gololang.concurrent.async

Class Promise

java.lang.Object

gololang.concurrent.async.Promise

public final class Promise
extends java.lang.Object

A promise object is used to abstract over possibly asynchronous computations. You should consult the "golodoc" of the gololang.Async module.

See Also:

Future, AssignedFuture

Constructor Summary

Constructors

Constructor and Description
Promise()

Method Summary

Modifier and Type	Method and Description
java.lang.Object	blockingGet() Blocking get, waiting until the promise is resolved.
Promise	fail(java.lang.Throwable throwable) Fails the promise.
Future	future() Creates a new future to observe the eventual resolution of this promise.
java.lang.Object	get() Non-blocking get.
boolean	isFailed() Checks whether the promise has failed.
boolean	isResolved() Checks whether the promise has been resolved.
Promise	set(java.lang.Object value) Sets the promise value.
java.lang.String	toString()

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

Promise

public Promise()

Method Detail

isResolved

public boolean isResolved()

Checks whether the promise has been resolved.

Returns:

true if it has been resolved, false otherwise.

isFailed

public boolean isFailed()

Checks whether the promise has failed.

Returns:

true if it has been resolved and failed, false otherwise.

get

public java.lang.Object get()

Non-blocking get.

Returns:

the promise value, which may be null if it has not been resolved yet.

blockingGet

public java.lang.Object blockingGet()
                             throws java.lang.InterruptedException

Blocking get, waiting until the promise is resolved.

Returns:

the promise value.

Throws:

java.lang.InterruptedException - if the current thread gets interrupted.

set

public Promise set(java.lang.Object value)

Sets the promise value. This has no effect if the promise has already been resolved.

Parameters:

value - the value.

Returns:

this promise.

fail

public Promise fail(java.lang.Throwable throwable)

Fails the promise. This has no effect if the promise has already been resolved.

Parameters:

throwable - the failure.

Returns:

this promise.

future

public Future future()

Creates a new future to observe the eventual resolution of this promise.

Returns:

a new future object.

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object