/*
* Copyright (c) 1998-2009 Caucho Technology -- all rights reserved
*
* This file is part of Resin(R) Open Source
*
* Each copy or derived work must preserve the copyright notice and this
* notice unmodified.
*
* Resin Open Source is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* Resin Open Source 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, or any warranty
* of NON-INFRINGEMENT. See the GNU General Public License for more
* details.
*
* You should have received a copy of the GNU General Public License
* along with Resin Open Source; if not, write to the
*
* Free Software Foundation, Inc.
* 59 Temple Place, Suite 330
* Boston, MA 02111-1307 USA
*
* @author Scott Ferguson
*/
package com.caucho.cluster;
import com.caucho.config.ConfigException;
import com.caucho.config.Configurable;
import com.caucho.inject.Module;
import com.caucho.loader.Environment;
import com.caucho.server.cluster.Server;
import com.caucho.server.distlock.AbstractLockManager;
import com.caucho.util.L10N;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.locks.Condition;
import java.util.concurrent.locks.Lock;
import javax.annotation.PostConstruct;
/**
* Implements the distributed lock
*/
@Module
abstract public class AbstractLock implements Lock
{
private static final L10N L = new L10N(AbstractLock.class);
private AbstractLockManager _manager;
private Lock _lock;
private String _name;
private String _guid;
private boolean _isInit;
/**
* Returns the name of the lock.
*/
public String getName()
{
return _name;
}
/**
* Assigns the name of the lock.
* A name is mandatory and must be unique among open locks.
*/
@Configurable
public void setName(String name)
{
_name = name;
}
public void setGuid(String guid)
{
_guid = guid;
}
//
// Lock API
//
@Override
public void lock()
{
_lock.lock();
}
@Override
public void lockInterruptibly()
throws InterruptedException
{
_lock.lockInterruptibly();
}
@Override
public boolean tryLock()
{
return _lock.tryLock();
}
@Override
public boolean tryLock(long time, TimeUnit unit)
throws InterruptedException
{
return _lock.tryLock(time, unit);
}
@Override
public void unlock()
{
_lock.unlock();
}
@Override
public Condition newCondition()
{
return _lock.newCondition();
}
/**
* Initialize the lock.
*/
@PostConstruct
public void init()
{
synchronized (this) {
if (_isInit)
return;
_isInit = true;
initServer();
initName(_name);
_lock = _manager.getOrCreateLock(_guid);
assert(_lock != null);
}
}
private void initName(String name)
throws ConfigException
{
if (_name == null || _name.length() == 0)
throw new ConfigException(L.l("'{0}' requires a name because each lock must be identified uniquely.", getClass().getSimpleName()));
// HashSet<String> cacheNameSet = getLocalCacheNameSet();
String contextId = Environment.getEnvironmentName();
if (_guid == null)
_guid = contextId + ":" + _name;
/*
_config.setGuid(_guid);
if (! cacheNameSet.contains(_guid))
cacheNameSet.add(_guid);
else
throw new ConfigException(L.l(
"'{0}' is an invalid Cache name because it's already used by another cache.",
_name));
*/
}
private void initServer()
throws ConfigException
{
Server server = Server.getCurrent();
if (server == null)
throw new ConfigException(L.l("'{0}' cannot be initialized because it is not in a Resin environment",
getClass().getSimpleName()));
_manager = server.getDistributedLockManager();
if (_manager == null)
throw new IllegalStateException("distributed lock manager not available");
}
@Override
public String toString()
{
return getClass().getSimpleName() + "[" + _guid + "]";
}
}