1 files changed, 98 insertions, 0 deletions
diff --git a/third_party/rust/tokio-timer/src/delay.rs b/third_party/rust/tokio-timer/src/delay.rs
new file mode 100644
index 0000000000..c48adccd57
--- /dev/null
+++ b/third_party/rust/tokio-timer/src/delay.rs
@@ -0,0 +1,98 @@
+use timer::{HandlePriv, Registration};
+use Error;
+
+use futures::{Future, Poll};
+
+use std::time::{Duration, Instant};
+
+/// A future that completes at a specified instant in time.
+///
+/// Instances of `Delay` perform no work and complete with `()` once the
+/// specified deadline has been reached.
+///
+/// `Delay` has a resolution of one millisecond and should not be used for tasks
+/// that require high-resolution timers.
+///
+/// # Cancellation
+///
+/// Canceling a `Delay` is done by dropping the value. No additional cleanup or
+/// other work is required.
+///
+/// [`new`]: #method.new
+#[derive(Debug)]
+pub struct Delay {
+    /// The link between the `Delay` instance at the timer that drives it.
+    ///
+    /// This also stores the `deadline` value.
+    registration: Registration,
+}
+
+impl Delay {
+    /// Create a new `Delay` instance that elapses at `deadline`.
+    ///
+    /// Only millisecond level resolution is guaranteed. There is no guarantee
+    /// as to how the sub-millisecond portion of `deadline` will be handled.
+    /// `Delay` should not be used for high-resolution timer use cases.
+    pub fn new(deadline: Instant) -> Delay {
+        let registration = Registration::new(deadline, Duration::from_millis(0));
+
+        Delay { registration }
+    }
+
+    pub(crate) fn new_timeout(deadline: Instant, duration: Duration) -> Delay {
+        let registration = Registration::new(deadline, duration);
+        Delay { registration }
+    }
+
+    pub(crate) fn new_with_handle(deadline: Instant, handle: HandlePriv) -> Delay {
+        let mut registration = Registration::new(deadline, Duration::from_millis(0));
+        registration.register_with(handle);
+
+        Delay { registration }
+    }
+
+    /// Returns the instant at which the future will complete.
+    pub fn deadline(&self) -> Instant {
+        self.registration.deadline()
+    }
+
+    /// Returns true if the `Delay` has elapsed
+    ///
+    /// A `Delay` is elapsed when the requested duration has elapsed.
+    pub fn is_elapsed(&self) -> bool {
+        self.registration.is_elapsed()
+    }
+
+    /// Reset the `Delay` instance to a new deadline.
+    ///
+    /// Calling this function allows changing the instant at which the `Delay`
+    /// future completes without having to create new associated state.
+    ///
+    /// This function can be called both before and after the future has
+    /// completed.
+    pub fn reset(&mut self, deadline: Instant) {
+        self.registration.reset(deadline);
+    }
+
+    pub(crate) fn reset_timeout(&mut self) {
+        self.registration.reset_timeout();
+    }
+
+    /// Register the delay with the timer instance for the current execution
+    /// context.
+    fn register(&mut self) {
+        self.registration.register();
+    }
+}
+
+impl Future for Delay {
+    type Item = ();
+    type Error = Error;
+
+    fn poll(&mut self) -> Poll<Self::Item, Self::Error> {
+        // Ensure the `Delay` instance is associated with a timer.
+        self.register();
+
+        self.registration.poll_elapsed()
+    }
+}