groovyx.gpars.util

Class FQMessageQueue

java.lang.Object

groovyx.gpars.util.FQMessageQueue

All Implemented Interfaces:

MessageQueue

public final class FQMessageQueue
extends java.lang.Object
implements MessageQueue

An implementation of the message queue for actor and agent messaging using functional queues. It leverages the fact that in any moment there's only one reading thread accessing the queue and that potential read thread swap at the actor or agent thread pool synchronizes thread memory.

We also count on writers not to call the isEmpty() method

Author:

Vaclav Pech

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
(package private) static class	FQMessageQueue.EmptyNode
(package private) static class	FQMessageQueue.Node

Field Summary

Fields

Modifier and Type	Field and Description
private FQMessageQueue.Node	inside
private FQMessageQueue.Node	outside
private java.util.concurrent.atomic.AtomicReferenceFieldUpdater	outsideUpdater

Constructor Summary

Constructors

Constructor and Description
FQMessageQueue()

Method Summary

Modifier and Type	Method and Description
void	add(java.lang.Object element)
boolean	isEmpty()
java.lang.Object	poll()
private java.lang.Object	pollFromInside()

Methods inherited from class java.lang.Object

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

Field Detail

outside

private volatile FQMessageQueue.Node outside

inside

private FQMessageQueue.Node inside

outsideUpdater

private final java.util.concurrent.atomic.AtomicReferenceFieldUpdater outsideUpdater

Constructor Detail

FQMessageQueue

public FQMessageQueue()

Method Detail

isEmpty

public boolean isEmpty()

Specified by:

isEmpty in interface MessageQueue

poll

public java.lang.Object poll()

Specified by:

poll in interface MessageQueue

pollFromInside

private java.lang.Object pollFromInside()

add

public void add(java.lang.Object element)

Specified by:

add in interface MessageQueue