@Beta public final class JdkFutureAdapters extends Object
Utilities necessary for working with libraries that supply plain Future
instances. Note that, whenver possible, it is strongly preferred to modify those libraries to return ListenableFuture
directly.
Futures.makeListenable
, which existed in 1.0)Modifier and Type | Method and Description |
---|---|
static <V> ListenableFuture<V> |
listenInPoolThread(Future<V> future)
Assigns a thread to the given
Future to provide ListenableFuture functionality. |
static <V> ListenableFuture<V> |
listenInPoolThread(Future<V> future,
Executor executor)
Submits a blocking task for the given
Future to provide ListenableFuture functionality. |
public static <V> 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(java.lang.Runnable, java.util.concurrent.Executor)
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> 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(java.lang.Runnable, java.util.concurrent.Executor)
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.