PollableFuture<T> class

An implementation of Future that allows synchronously retrieving the value if it has already been completed.

A PollableFuture wraps an existing Future. Unless the PollableFuture is initialized with a non-Future value, it cannot be marked as completed until execution returns to the event loop after the underlying Future has completed. Consequently, a PollableFuture cannot be used to implement a spinlock that synchronously blocks while waiting for a Future to complete.

Implemented types

• Future<T>

Available extensions

• FutureCast
• FutureExtensions
• FutureOfJSAnyToJSPromise
• FutureOfVoidToJSPromise
• PollableFutureExtension

Constructors

PollableFuture(FutureOr<T> futureOrValue)

Constructor.

Properties

hashCode → int

The hash code for this object.

no setter, inherited

isCompleted → bool

Returns true if the PollableFuture has completed, false otherwise.

no setter

runtimeType → Type

A representation of the runtime type of the object.

no setter, inherited

toJS → JSPromise<T>

Available on Future<T>, provided by the FutureOfJSAnyToJSPromise extension

A JSPromise that either resolves with the result of the completed Future or rejects with an object that contains its error.

no setter

toJS → JSPromise<JSAny?>

Available on Future<void>, provided by the FutureOfVoidToJSPromise extension

A JSPromise that either resolves once this Future completes or rejects with an object that contains its error.

no setter

value → T

Returns the completed value.

no setter

Methods

asStream() → Stream<T>

Creates a Stream containing the result of this future.

override

cast<R>() → Future<R>

Available on Future<T>, provided by the FutureCast extension

Casts a Future<T> to a Future<R>.

catchError(Function onError, {bool test(Object)?}) → Future<T>

Handles errors emitted by this Future.

override

ignore() → void

Available on Future<T>, provided by the FutureExtensions extension

Completely ignores this future and its result.

noSuchMethod(Invocation invocation) → dynamic

Invoked when a nonexistent method or property is accessed.

inherited

onError<E extends Object>(FutureOr<T> handleError(E error, StackTrace stackTrace), {bool test(E error)?}) → Future<T>

Available on Future<T>, provided by the FutureExtensions extension

Handles errors on this future.

then<R>(FutureOr<R> onValue(T), {Function? onError}) → Future<R>

Register callbacks to be called when this future completes.

override

timeout(Duration timeLimit, {FutureOr<T> onTimeout()?}) → Future<T>

Stop waiting for this future after timeLimit has passed.

override

toPollable() → PollableFuture<T>

Available on Future<T>, provided by the PollableFutureExtension extension

Wraps this Future with a PollableFuture.

toString() → String

A string representation of this object.

inherited

whenComplete(FutureOr<void> action()) → Future<T>

Registers a function to be called when this future completes.

override

Operators

operator ==(Object other) → bool

The equality operator.

inherited