Function timeout_at

pub fn timeout_at<F>(deadline: Instant, future: F) -> Timeout<F> 
where
    F: Future,

Requires 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.

This function returns a future whose return type is Result<T,Elapsed>, where T is the return type of the provided future.

If the provided future completes immediately, then the future returned from this function is guaranteed to complete immediately with an Ok variant no matter the provided deadline.

Cancellation

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.

use tokio::time::{Instant, timeout_at};
use tokio::sync::oneshot;

use std::time::Duration;

let (tx, rx) = oneshot::channel();

// 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");
}