org.jgroups.blocks.executor

Class ExecutionService.DistributedFuture<V>

java.lang.Object

org.jgroups.blocks.executor.ExecutionService.DistributedFuture<V>

Type Parameters:

V -

All Implemented Interfaces:

java.lang.Runnable, java.util.concurrent.Future<V>, java.util.concurrent.RunnableFuture<V>, ExecutorNotification, NotifyingFuture<V>

Enclosing class:

ExecutionService

public static class ExecutionService.DistributedFuture<V>
extends java.lang.Object
implements java.util.concurrent.RunnableFuture<V>, ExecutorNotification, NotifyingFuture<V>

This is basically a copy of the FutureTask in java.util.concurrent but added serializable to it. Also added in the NotifyingFuture so that the channel can update the future when the value is calculated.

Author:

wburns

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
protected static class	ExecutionService.DistributedFuture.Sync<V> Synchronization control for FutureTask.

Field Summary

Fields

Modifier and Type	Field and Description
protected ExecutionService.DistributedFuture.Sync<V>	sync Synchronization control for FutureTask

Constructor Summary

Constructors

Constructor and Description
DistributedFuture(Channel channel, java.util.concurrent.locks.Lock unfinishedLock, java.util.concurrent.locks.Condition condition, java.util.Set<java.util.concurrent.Future<?>> futuresToFinish, java.util.concurrent.Callable<V> callable) Creates a FutureTask that will upon running, execute the given Callable.
DistributedFuture(Channel channel, java.util.concurrent.locks.Lock unfinishedLock, java.util.concurrent.locks.Condition condition, java.util.Set<java.util.concurrent.Future<?>> futuresToFinish, java.lang.Runnable runnable, V result) Creates a FutureTask that will upon running, execute the given Runnable, and arrange that get will return the given result on successful completion.

Method Summary

Modifier and Type	Method and Description
boolean	cancel(boolean mayInterruptIfRunning)
protected void	done() Protected method invoked when this task transitions to state isDone (whether normally or via cancellation).
V	get()
V	get(long timeout, java.util.concurrent.TimeUnit unit)
java.util.concurrent.Callable<V>	getCallable()
void	interrupted(java.lang.Runnable runnable)
boolean	isCancelled()
boolean	isDone()
void	resultReturned(java.lang.Object obj)
void	run() Sets this Future to the result of its computation unless it has been cancelled.
protected void	set(V v) Sets the result of this Future to the given value unless this future has already been set or has been cancelled.
protected void	setException(java.lang.Throwable t) Causes this future to report an ExecutionException with the given throwable as its cause, unless this Future has already been set or has been cancelled.
NotifyingFuture<V>	setListener(FutureListener<V> listener) Attaches a listener and returns the same future instance, to allow for 'building' futures.
void	throwableEncountered(java.lang.Throwable t)
java.lang.String	toString()

Methods inherited from class java.lang.Object

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

Field Detail

sync

protected final ExecutionService.DistributedFuture.Sync<V> sync

Synchronization control for FutureTask

Constructor Detail

DistributedFuture

public DistributedFuture(Channel channel,
                         java.util.concurrent.locks.Lock unfinishedLock,
                         java.util.concurrent.locks.Condition condition,
                         java.util.Set<java.util.concurrent.Future<?>> futuresToFinish,
                         java.util.concurrent.Callable<V> callable)

Creates a FutureTask that will upon running, execute the given Callable.

Parameters:

channel - The channel that messages are sent down

unfinishedLock - The lock which protects the futuresToFinish set object.

condition - The condition to signal when this future finishes

futuresToFinish - The set to remove this future from when it is finished.

callable - The callable to actually run on the server side

DistributedFuture

public DistributedFuture(Channel channel,
                         java.util.concurrent.locks.Lock unfinishedLock,
                         java.util.concurrent.locks.Condition condition,
                         java.util.Set<java.util.concurrent.Future<?>> futuresToFinish,
                         java.lang.Runnable runnable,
                         V result)

Creates a FutureTask that will upon running, execute the given Runnable, and arrange that get will return the given result on successful completion.

Parameters:

channel - The channel that messages are sent down

unfinishedLock - The lock which protects the futuresToFinish set object.

condition - The condition to signal when this future finishes

futuresToFinish - The set to remove this future from when it is finished.

runnable - the runnable task

result - the result to return on successful completion. If you don't need a particular result, consider using constructions of the form: Future<?> f = new FutureTask<Object>(runnable, null)

Throws:

java.lang.NullPointerException - if runnable is null

Method Detail

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

getCallable

public java.util.concurrent.Callable<V> getCallable()

isCancelled

public boolean isCancelled()

Specified by:

isCancelled in interface java.util.concurrent.Future<V>

isDone

public boolean isDone()

Specified by:

isDone in interface java.util.concurrent.Future<V>

cancel

public boolean cancel(boolean mayInterruptIfRunning)

Specified by:

cancel in interface java.util.concurrent.Future<V>

get

public V get()
      throws java.lang.InterruptedException,
             java.util.concurrent.ExecutionException

Specified by:

get in interface java.util.concurrent.Future<V>

Throws:

java.util.concurrent.CancellationException

java.lang.InterruptedException

java.util.concurrent.ExecutionException

get

public V get(long timeout,
             java.util.concurrent.TimeUnit unit)
      throws java.lang.InterruptedException,
             java.util.concurrent.ExecutionException,
             java.util.concurrent.TimeoutException

Specified by:

get in interface java.util.concurrent.Future<V>

Throws:

java.util.concurrent.CancellationException

java.lang.InterruptedException

java.util.concurrent.ExecutionException

java.util.concurrent.TimeoutException

done

protected void done()

Protected method invoked when this task transitions to state isDone (whether normally or via cancellation). The default implementation does nothing. Subclasses may override this method to invoke completion callbacks or perform bookkeeping. Note that you can query status inside the implementation of this method to determine whether this task has been cancelled.

setListener

public NotifyingFuture<V> setListener(FutureListener<V> listener)

Description copied from interface: NotifyingFuture

Attaches a listener and returns the same future instance, to allow for 'building' futures.

Specified by:

setListener in interface NotifyingFuture<V>

Parameters:

listener - listener to attach

Returns:

the same future instance

set

protected void set(V v)

Sets the result of this Future to the given value unless this future has already been set or has been cancelled. This method is invoked internally by the run method upon successful completion of the computation.

Parameters:

v - the value

setException

protected void setException(java.lang.Throwable t)

Causes this future to report an ExecutionException with the given throwable as its cause, unless this Future has already been set or has been cancelled. This method is invoked internally by the run method upon failure of the computation.

Parameters:

t - the cause of failure

run

public void run()

Sets this Future to the result of its computation unless it has been cancelled.

Specified by:

run in interface java.lang.Runnable

Specified by:

run in interface java.util.concurrent.RunnableFuture<V>

resultReturned

public void resultReturned(java.lang.Object obj)

Specified by:

resultReturned in interface ExecutorNotification

throwableEncountered

public void throwableEncountered(java.lang.Throwable t)

Specified by:

throwableEncountered in interface ExecutorNotification

interrupted

public void interrupted(java.lang.Runnable runnable)

Specified by:

interrupted in interface ExecutorNotification