+    }
+
+    /// Indicates that the associated task is ready to make progress and should
+    /// be `poll`ed.
+    ///
+    /// This function can be called from an arbitrary thread, including threads which
+    /// did not create the `ArcWake` based [`Waker`].
+    ///
+    /// Executors generally maintain a queue of "ready" tasks; `wake_by_ref` should place
+    /// the associated task onto this queue.
+    ///
+    /// This function is similar to [`wake`](ArcWake::wake), but must not consume the provided data
+    /// pointer.
+    ///
+    /// [`Waker`]: std::task::Waker
+    fn wake_by_ref(arc_self: &Arc<Self>);
+}