Struct Delay

pub struct Delay { /* private fields */ }

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.

Implementations

impl Delay

pub fn new(deadline: Instant) -> 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 deadline(&self) -> Instant

Returns the instant at which the future will complete.

pub fn is_elapsed(&self) -> bool

Returns true if the Delay has elapsed

A Delay is elapsed when the requested duration has elapsed.

pub fn reset(&mut self, deadline: Instant)

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.

Trait Implementations

impl Debug for Delay

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Future for Delay

type Item = ()

The type of value that this future will resolved with if it is successful.

type Error = Error

The type of error that this future will resolve with if it fails in a normal fashion.

fn poll(&mut self) -> Poll<Self::Item, Self::Error>

Query this future to see if its value has become available, registering interest if it is not.

fn wait(self) -> Result<Self::Item, Self::Error>

where Self: Sized,

Block the current thread until this future is resolved.

fn map<F, U>(self, f: F) -> Map<Self, F>

where F: FnOnce(Self::Item) -> U, Self: Sized,

Map this future’s result to a different type, returning a new future of the resulting type.

fn map_err<F, E>(self, f: F) -> MapErr<Self, F>

where F: FnOnce(Self::Error) -> E, Self: Sized,

Map this future’s error to a different error, returning a new future.

fn from_err<E>(self) -> FromErr<Self, E>

where E: From<Self::Error>, Self: Sized,

Map this future’s error to any error implementing From for this future’s Error, returning a new future.

fn then<F, B>(self, f: F) -> Then<Self, B, F>

where F: FnOnce(Result<Self::Item, Self::Error>) -> B, B: IntoFuture, Self: Sized,

Chain on a computation for when a future finished, passing the result of the future to the provided closure f.

fn and_then<F, B>(self, f: F) -> AndThen<Self, B, F>

where F: FnOnce(Self::Item) -> B, B: IntoFuture<Error = Self::Error>, Self: Sized,

Execute another future after this one has resolved successfully.

fn or_else<F, B>(self, f: F) -> OrElse<Self, B, F>

where F: FnOnce(Self::Error) -> B, B: IntoFuture<Item = Self::Item>, Self: Sized,

Execute another future if this one resolves with an error.

fn select<B>(self, other: B) -> Select<Self, <B as IntoFuture>::Future>

where B: IntoFuture<Item = Self::Item, Error = Self::Error>, Self: Sized,

Waits for either one of two futures to complete.

fn select2<B>(self, other: B) -> Select2<Self, <B as IntoFuture>::Future>

where B: IntoFuture, Self: Sized,

Waits for either one of two differently-typed futures to complete.

fn join<B>(self, other: B) -> Join<Self, <B as IntoFuture>::Future>

where B: IntoFuture<Error = Self::Error>, Self: Sized,

Joins the result of two futures, waiting for them both to complete.

fn join3<B, C>( self, b: B, c: C, ) -> Join3<Self, <B as IntoFuture>::Future, <C as IntoFuture>::Future>

where B: IntoFuture<Error = Self::Error>, C: IntoFuture<Error = Self::Error>, Self: Sized,

Same as join, but with more futures.

fn join4<B, C, D>( self, b: B, c: C, d: D, ) -> Join4<Self, <B as IntoFuture>::Future, <C as IntoFuture>::Future, <D as IntoFuture>::Future>

where B: IntoFuture<Error = Self::Error>, C: IntoFuture<Error = Self::Error>, D: IntoFuture<Error = Self::Error>, Self: Sized,

Same as join, but with more futures.

fn join5<B, C, D, E>( self, b: B, c: C, d: D, e: E, ) -> Join5<Self, <B as IntoFuture>::Future, <C as IntoFuture>::Future, <D as IntoFuture>::Future, <E as IntoFuture>::Future>

where B: IntoFuture<Error = Self::Error>, C: IntoFuture<Error = Self::Error>, D: IntoFuture<Error = Self::Error>, E: IntoFuture<Error = Self::Error>, Self: Sized,

Same as join, but with more futures.

fn into_stream(self) -> IntoStream<Self>

where Self: Sized,

Convert this future into a single element stream.

fn flatten(self) -> Flatten<Self>

where Self::Item: IntoFuture, <Self::Item as IntoFuture>::Error: From<Self::Error>, Self: Sized,

Flatten the execution of this future when the successful result of this future is itself another future.

fn flatten_stream(self) -> FlattenStream<Self>

where Self::Item: Stream<Error = Self::Error>, Self: Sized,

Flatten the execution of this future when the successful result of this future is a stream.

fn fuse(self) -> Fuse<Self>

where Self: Sized,

Fuse a future such that poll will never again be called once it has completed.

fn inspect<F>(self, f: F) -> Inspect<Self, F>

where F: FnOnce(&Self::Item), Self: Sized,

Do something with the item of a future, passing it on.

fn catch_unwind(self) -> CatchUnwind<Self>

where Self: Sized + UnwindSafe,

Catches unwinding panics while polling the future.

fn shared(self) -> Shared<Self>

where Self: Sized,

Create a cloneable handle to this future where all handles will resolve to the same result.