edu.vub.at.actors.eventloops
Class BlockingFuture

java.lang.Object
  edu.vub.at.actors.eventloops.BlockingFuture

All Implemented Interfaces:

Future

public final class BlockingFuture

extends java.lang.Object

implements Future

A BlockingFuture represents a synchronous, blocking future used by the AT/2 implementation to synchronize between native threads. Usage: BlockingFuture future = object.doAsynchronousComputation(); try { Object result = future.get(); } catch(Exception e) { // async computation raised an exception } Based on source code written by Doug Lea with assistance from members of JCP JSR-166 Expert Group and released to the public domain.

Author:

tvcutsem

Field Summary

private java.lang.Exception	exception
private boolean	fulfilled
private java.lang.Object	result

Constructor Summary

BlockingFuture()

Method Summary

java.lang.Object	get() Used to retrieve the real value from the future.
private java.lang.Object	getResult() Gets the result of the task.
boolean	isDetermined()
void	resolve(java.lang.Object v) Sets the result of this Future to the given value unless this future has already been set or has been cancelled.
void	ruin(java.lang.Exception e) 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.
private void	setCompleted(java.lang.Object result) Marks the task as completed.
private void	setFailed(java.lang.Exception exception) Marks the task as failed.
private void	waitFor() Waits for the task to complete.

Methods inherited from class java.lang.Object

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

Field Detail

result

private java.lang.Object result

exception

private java.lang.Exception exception

fulfilled

private boolean fulfilled

Constructor Detail

BlockingFuture

public BlockingFuture()

Method Detail

isDetermined

public boolean isDetermined()

get

public java.lang.Object get()
                     throws java.lang.Exception

Description copied from interface: Future

Used to retrieve the real value from the future.

Specified by:

get in interface Future

Returns:

the resolved value of the future, once it is available.

Throws:

java.lang.Exception - if the future has been ruined with an exception.

resolve

public void resolve(java.lang.Object v)

Sets the result of this Future to the given value unless this future has already been set or has been cancelled.

Specified by:

resolve in interface Future

Parameters:

v - the value

ruin

public void ruin(java.lang.Exception e)

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.

Specified by:

ruin in interface Future

Parameters:

e - the cause of failure

setCompleted

private void setCompleted(java.lang.Object result)

Marks the task as completed.

Parameters:

result - the result of a task.

setFailed

private void setFailed(java.lang.Exception exception)

Marks the task as failed.

Parameters:

exception - the cause of abrupt completion.

waitFor

private void waitFor()

Waits for the task to complete. PRE: lock owned

getResult

private java.lang.Object getResult()
                            throws java.lang.Exception

Gets the result of the task. PRE: task completed PRE: lock owned

Throws:

java.lang.Exception