/*
* JacORB - a free Java ORB
*
* Copyright (C) 1999-2014 Gerald Brose / The JacORB Team.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the Free
* Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*
*/
package org.jacorb.notification.queue;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import org.jacorb.notification.interfaces.Message;
import org.jacorb.notification.queue.MessageQueue.DiscardListener;
import java.util.concurrent.locks.ReadWriteLock;
import java.util.concurrent.locks.ReentrantReadWriteLock;
/**
* @author Alphonse Bendt
*/
public class RWLockEventQueueDecorator implements MessageQueueAdapter
{
private final List listeners_ = new ArrayList();
/**
* lock variable used to control access to the reference to the pending messages queue.
*/
private final ReadWriteLock delegateLock_ = new ReentrantReadWriteLock();
/**
* multithreaded access to this member is protected by delegateLock__
*/
private MessageQueueAdapter delegate_;
/**
*
*/
public RWLockEventQueueDecorator(MessageQueueAdapter initialDelegate)
{
super();
delegateLock_.writeLock().lock();
try
{
delegate_ = initialDelegate;
} finally
{
delegateLock_.writeLock().unlock();
}
}
public void replaceDelegate(MessageQueueAdapter newDelegate) throws InterruptedException
{
delegateLock_.writeLock().lock();
try
{
for (final Iterator i = listeners_.iterator(); i.hasNext();)
{
delegate_.removeDiscardListener((DiscardListener) i.next());
}
if (delegate_.hasPendingMessages())
{
final Message[] _allMessages = delegate_.getAllMessages();
for (int x = 0; x < _allMessages.length; ++x)
{
newDelegate.enqeue(_allMessages[x]);
}
}
delegate_ = newDelegate;
for (Iterator i = listeners_.iterator(); i.hasNext();)
{
delegate_.addDiscardListener((DiscardListener) i.next());
}
} finally
{
delegateLock_.writeLock().unlock();
}
}
public void enqeue(Message message) throws InterruptedException
{
delegateLock_.readLock().lock();
try
{
delegate_.enqeue(message);
} finally
{
delegateLock_.readLock().unlock();
}
}
public boolean hasPendingMessages() throws InterruptedException
{
delegateLock_.readLock().lock();
try
{
return delegate_.hasPendingMessages();
} finally
{
delegateLock_.readLock().unlock();
}
}
public int getPendingMessagesCount() throws InterruptedException
{
delegateLock_.readLock().lock();
try
{
return delegate_.getPendingMessagesCount();
} finally
{
delegateLock_.readLock().unlock();
}
}
public Message getMessageBlocking() throws InterruptedException
{
delegateLock_.readLock().lock();
try
{
return delegate_.getMessageBlocking();
} finally
{
delegateLock_.readLock().unlock();
}
}
public Message getMessageNoBlock() throws InterruptedException
{
delegateLock_.readLock().lock();
try
{
return delegate_.getMessageNoBlock();
} finally
{
delegateLock_.readLock().unlock();
}
}
public Message[] getAllMessages() throws InterruptedException
{
delegateLock_.readLock().lock();
try
{
return delegate_.getAllMessages();
} finally
{
delegateLock_.readLock().unlock();
}
}
public Message[] getUpToMessages(int max) throws InterruptedException
{
delegateLock_.readLock().lock();
try
{
return delegate_.getUpToMessages(max);
} finally
{
delegateLock_.readLock().unlock();
}
}
public Message[] getAtLeastMessages(int min) throws InterruptedException
{
delegateLock_.readLock().lock();
try
{
return delegate_.getAtLeastMessages(min);
} finally
{
delegateLock_.readLock().unlock();
}
}
public void clear()
{
delegateLock_.readLock().lock();
try
{
delegate_.clear();
} finally
{
delegateLock_.readLock().unlock();
}
}
public String toString()
{
lockReadLock();
try
{
return delegate_.toString();
} finally
{
delegateLock_.readLock().unlock();
}
}
private void lockReadLock()
{
delegateLock_.readLock().lock();
}
public String getDiscardPolicyName()
{
lockReadLock();
try
{
return delegate_.getDiscardPolicyName();
} finally
{
delegateLock_.readLock().unlock();
}
}
public String getOrderPolicyName()
{
lockReadLock();
try
{
return delegate_.getOrderPolicyName();
} finally
{
delegateLock_.readLock().unlock();
}
}
public void addDiscardListener(DiscardListener listener)
{
lockReadLock();
try
{
listeners_.add(listener);
delegate_.addDiscardListener(listener);
} finally
{
delegateLock_.readLock().unlock();
}
}
public void removeDiscardListener(DiscardListener listener)
{
lockReadLock();
try
{
listeners_.remove(listener);
delegate_.removeDiscardListener(listener);
} finally
{
delegateLock_.readLock().unlock();
}
}
}