1 files changed, 46 insertions, 0 deletions
diff --git a/third_party/rust/tokio/src/io/util/shutdown.rs b/third_party/rust/tokio/src/io/util/shutdown.rs
new file mode 100644
index 0000000000..6d30b004b1
--- /dev/null
+++ b/third_party/rust/tokio/src/io/util/shutdown.rs
@@ -0,0 +1,46 @@
+use crate::io::AsyncWrite;
+
+use pin_project_lite::pin_project;
+use std::future::Future;
+use std::io;
+use std::marker::PhantomPinned;
+use std::pin::Pin;
+use std::task::{Context, Poll};
+
+pin_project! {
+    /// A future used to shutdown an I/O object.
+    ///
+    /// Created by the [`AsyncWriteExt::shutdown`][shutdown] function.
+    /// [shutdown]: crate::io::AsyncWriteExt::shutdown
+    #[must_use = "futures do nothing unless you `.await` or poll them"]
+    #[derive(Debug)]
+    pub struct Shutdown<'a, A: ?Sized> {
+        a: &'a mut A,
+        // Make this future `!Unpin` for compatibility with async trait methods.
+        #[pin]
+        _pin: PhantomPinned,
+    }
+}
+
+/// Creates a future which will shutdown an I/O object.
+pub(super) fn shutdown<A>(a: &mut A) -> Shutdown<'_, A>
+where
+    A: AsyncWrite + Unpin + ?Sized,
+{
+    Shutdown {
+        a,
+        _pin: PhantomPinned,
+    }
+}
+
+impl<A> Future for Shutdown<'_, A>
+where
+    A: AsyncWrite + Unpin + ?Sized,
+{
+    type Output = io::Result<()>;
+
+    fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
+        let me = self.project();
+        Pin::new(me.a).poll_shutdown(cx)
+    }
+}