nl.justobjects.pushlet.core
Class EventQueue

java.lang.Object
  nl.justobjects.pushlet.core.EventQueue

public class EventQueue

extends java.lang.Object

FIFO queue with guarded suspension. Purpose

Implementation
FIFO queue class implemented with circular array. The enQueue() and deQueue() methods use guarded suspension according to a readers/writers pattern, implemented with java.lang.Object.wait()/notify().

Examples

Version:

$Id: EventQueue.java,v 1.3 2007/11/23 14:33:07 justb Exp $

Author:

Just van den Broecke - Just Objects ©

Field Summary

private int	capacity Defines maximum queue size
private int	front
private Event[]	queue
private int	rear

Constructor Summary

EventQueue()
Construct queue with default (8) capacity.

EventQueue(int capacity)
Construct queue with specified capacity.

Method Summary

Event	deQueue() Get head; if empty wait until something in queue.
Event	deQueue(long maxWaitTime) Get head; if empty wait for specified time at max.
Event[]	deQueueAll(long maxWaitTime) Get all queued Events.
boolean	enQueue(Event item) Put item in queue; waits() indefinitely if queue is full.
boolean	enQueue(Event item, long maxWaitTime) Put item in queue; if full wait maxtime.
private Event	fetchNext() Circular counter.
int	getSize()
boolean	isEmpty() Is the queue empty ?
boolean	isFull() Is the queue full ?
static void	main(java.lang.String[] args)
private int	next(int index) Circular counter.
static void	p(java.lang.String s)

Methods inherited from class java.lang.Object

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

Field Detail

capacity

private int capacity

Defines maximum queue size

queue

private Event[] queue

front

private int front

rear

private int rear

Constructor Detail

EventQueue

public EventQueue()

Construct queue with default (8) capacity.

EventQueue

public EventQueue(int capacity)

Construct queue with specified capacity.

Method Detail

enQueue

public boolean enQueue(Event item)
                throws java.lang.InterruptedException

Put item in queue; waits() indefinitely if queue is full.

Throws:

java.lang.InterruptedException

enQueue

public boolean enQueue(Event item,
                       long maxWaitTime)
                throws java.lang.InterruptedException

Put item in queue; if full wait maxtime.

Throws:

java.lang.InterruptedException

deQueue

public Event deQueue()
              throws java.lang.InterruptedException

Get head; if empty wait until something in queue.

Throws:

java.lang.InterruptedException

deQueue

public Event deQueue(long maxWaitTime)
              throws java.lang.InterruptedException

Get head; if empty wait for specified time at max.

Throws:

java.lang.InterruptedException

deQueueAll

public Event[] deQueueAll(long maxWaitTime)
                   throws java.lang.InterruptedException

Get all queued Events.

Throws:

java.lang.InterruptedException

getSize

public int getSize()

isEmpty

public boolean isEmpty()

Is the queue empty ?

isFull

public boolean isFull()

Is the queue full ?

next

private int next(int index)

Circular counter.

fetchNext

private Event fetchNext()

Circular counter.

p

public static void p(java.lang.String s)

main

public static void main(java.lang.String[] args)