edu.rice.cs.plt.concurrent
Class FutureTaskController<T>

java.lang.Object
  edu.rice.cs.plt.concurrent.TaskController<R>
      edu.rice.cs.plt.concurrent.PollingTaskController<T>
          edu.rice.cs.plt.concurrent.FutureTaskController<T>

All Implemented Interfaces:

ResolvingThunk<T>, Thunk<T>, Future<T>

public class FutureTaskController<T>
extends PollingTaskController<T>

Treats an arbitrary Future-producing computation as a TaskController. The task is considered "started" once the future has been created via TaskController.start() (even though some futures are not scheduled for immediate execution — the API provides no means for determining whether a task is actually running).

Nested Class Summary

Nested classes/interfaces inherited from class edu.rice.cs.plt.concurrent.PollingTaskController

PollingTaskController.PollingCancelingState, PollingTaskController.PollingRunningState

Nested classes/interfaces inherited from class edu.rice.cs.plt.concurrent.TaskController

TaskController.CanceledStartingState, TaskController.CanceledState, TaskController.CancelingState, TaskController.CleanlyFinishedState, TaskController.ComputingState, TaskController.ExecutionExceptionState, TaskController.FinishedState, TaskController.FreshStartingState, TaskController.FreshState, TaskController.InternalExceptionState, TaskController.RunningState, TaskController.StartingState, TaskController.State, TaskController.Status, TaskController.WaitingState

Field Summary

Fields inherited from class edu.rice.cs.plt.concurrent.TaskController

state

Constructor Summary

FutureTaskController(Thunk<? extends Future<? extends T>> futureThunk)

Method Summary

protected void	discard() Clean up after the task has completed.
protected void	doStart() Begin computation and call TaskController.started().
protected void	doStop() Terminate computation and call TaskController.stopped().
protected void	finish() Block until the task is complete or this thread is interrupted.
protected void	finish(long timeout, TimeUnit unit) Block until the task is complete, this thread is interrupted, or the given timeout is reached.
protected void	update() Check the current status and call the appropriate method if the task is complete.

Methods inherited from class edu.rice.cs.plt.concurrent.PollingTaskController

finishListeners, runningState

Methods inherited from class edu.rice.cs.plt.concurrent.TaskController

attemptGet, attemptGet, cancel, cancel, finishedCleanly, finishedWithImplementationException, finishedWithTaskException, get, get, get, hasValue, isCanceled, isCancelled, isDone, isResolved, start, started, status, stopped, value

Methods inherited from class java.lang.Object

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

Constructor Detail

FutureTaskController

public FutureTaskController(Thunk<? extends Future<? extends T>> futureThunk)

Method Detail

doStart

protected void doStart()

Description copied from class: TaskController

Begin computation and call TaskController.started(). If starting does not occur immediately (for example, blocking occurs first), the started() call may occur in a different thread.

Specified by:

doStart in class TaskController<T>

doStop

protected void doStop()

Description copied from class: TaskController

Terminate computation and call TaskController.stopped(). Never called before started() has been invoked. If termination does not occur immediately (for example, blocking occurs first), the stopped() call may occur in a different thread.

Specified by:

doStop in class TaskController<T>

discard

protected void discard()

Description copied from class: TaskController

Clean up after the task has completed. Called whenever the task enters a canceled or finished state (for example, when finishedCleanly() has been called, or when cancel() is invoked on a PAUSED controller). By default, does nothing, but can be overridden to close connections or throw away unnecessary objects. (Where TaskControllers live far beyond their computation life span (as simple wrappers for a value), this allows objects related to the computation to be garbage-collected in the interim.)

Overrides:

discard in class TaskController<T>

update

protected void update()

Description copied from class: PollingTaskController

Check the current status and call the appropriate method if the task is complete. This method is invoked frequently and should not block.

Specified by:

update in class PollingTaskController<T>

finish

protected void finish()
               throws InterruptedException

Description copied from class: PollingTaskController

Block until the task is complete or this thread is interrupted. Must not return until after one of the completion methods are called.

Specified by:

finish in class PollingTaskController<T>

Throws:

InterruptedException

finish

protected void finish(long timeout,
                      TimeUnit unit)
               throws InterruptedException,
                      TimeoutException

Description copied from class: PollingTaskController

Block until the task is complete, this thread is interrupted, or the given timeout is reached. Must not return until after one of the completion methods are called.

Specified by:

finish in class PollingTaskController<T>

Throws:

InterruptedException

TimeoutException