Modifier and Type	Class and Description
private static class	JdkFutureAdapters.ListenableFutureAdapter<V extends @Nullable Object> An adapter to turn a `Future` into a `ListenableFuture`.

Access	Constructor and Description
private	JdkFutureAdapters()

Modifier and Type	Method and Description
public static <V extends @Nullable Object> ListenableFuture<V>	listenInPoolThread(Future<V> future) Assigns a thread to the given `Future` to provide `ListenableFuture` functionality.
public static <V extends @Nullable Object> ListenableFuture<V>	listenInPoolThread(Future<V> future, Executor executor) Submits a blocking task for the given `Future` to provide `ListenableFuture` functionality.

JdkFutureAdapters	back to summary
private JdkFutureAdapters()

Method Detail

listenInPoolThread back to summary

listenInPoolThread	back to summary
public static <V extends @Nullable Object> ListenableFuture<V> listenInPoolThread(Future<V> future) Assigns a thread to the given `Future` to provide `ListenableFuture` functionality. Warning If the input future does not already implement `ListenableFuture`, the returned future will emulate `ListenableFuture#addListener` by taking a thread from an internal, unbounded pool at the first call to `addListener` and holding it until the future is done. Prefer to create `ListenableFuture` instances with `SettableFuture`, `MoreExecutors#listeningDecorator(java.util.concurrent.ExecutorService)`, `ListenableFutureTask`, `AbstractFuture`, and other utilities over creating plain `Future` instances to be upgraded to `ListenableFuture` after the fact.

public static <V extends @Nullable Object> ListenableFuture<V> listenInPoolThread(Future<V> future)

Assigns a thread to the given Future to provide ListenableFuture functionality.

Warning

If the input future does not already implement ListenableFuture, the returned future will emulate ListenableFuture#addListener by taking a thread from an internal, unbounded pool at the first call to addListener and holding it until the future is done.

Prefer to create ListenableFuture instances with SettableFuture, MoreExecutors#listeningDecorator(java.util.concurrent.ExecutorService), ListenableFutureTask, AbstractFuture, and other utilities over creating plain Future instances to be upgraded to ListenableFuture after the fact.

listenInPoolThread back to summary

listenInPoolThread	back to summary
public static <V extends @Nullable Object> ListenableFuture<V> listenInPoolThread(Future<V> future, Executor executor) Submits a blocking task for the given `Future` to provide `ListenableFuture` functionality. Warning If the input future does not already implement `ListenableFuture`, the returned future will emulate `ListenableFuture#addListener` by submitting a task to the given executor at the first call to `addListener`. The task must be started by the executor promptly, or else the returned `ListenableFuture` may fail to work. The task's execution consists of blocking until the input future is done, so each call to this method may claim and hold a thread for an arbitrary length of time. Use of bounded executors or other executors that may fail to execute a task promptly may result in deadlocks. Prefer to create `ListenableFuture` instances with `SettableFuture`, `MoreExecutors#listeningDecorator(java.util.concurrent.ExecutorService)`, `ListenableFutureTask`, `AbstractFuture`, and other utilities over creating plain `Future` instances to be upgraded to `ListenableFuture` after the fact. Since 12.0

public static <V extends @Nullable Object> ListenableFuture<V> listenInPoolThread(Future<V> future, Executor executor)

Submits a blocking task for the given Future to provide ListenableFuture functionality.

Warning

If the input future does not already implement ListenableFuture, the returned future will emulate ListenableFuture#addListener by submitting a task to the given executor at the first call to addListener. The task must be started by the executor promptly, or else the returned ListenableFuture may fail to work. The task's execution consists of blocking until the input future is done, so each call to this method may claim and hold a thread for an arbitrary length of time. Use of bounded executors or other executors that may fail to execute a task promptly may result in deadlocks.

Since: 12.0

com.google.common.util.concurrent back to summary

private Class JdkFutureAdapters.ListenableFutureAdapter<V extends @Nullable Object>

Class Inheritance

extends ForwardingFuture<V extends @Nullable Object>
implements ListenableFuture<V extends @Nullable Object>

java.lang.Object
com.google.common.collect.ForwardingObject
com.google.common.util.concurrent.ForwardingFuture
com.google.common.util.concurrent.JdkFutureAdapters.ListenableFutureAdapter

All Implemented Interfaces

com.google.common.util.concurrent.ListenableFuture, java.util.concurrent.Future

An adapter to turn a Future into a ListenableFuture. This will wait on the future to finish, and when it completes, run the listeners. This implementation will wait on the source future indefinitely, so if the source future never completes, the adapter will never complete either.

If the delegate future is interrupted or throws an unexpected unchecked exception, the listeners will not be invoked.

Field Summary

Modifier and Type	Field and Description
private final Executor	adapterExecutor
private static final Executor	defaultAdapterExecutor
private final Future<V>	delegate
private final ExecutionList	executionList
private final AtomicBoolean	hasListeners
private static final ThreadFactory	threadFactory

Constructor Summary

Access	Constructor and Description
pack-priv	ListenableFutureAdapter(Future<V> delegate)
pack-priv	ListenableFutureAdapter(Future<V> delegate, Executor adapterExecutor)

Method Summary

Modifier and Type	Method and Description
public void	addListener(Runnable the listener to run when the computation is complete listener, Executor the executor to run the listener in exec) Implements com.google.common.util.concurrent.ListenableFuture.addListener. Registers a listener to be run on the given executor.
protected Future<V>	delegate() Implements abstract com.google.common.util.concurrent.ForwardingFuture.delegate. Returns the backing delegate instance that methods are forwarded to.

Inherited from com.google.common.util.concurrent.ForwardingFuture:: cancel get get isCancelled isDone

Field Detail

adapterExecutor	back to summary
private final Executor adapterExecutor

defaultAdapterExecutor	back to summary
private static final Executor defaultAdapterExecutor

delegate	back to summary
private final Future<V> delegate

executionList	back to summary
private final ExecutionList executionList

hasListeners	back to summary
private final AtomicBoolean hasListeners

threadFactory	back to summary
private static final ThreadFactory threadFactory

Constructor Detail

ListenableFutureAdapter	back to summary
pack-priv ListenableFutureAdapter(Future<V> delegate)

ListenableFutureAdapter	back to summary
pack-priv ListenableFutureAdapter(Future<V> delegate, Executor adapterExecutor)

Method Detail

addListener back to summary

addListener	back to summary
public void addListener(Runnable listener, Executor exec) Implements com.google.common.util.concurrent.ListenableFuture.addListener. Doc from com.google.common.util.concurrent.ListenableFuture.addListener. Registers a listener to be run on the given executor. The listener will run when the `Future`'s computation is complete or, if the computation is already complete, immediately. There is no guaranteed ordering of execution of listeners, but any listener added through this method is guaranteed to be called once the computation is complete. Exceptions thrown by a listener will be propagated up to the executor. Any exception thrown during `Executor.execute` (e.g., a `RejectedExecutionException` or an exception thrown by direct execution) will be caught and logged. Note If your listener is lightweight -- and will not cause stack overflow by completing more futures or adding more `directExecutor()` listeners inline -- consider `MoreExecutors#directExecutor`. Otherwise, avoid it: See the warnings on the docs for `directExecutor`. This is the most general listener interface. For common operations performed using listeners, see `Futures`. For a simplified but general listener interface, see `addCallback()`. Memory consistency effects: Actions in a thread prior to adding a listener happen-before its execution begins, perhaps in another thread. Guava implementations of `ListenableFuture` promptly release references to listeners after executing them. Parameters listener:Runnable the listener to run when the computation is complete exec:Executor the executor to run the listener in Annotations @Override

public void addListener(Runnable listener, Executor exec)

Implements com.google.common.util.concurrent.ListenableFuture.addListener.

Doc from com.google.common.util.concurrent.ListenableFuture.addListener.

Registers a listener to be run on the given executor. The listener will run when the Future's computation is complete or, if the computation is already complete, immediately.

There is no guaranteed ordering of execution of listeners, but any listener added through this method is guaranteed to be called once the computation is complete.

Exceptions thrown by a listener will be propagated up to the executor. Any exception thrown during Executor.execute (e.g., a RejectedExecutionException or an exception thrown by direct execution) will be caught and logged.

Note

If your listener is lightweight -- and will not cause stack overflow by completing more futures or adding more directExecutor() listeners inline -- consider MoreExecutors#directExecutor. Otherwise, avoid it: See the warnings on the docs for directExecutor.

This is the most general listener interface. For common operations performed using listeners, see Futures. For a simplified but general listener interface, see addCallback().

Memory consistency effects: Actions in a thread prior to adding a listener happen-before its execution begins, perhaps in another thread.

Guava implementations of ListenableFuture promptly release references to listeners after executing them.

Parameters

listener:Runnable: the listener to run when the computation is complete
exec:Executor: the executor to run the listener in

Annotations

@Override

delegate back to summary

delegate	back to summary
protected Future<V> delegate() Implements abstract com.google.common.util.concurrent.ForwardingFuture.delegate. Doc from com.google.common.collect.ForwardingObject.delegate. Returns the backing delegate instance that methods are forwarded to. Abstract subclasses generally override this method with an abstract method that has a more specific return type, such as `ForwardingSet#delegate`. Concrete subclasses override this method to supply the instance being decorated. Annotations @Override

protected Future<V> delegate()

Implements abstract com.google.common.util.concurrent.ForwardingFuture.delegate.

Doc from com.google.common.collect.ForwardingObject.delegate.

Returns the backing delegate instance that methods are forwarded to. Abstract subclasses generally override this method with an abstract method that has a more specific return type, such as ForwardingSet#delegate. Concrete subclasses override this method to supply the instance being decorated.

Annotations

@Override

public final Class JdkFutureAdapters

Nested and Inner Type Summary

Constructor Summary

Method Summary

Constructor Detail

Method Detail

private Class JdkFutureAdapters.ListenableFutureAdapter<V extends @Nullable Object>

Field Summary

Constructor Summary

Method Summary

Field Detail

Constructor Detail

Method Detail