/*
* JBoss, Home of Professional Open Source.
* Copyright 2009, Red Hat Middleware LLC, and individual contributors
* as indicated by the @author tags. See the copyright.txt file in the
* distribution for a full listing of individual contributors.
*
* This is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation; either version 2.1 of
* the License, or (at your option) any later version.
*
* This software 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this software; if not, write to the Free
* Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA, or see the FSF site: http://www.fsf.org.
*/
package org.jboss.ha.framework.server.lock;
import java.io.Serializable;
import org.jboss.ha.framework.interfaces.ClusterNode;
import org.jboss.ha.framework.interfaces.HAPartition;
/**
* Support class for cluster locking scenarios where threads can hold a
* local lock on a category but not a cluster-wide lock. Multiple nodes can
* simultaneously hold a local lock on a category, but none can hold a local
* lock on a category if the cluster-wide lock is held. Cluster-wide lock cannot
* be acquired while any node holds a local lock.
* <p>
* <strong>NOTE:</strong> This class does not support "upgrades", i.e. scenarios
* where a thread acquires the local lock and then while holding the local
* lock attempts to acquire the cluster-wide lock.
* </p>
*
* @author Brian Stansberry
*/
public class NonGloballyExclusiveClusterLockSupport extends AbstractClusterLockSupport
{
// ------------------------------------------------------------- Constructor
public NonGloballyExclusiveClusterLockSupport(String serviceHAName,
HAPartition partition,
LocalLockHandler handler)
{
super(serviceHAName, partition, handler);
}
// ------------------------------------------------------------------ Public
public void unlock(Serializable lockId)
{
ClusterNode myself = getLocalClusterNode();
if (myself == null)
{
throw new IllegalStateException("Must call start() before first call to unlock()");
}
ClusterLockState lockState = getClusterLockState(lockId, false);
if (lockState != null && myself.equals(lockState.getHolder()))
{
getLocalHandler().unlockFromCluster(lockId, myself);
lockState.release();
try
{
getPartition().callMethodOnCluster(getServiceHAName(), "releaseRemoteLock",
new Object[]{lockId, myself},
RELEASE_REMOTE_LOCK_TYPES, true);
}
catch (RuntimeException e)
{
throw e;
}
catch (Exception e)
{
throw new RuntimeException("Failed releasing remote lock", e);
}
}
}
// --------------------------------------------------------------- Protected
@Override
protected ClusterLockState getClusterLockState(Serializable categoryName)
{
return getClusterLockState(categoryName, true);
}
@Override
protected RemoteLockResponse yieldLock(ClusterLockState lockState, ClusterNode caller, long timeout)
{
return new RemoteLockResponse(getLocalClusterNode(), RemoteLockResponse.Flag.REJECT, lockState.getHolder());
}
@Override
protected RemoteLockResponse handleLockSuccess(ClusterLockState lockState, ClusterNode caller)
{
recordLockHolder(lockState, caller);
return new RemoteLockResponse(getLocalClusterNode(), RemoteLockResponse.Flag.OK);
}
// ----------------------------------------------------------------- Private
}