regionQueue
Class ServerQueue

java.lang.Object
  java.util.AbstractCollection
      com.gemstone.bp.edu.emory.mathcs.backport.java.util.AbstractCollection
          com.gemstone.bp.edu.emory.mathcs.backport.java.util.AbstractQueue
              regionQueue.ServerQueue

All Implemented Interfaces:

com.gemstone.bp.edu.emory.mathcs.backport.java.util.concurrent.BlockingQueue, com.gemstone.bp.edu.emory.mathcs.backport.java.util.Queue, Iterable, Collection

public class ServerQueue
extends com.gemstone.bp.edu.emory.mathcs.backport.java.util.AbstractQueue
implements com.gemstone.bp.edu.emory.mathcs.backport.java.util.concurrent.BlockingQueue

The server side of a distributed queue. The server holds the contents of a queue in a RegionQueue that may be backed up in other servers. It receives clients' requests to add and remove items from the queue via a "communication region" that has a special CacheLoader and CacheWriter that interact with the queue.

This class implements the BlockingQueue interface so it can be treated as a queue. However, it delegates all of the queue-related functionality to the underlying RegionQueue.

Since:

4.1

Author:

GemStone Systems, Inc.

Nested Class Summary

(package private) class	ServerQueue.QueueLoader A CacheLoader that perform some "get"-related operation on the RegionQueue.
(package private) class	ServerQueue.QueueWriter A CacheWriter that adds an element to the tail of the queue.

Field Summary

(package private) static String	COMM_REGION_NAME The name of the subregion used for communication.
protected String	name The name of this queue
protected RegionQueue	regionQueue The region queue that stores the contents of this distributed queue.

Constructor Summary

ServerQueue(String name, int capacity, DistributedSystem system, int port)
Creates a new ServerQueue whose contents is available to ClientQueue via the given port.

Method Summary

void	close() Closes this ServerQueue and releases all resources held by it including the Cache and all regions.
int	drainTo(Collection c)
int	drainTo(Collection c, int maxElements)
String	getName()
boolean	isEmpty()
Iterator	iterator()
static void	main(String[] args) A main program that creates a ServerQueue.
boolean	offer(Object o)
boolean	offer(Object o, long timeout, com.gemstone.bp.edu.emory.mathcs.backport.java.util.concurrent.TimeUnit unit)
Object	peek()
Object	poll()
Object	poll(long timeout, com.gemstone.bp.edu.emory.mathcs.backport.java.util.concurrent.TimeUnit unit)
void	put(Object o)
int	remainingCapacity()
int	size()
Object	take()
Object[]	toArray()
Object[]	toArray(Object[] array)
String	toString()

Methods inherited from class com.gemstone.bp.edu.emory.mathcs.backport.java.util.AbstractQueue

add, addAll, clear, element, remove

Methods inherited from class java.util.AbstractCollection

contains, containsAll, remove, removeAll, retainAll

Methods inherited from class java.lang.Object

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

Methods inherited from interface com.gemstone.bp.edu.emory.mathcs.backport.java.util.concurrent.BlockingQueue

add, contains, remove

Methods inherited from interface com.gemstone.bp.edu.emory.mathcs.backport.java.util.Queue

element, remove

Methods inherited from interface java.util.Collection

addAll, clear, containsAll, equals, hashCode, removeAll, retainAll

Field Detail

COMM_REGION_NAME

static final String COMM_REGION_NAME

The name of the subregion used for communication. It is package protected so that other classe scan share it.

See Also:

Constant Field Values

name

protected final String name

The name of this queue

regionQueue

protected final RegionQueue regionQueue

The region queue that stores the contents of this distributed queue.

Constructor Detail

ServerQueue

public ServerQueue(String name,
                   int capacity,
                   DistributedSystem system,
                   int port)
            throws TimeoutException

Creates a new ServerQueue whose contents is available to ClientQueue via the given port.

Parameters:

name - The name of the distributed queue

system - The distributed system to which the queue belongs

port - The port on which clients connect to the queue

capacity - The maximum number of elements allowed in the queue

Throws:

TimeoutException - If a cache access times out which creating the queue

IllegalStateException - If the state of the cache prevents the queue from being created

Method Detail

close

public void close()

Closes this ServerQueue and releases all resources held by it including the Cache and all regions.

put

public void put(Object o)
         throws InterruptedException

Specified by:

put in interface com.gemstone.bp.edu.emory.mathcs.backport.java.util.concurrent.BlockingQueue

Throws:

InterruptedException

take

public Object take()
            throws InterruptedException

Specified by:

take in interface com.gemstone.bp.edu.emory.mathcs.backport.java.util.concurrent.BlockingQueue

Throws:

InterruptedException

peek

public Object peek()

Specified by:

peek in interface com.gemstone.bp.edu.emory.mathcs.backport.java.util.Queue

isEmpty

public boolean isEmpty()

Specified by:

isEmpty in interface Collection

Overrides:

isEmpty in class AbstractCollection

poll

public Object poll()

Specified by:

poll in interface com.gemstone.bp.edu.emory.mathcs.backport.java.util.Queue

size

public int size()

Specified by:

size in interface Collection

Specified by:

size in class AbstractCollection

toArray

public Object[] toArray(Object[] array)

Specified by:

toArray in interface Collection

Overrides:

toArray in class com.gemstone.bp.edu.emory.mathcs.backport.java.util.AbstractCollection

toArray

public Object[] toArray()

Specified by:

toArray in interface Collection

Overrides:

toArray in class com.gemstone.bp.edu.emory.mathcs.backport.java.util.AbstractCollection

poll

public Object poll(long timeout,
                   com.gemstone.bp.edu.emory.mathcs.backport.java.util.concurrent.TimeUnit unit)
            throws InterruptedException

Specified by:

poll in interface com.gemstone.bp.edu.emory.mathcs.backport.java.util.concurrent.BlockingQueue

Throws:

InterruptedException

offer

public boolean offer(Object o)

Specified by:

offer in interface com.gemstone.bp.edu.emory.mathcs.backport.java.util.concurrent.BlockingQueue

Specified by:

offer in interface com.gemstone.bp.edu.emory.mathcs.backport.java.util.Queue

offer

public boolean offer(Object o,
                     long timeout,
                     com.gemstone.bp.edu.emory.mathcs.backport.java.util.concurrent.TimeUnit unit)
              throws InterruptedException

Specified by:

offer in interface com.gemstone.bp.edu.emory.mathcs.backport.java.util.concurrent.BlockingQueue

Throws:

InterruptedException

remainingCapacity

public int remainingCapacity()

Specified by:

remainingCapacity in interface com.gemstone.bp.edu.emory.mathcs.backport.java.util.concurrent.BlockingQueue

iterator

public Iterator iterator()

Specified by:

iterator in interface Iterable

Specified by:

iterator in interface Collection

Specified by:

iterator in class AbstractCollection

drainTo

public int drainTo(Collection c)

Specified by:

drainTo in interface com.gemstone.bp.edu.emory.mathcs.backport.java.util.concurrent.BlockingQueue

drainTo

public int drainTo(Collection c,
                   int maxElements)

Specified by:

drainTo in interface com.gemstone.bp.edu.emory.mathcs.backport.java.util.concurrent.BlockingQueue

getName

public String getName()

toString

public String toString()

Overrides:

toString in class AbstractCollection

main

public static void main(String[] args)
                 throws Throwable

A main program that creates a ServerQueue.

Throws:

Throwable