Adding upstream version 86.0.1.upstream/86.0.1upstream

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

1 files changed, 185 insertions, 0 deletions

diff --git a/third_party/rust/tokio/src/time/timeout.rs b/third_party/rust/tokio/src/time/timeout.rs
new file mode 100644
index 0000000000..401856a881
--- /dev/null
+++ b/third_party/rust/tokio/src/time/timeout.rs
@@ -0,0 +1,185 @@
+//! Allows a future to execute for a maximum amount of time.
+//!
+//! See [`Timeout`] documentation for more details.
+//!
+//! [`Timeout`]: struct@Timeout
+
+use crate::time::{delay_until, Delay, Duration, Instant};
+
+use std::fmt;
+use std::future::Future;
+use std::pin::Pin;
+use std::task::{self, Poll};
+
+/// Require a `Future` to complete before the specified duration has elapsed.
+///
+/// If the future completes before the duration has elapsed, then the completed
+/// value is returned. Otherwise, an error is returned and the future is
+/// canceled.
+///
+/// # Cancelation
+///
+/// Cancelling a timeout is done by dropping the future. No additional cleanup
+/// or other work is required.
+///
+/// The original future may be obtained by calling [`Timeout::into_inner`]. This
+/// consumes the `Timeout`.
+///
+/// # Examples
+///
+/// Create a new `Timeout` set to expire in 10 milliseconds.
+///
+/// ```rust
+/// use tokio::time::timeout;
+/// use tokio::sync::oneshot;
+///
+/// use std::time::Duration;
+///
+/// # async fn dox() {
+/// let (tx, rx) = oneshot::channel();
+/// # tx.send(()).unwrap();
+///
+/// // Wrap the future with a `Timeout` set to expire in 10 milliseconds.
+/// if let Err(_) = timeout(Duration::from_millis(10), rx).await {
+///     println!("did not receive value within 10 ms");
+/// }
+/// # }
+/// ```
+pub fn timeout<T>(duration: Duration, future: T) -> Timeout<T>
+where
+    T: Future,
+{
+    let delay = Delay::new_timeout(Instant::now() + duration, duration);
+    Timeout::new_with_delay(future, delay)
+}
+
+/// Require a `Future` to complete before the specified instant in time.
+///
+/// If the future completes before the instant is reached, then the completed
+/// value is returned. Otherwise, an error is returned.
+///
+/// # Cancelation
+///
+/// Cancelling a timeout is done by dropping the future. No additional cleanup
+/// or other work is required.
+///
+/// The original future may be obtained by calling [`Timeout::into_inner`]. This
+/// consumes the `Timeout`.
+///
+/// # Examples
+///
+/// Create a new `Timeout` set to expire in 10 milliseconds.
+///
+/// ```rust
+/// use tokio::time::{Instant, timeout_at};
+/// use tokio::sync::oneshot;
+///
+/// use std::time::Duration;
+///
+/// # async fn dox() {
+/// let (tx, rx) = oneshot::channel();
+/// # tx.send(()).unwrap();
+///
+/// // Wrap the future with a `Timeout` set to expire 10 milliseconds into the
+/// // future.
+/// if let Err(_) = timeout_at(Instant::now() + Duration::from_millis(10), rx).await {
+///     println!("did not receive value within 10 ms");
+/// }
+/// # }
+/// ```
+pub fn timeout_at<T>(deadline: Instant, future: T) -> Timeout<T>
+where
+    T: Future,
+{
+    let delay = delay_until(deadline);
+
+    Timeout {
+        value: future,
+        delay,
+    }
+}
+
+/// Future returned by [`timeout`](timeout) and [`timeout_at`](timeout_at).
+#[must_use = "futures do nothing unless you `.await` or poll them"]
+#[derive(Debug)]
+pub struct Timeout<T> {
+    value: T,
+    delay: Delay,
+}
+
+/// Error returned by `Timeout`.
+#[derive(Debug, PartialEq)]
+pub struct Elapsed(());
+
+impl Elapsed {
+    // Used on StreamExt::timeout
+    #[allow(unused)]
+    pub(crate) fn new() -> Self {
+        Elapsed(())
+    }
+}
+
+impl<T> Timeout<T> {
+    pub(crate) fn new_with_delay(value: T, delay: Delay) -> Timeout<T> {
+        Timeout { value, delay }
+    }
+
+    /// Gets a reference to the underlying value in this timeout.
+    pub fn get_ref(&self) -> &T {
+        &self.value
+    }
+
+    /// Gets a mutable reference to the underlying value in this timeout.
+    pub fn get_mut(&mut self) -> &mut T {
+        &mut self.value
+    }
+
+    /// Consumes this timeout, returning the underlying value.
+    pub fn into_inner(self) -> T {
+        self.value
+    }
+}
+
+impl<T> Future for Timeout<T>
+where
+    T: Future,
+{
+    type Output = Result<T::Output, Elapsed>;
+
+    fn poll(mut self: Pin<&mut Self>, cx: &mut task::Context<'_>) -> Poll<Self::Output> {
+        // First, try polling the future
+
+        // Safety: we never move `self.value`
+        unsafe {
+            let p = self.as_mut().map_unchecked_mut(|me| &mut me.value);
+            if let Poll::Ready(v) = p.poll(cx) {
+                return Poll::Ready(Ok(v));
+            }
+        }
+
+        // Now check the timer
+        // Safety: X_X!
+        unsafe {
+            match self.map_unchecked_mut(|me| &mut me.delay).poll(cx) {
+                Poll::Ready(()) => Poll::Ready(Err(Elapsed(()))),
+                Poll::Pending => Poll::Pending,
+            }
+        }
+    }
+}
+
+// ===== impl Elapsed =====
+
+impl fmt::Display for Elapsed {
+    fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
+        "deadline has elapsed".fmt(fmt)
+    }
+}
+
+impl std::error::Error for Elapsed {}
+
+impl From<Elapsed> for std::io::Error {
+    fn from(_err: Elapsed) -> std::io::Error {
+        std::io::ErrorKind::TimedOut.into()
+    }
+}