org.jasig.portal.utils
Class BlockingQueue

java.lang.Object
  org.jasig.portal.utils.BlockingQueue

public class BlockingQueue
extends java.lang.Object

A simple FIFO queue that has MIN/MAX capacity and that blocks if either enqueue/dequeue would result in violation of these limits. Default values for min/max are 0/infinite

Author:

Peter Kharchenko

Field Summary

(package private) int	maxSize
(package private) int	minSize
(package private) java.util.LinkedList	queue

Constructor Summary

BlockingQueue()

BlockingQueue(int max)

BlockingQueue(int min, int max)
Construct a new blocking queue with predefined max/min limits

Method Summary

java.lang.Object	dequeue() Remove object from the beginning of the queue
void	enqueue(java.lang.Object o) Add new object to the end of the queue
int	getMaxSize()
int	getMinSize()
void	setLimits(int max, int min) Set the queue limits.
void	setMaxSize(int max)
void	setMinSize(int min)
int	size()

Methods inherited from class java.lang.Object

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

Field Detail

maxSize

int maxSize

minSize

int minSize

queue

volatile java.util.LinkedList queue

Constructor Detail

BlockingQueue

BlockingQueue()

BlockingQueue

BlockingQueue(int min,
              int max)

Construct a new blocking queue with predefined max/min limits

BlockingQueue

BlockingQueue(int max)

Method Detail

enqueue

public void enqueue(java.lang.Object o)
             throws java.lang.InterruptedException

Add new object to the end of the queue

Parameters:

o - object to be placed on the queue

Throws:

java.lang.InterruptedException

dequeue

public java.lang.Object dequeue()
                         throws java.lang.InterruptedException

Remove object from the beginning of the queue

Throws:

java.lang.InterruptedException - if the wait was interrupted

setLimits

public void setLimits(int max,
                      int min)

Set the queue limits. To specify a queue without an upper bound (that is max=inifinity) use max value of -1

getMaxSize

public int getMaxSize()

getMinSize

public int getMinSize()

setMaxSize

public void setMaxSize(int max)

setMinSize

public void setMinSize(int min)

size

public int size()