Package io.netty.util.concurrent

Class DefaultPromise<V>

java.lang.Object

io.netty.util.concurrent.AbstractFuture<V>

io.netty.util.concurrent.DefaultPromise<V>

All Implemented Interfaces:

Future<V>, Promise<V>, Future<V>

Direct Known Subclasses:

DefaultProgressivePromise

public class DefaultPromise<V>
extends AbstractFuture<V>
implements Promise<V>

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	DefaultPromise()	See executor() for expectations of the executor.
	DefaultPromise(EventExecutor executor)	Creates a new instance.

Method Summary

Modifier and Type	Method	Description
Promise<V>	addListener(GenericFutureListener<? extends Future<? super V>> listener)	Adds the specified listener to this future.
Promise<V>	addListeners(GenericFutureListener<? extends Future<? super V>>... listeners)	Adds the specified listeners to this future.
Promise<V>	await()	Waits for this future to be completed.
boolean	await(long timeoutMillis)	Waits for this future to be completed within the specified time limit.
boolean	await(long timeout, TimeUnit unit)	Waits for this future to be completed within the specified time limit.
Promise<V>	awaitUninterruptibly()	Waits for this future to be completed without interruption.
boolean	awaitUninterruptibly(long timeoutMillis)	Waits for this future to be completed within the specified time limit without interruption.
boolean	awaitUninterruptibly(long timeout, TimeUnit unit)	Waits for this future to be completed within the specified time limit without interruption.
boolean	cancel(boolean mayInterruptIfRunning)	If the cancellation was successful it will fail the future with a CancellationException.
Throwable	cause()	Returns the cause of the failed I/O operation if the I/O operation has failed.
protected void	checkDeadLock()
protected EventExecutor	executor()	Get the executor used to notify listeners when this promise is complete.
V	get()
V	get(long timeout, TimeUnit unit)
V	getNow()	Return the result without blocking.
boolean	isCancellable()	returns true if and only if the operation can be cancelled via Future.cancel(boolean).
boolean	isCancelled()
boolean	isDone()
boolean	isSuccess()	Returns true if and only if the I/O operation was completed successfully.
protected static void	notifyListener(EventExecutor eventExecutor, Future<?> future, GenericFutureListener<?> listener)	Notify a listener that a future has completed.
Promise<V>	removeListener(GenericFutureListener<? extends Future<? super V>> listener)	Removes the first occurrence of the specified listener from this future.
Promise<V>	removeListeners(GenericFutureListener<? extends Future<? super V>>... listeners)	Removes the first occurrence for each of the listeners from this future.
Promise<V>	setFailure(Throwable cause)	Marks this future as a failure and notifies all listeners.
Promise<V>	setSuccess(V result)	Marks this future as a success and notifies all listeners.
boolean	setUncancellable()	Make this future impossible to cancel.
Promise<V>	sync()	Waits for this future until it is done, and rethrows the cause of the failure if this future failed.
Promise<V>	syncUninterruptibly()	Waits for this future until it is done, and rethrows the cause of the failure if this future failed.
String	toString()
protected StringBuilder	toStringBuilder()
boolean	tryFailure(Throwable cause)	Marks this future as a failure and notifies all listeners.
boolean	trySuccess(V result)	Marks this future as a success and notifies all listeners.

Methods inherited from class java.lang.Object

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

Constructor Detail

DefaultPromise

public DefaultPromise(EventExecutor executor)

Creates a new instance. It is preferable to use EventExecutor.newPromise() to create a new promise

Parameters:

executor - the EventExecutor which is used to notify the promise once it is complete. It is assumed this executor will protect against StackOverflowError exceptions. The executor may be used to avoid StackOverflowError by executing a Runnable if the stack depth exceeds a threshold.

DefaultPromise

protected DefaultPromise()

See executor() for expectations of the executor.

Method Detail

setSuccess

public Promise<V> setSuccess(V result)

Description copied from interface: Promise

Marks this future as a success and notifies all listeners. If it is success or failed already it will throw an IllegalStateException.

Specified by:

setSuccess in interface Promise<V>

trySuccess

public boolean trySuccess(V result)

Description copied from interface: Promise

Marks this future as a success and notifies all listeners.

Specified by:

trySuccess in interface Promise<V>

Returns:

true if and only if successfully marked this future as a success. Otherwise false because this future is already marked as either a success or a failure.

setFailure

public Promise<V> setFailure(Throwable cause)

Description copied from interface: Promise

Marks this future as a failure and notifies all listeners. If it is success or failed already it will throw an IllegalStateException.

Specified by:

setFailure in interface Promise<V>

tryFailure

public boolean tryFailure(Throwable cause)

Description copied from interface: Promise

Marks this future as a failure and notifies all listeners.

Specified by:

tryFailure in interface Promise<V>

Returns:

true if and only if successfully marked this future as a failure. Otherwise false because this future is already marked as either a success or a failure.

setUncancellable

public boolean setUncancellable()

Description copied from interface: Promise

Make this future impossible to cancel.

Specified by:

setUncancellable in interface Promise<V>

Returns:

true if and only if successfully marked this future as uncancellable or it is already done without being cancelled. false if this future has been cancelled already.

isSuccess

public boolean isSuccess()

Description copied from interface: Future

Returns true if and only if the I/O operation was completed successfully.

Specified by:

isSuccess in interface Future<V>

isCancellable

public boolean isCancellable()

Description copied from interface: Future

returns true if and only if the operation can be cancelled via Future.cancel(boolean).

Specified by:

isCancellable in interface Future<V>

cause

public Throwable cause()

Description copied from interface: Future

Returns the cause of the failed I/O operation if the I/O operation has failed.

Specified by:

cause in interface Future<V>

Returns:

the cause of the failure. null if succeeded or this future is not completed yet.

addListener

public Promise<V> addListener(GenericFutureListener<? extends Future<? super V>> listener)

Description copied from interface: Future

Adds the specified listener to this future. The specified listener is notified when this future is done. If this future is already completed, the specified listener is notified immediately.

Specified by:

addListener in interface Future<V>

Specified by:

addListener in interface Promise<V>

addListeners

public Promise<V> addListeners(GenericFutureListener<? extends Future<? super V>>... listeners)

Description copied from interface: Future

Adds the specified listeners to this future. The specified listeners are notified when this future is done. If this future is already completed, the specified listeners are notified immediately.

Specified by:

addListeners in interface Future<V>

Specified by:

addListeners in interface Promise<V>

removeListener

public Promise<V> removeListener(GenericFutureListener<? extends Future<? super V>> listener)

Description copied from interface: Future

Removes the first occurrence of the specified listener from this future. The specified listener is no longer notified when this future is done. If the specified listener is not associated with this future, this method does nothing and returns silently.

Specified by:

removeListener in interface Future<V>

Specified by:

removeListener in interface Promise<V>

removeListeners

public Promise<V> removeListeners(GenericFutureListener<? extends Future<? super V>>... listeners)

Description copied from interface: Future

Removes the first occurrence for each of the listeners from this future. The specified listeners are no longer notified when this future is done. If the specified listeners are not associated with this future, this method does nothing and returns silently.

Specified by:

removeListeners in interface Future<V>

Specified by:

removeListeners in interface Promise<V>

await

public Promise<V> await()
                 throws InterruptedException

Description copied from interface: Future

Waits for this future to be completed.

Specified by:

await in interface Future<V>

Specified by:

await in interface Promise<V>

Throws:

InterruptedException - if the current thread was interrupted

awaitUninterruptibly

public Promise<V> awaitUninterruptibly()

Description copied from interface: Future

Waits for this future to be completed without interruption. This method catches an InterruptedException and discards it silently.

Specified by:

awaitUninterruptibly in interface Future<V>

Specified by:

awaitUninterruptibly in interface Promise<V>

await

public boolean await(long timeout,
                     TimeUnit unit)
              throws InterruptedException

Description copied from interface: Future

Waits for this future to be completed within the specified time limit.

Specified by:

await in interface Future<V>

Returns:

true if and only if the future was completed within the specified time limit

Throws:

InterruptedException - if the current thread was interrupted

await

public boolean await(long timeoutMillis)
              throws InterruptedException

Description copied from interface: Future

Waits for this future to be completed within the specified time limit.

Specified by:

await in interface Future<V>

Returns:

true if and only if the future was completed within the specified time limit

Throws:

InterruptedException - if the current thread was interrupted

awaitUninterruptibly

public boolean awaitUninterruptibly(long timeout,
                                    TimeUnit unit)

Description copied from interface: Future

Waits for this future to be completed within the specified time limit without interruption. This method catches an InterruptedException and discards it silently.

Specified by:

awaitUninterruptibly in interface Future<V>

Returns:

true if and only if the future was completed within the specified time limit

awaitUninterruptibly

public boolean awaitUninterruptibly(long timeoutMillis)

Description copied from interface: Future

Waits for this future to be completed within the specified time limit without interruption. This method catches an InterruptedException and discards it silently.

Specified by:

awaitUninterruptibly in interface Future<V>

Returns:

true if and only if the future was completed within the specified time limit

getNow

public V getNow()

Description copied from interface: Future

Return the result without blocking. If the future is not done yet this will return null. As it is possible that a null value is used to mark the future as successful you also need to check if the future is really done with Future.isDone() and not rely on the returned null value.

Specified by:

getNow in interface Future<V>

get

public V get()
      throws InterruptedException,
             ExecutionException

Specified by:

get in interface Future<V>

Overrides:

get in class AbstractFuture<V>

Throws:

InterruptedException

ExecutionException

get

public V get(long timeout,
             TimeUnit unit)
      throws InterruptedException,
             ExecutionException,
             TimeoutException

Specified by:

get in interface Future<V>

Overrides:

get in class AbstractFuture<V>

Throws:

InterruptedException

ExecutionException

TimeoutException

cancel

public boolean cancel(boolean mayInterruptIfRunning)

If the cancellation was successful it will fail the future with a CancellationException.

Specified by:

cancel in interface Future<V>

Specified by:

cancel in interface Future<V>

Parameters:

mayInterruptIfRunning - this value has no effect in this implementation.

isCancelled

public boolean isCancelled()

Specified by:

isCancelled in interface Future<V>

isDone

public boolean isDone()

Specified by:

isDone in interface Future<V>

sync

public Promise<V> sync()
                throws InterruptedException

Description copied from interface: Future

Waits for this future until it is done, and rethrows the cause of the failure if this future failed.

Specified by:

sync in interface Future<V>

Specified by:

sync in interface Promise<V>

Throws:

InterruptedException

syncUninterruptibly

public Promise<V> syncUninterruptibly()

Description copied from interface: Future

Waits for this future until it is done, and rethrows the cause of the failure if this future failed.

Specified by:

syncUninterruptibly in interface Future<V>

Specified by:

syncUninterruptibly in interface Promise<V>

toString

public String toString()

Overrides:

toString in class Object

toStringBuilder

protected StringBuilder toStringBuilder()

executor

protected EventExecutor executor()

Get the executor used to notify listeners when this promise is complete.

It is assumed this executor will protect against StackOverflowError exceptions. The executor may be used to avoid StackOverflowError by executing a Runnable if the stack depth exceeds a threshold.

Returns:

The executor used to notify listeners when this promise is complete.

checkDeadLock

protected void checkDeadLock()

notifyListener

protected static void notifyListener(EventExecutor eventExecutor,
                                     Future<?> future,
                                     GenericFutureListener<?> listener)

Notify a listener that a future has completed.

This method has a fixed depth of MAX_LISTENER_STACK_DEPTH that will limit recursion to prevent StackOverflowError and will stop notifying listeners added after this threshold is exceeded.

Parameters:

eventExecutor - the executor to use to notify the listener listener.

future - the future that is complete.

listener - the listener to notify.