1 files changed, 18 insertions, 20 deletions

diff --git a/embassy-time/src/timer.rs b/embassy-time/src/timer.rs
index fe0e93951..763bfdeeb 100644
--- a/embassy-time/src/timer.rs
+++ b/embassy-time/src/timer.rs
@@ -1,6 +1,6 @@
 use core::future::{poll_fn, Future};
 use core::pin::Pin;
-use core::task::{Context, Poll, Waker};
+use core::task::{Context, Poll};
 
 use futures_util::future::{select, Either};
 use futures_util::stream::FusedStream;
@@ -8,7 +8,7 @@ use futures_util::{pin_mut, Stream};
 
 use crate::{Duration, Instant};
 
-/// Error returned by [`with_timeout`] on timeout.
+/// Error returned by [`with_timeout`] and [`with_deadline`] on timeout.
 #[derive(Debug, Clone, PartialEq, Eq)]
 #[cfg_attr(feature = "defmt", derive(defmt::Format))]
 pub struct TimeoutError;
@@ -26,6 +26,19 @@ pub async fn with_timeout<F: Future>(timeout: Duration, fut: F) -> Result<F::Out
     }
 }
 
+/// Runs a given future with a deadline time.
+///
+/// If the future completes before the deadline, its output is returned. Otherwise, on timeout,
+/// work on the future is stopped (`poll` is no longer called), the future is dropped and `Err(TimeoutError)` is returned.
+pub async fn with_deadline<F: Future>(at: Instant, fut: F) -> Result<F::Output, TimeoutError> {
+    let timeout_fut = Timer::at(at);
+    pin_mut!(fut);
+    match select(fut, timeout_fut).await {
+        Either::Left((r, _)) => Ok(r),
+        Either::Right(_) => Err(TimeoutError),
+    }
+}
+
 /// A future that completes at a specified [Instant](struct.Instant.html).
 #[must_use = "futures do nothing unless you `.await` or poll them"]
 pub struct Timer {
@@ -47,9 +60,6 @@ impl Timer {
     ///
     /// Example:
     /// ``` no_run
-    /// # #![feature(type_alias_impl_trait)]
-    /// #
-    /// # fn foo() {}
     /// use embassy_time::{Duration, Timer};
     ///
     /// #[embassy_executor::task]
@@ -119,7 +129,7 @@ impl Future for Timer {
         if self.yielded_once && self.expires_at <= Instant::now() {
             Poll::Ready(())
         } else {
-            schedule_wake(self.expires_at, cx.waker());
+            embassy_time_queue_driver::schedule_wake(self.expires_at.as_ticks(), cx.waker());
             self.yielded_once = true;
             Poll::Pending
         }
@@ -132,8 +142,6 @@ impl Future for Timer {
 ///
 /// For instance, consider the following code fragment.
 /// ``` no_run
-/// # #![feature(type_alias_impl_trait)]
-/// #
 /// use embassy_time::{Duration, Timer};
 /// # fn foo() {}
 ///
@@ -152,8 +160,6 @@ impl Future for Timer {
 /// Example using ticker, which will consistently call `foo` once a second.
 ///
 /// ``` no_run
-/// # #![feature(type_alias_impl_trait)]
-/// #
 /// use embassy_time::{Duration, Ticker};
 /// # fn foo(){}
 ///
@@ -204,7 +210,7 @@ impl Ticker {
                 self.expires_at += dur;
                 Poll::Ready(())
             } else {
-                schedule_wake(self.expires_at, cx.waker());
+                embassy_time_queue_driver::schedule_wake(self.expires_at.as_ticks(), cx.waker());
                 Poll::Pending
             }
         })
@@ -221,7 +227,7 @@ impl Stream for Ticker {
             self.expires_at += dur;
             Poll::Ready(Some(()))
         } else {
-            schedule_wake(self.expires_at, cx.waker());
+            embassy_time_queue_driver::schedule_wake(self.expires_at.as_ticks(), cx.waker());
             Poll::Pending
         }
     }
@@ -233,11 +239,3 @@ impl FusedStream for Ticker {
         false
     }
 }
-
-extern "Rust" {
-    fn _embassy_time_schedule_wake(at: Instant, waker: &Waker);
-}
-
-fn schedule_wake(at: Instant, waker: &Waker) {
-    unsafe { _embassy_time_schedule_wake(at, waker) }
-}