bitronix.tm.resource.common.AbstractXAResourceHolder Maven / Gradle / Ivy
/*
* Copyright (C) 2006-2013 Bitronix Software (http://www.bitronix.be)
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package bitronix.tm.resource.common;
import bitronix.tm.BitronixTransaction;
import bitronix.tm.BitronixXid;
import bitronix.tm.internal.LogDebugCheck;
import bitronix.tm.internal.XAResourceHolderState;
import bitronix.tm.utils.Uid;
import java.util.*;
import java.util.concurrent.locks.ReentrantReadWriteLock;
/**
* Implementation of all services required by a {@link XAResourceHolder}. This class keeps a list of all
* {@link XAResourceHolderState}s of the {@link XAResourceHolder} plus the currently active one. There is
* one per transaction in which this {@link XAResourceHolder} is enlisted plus all the suspended transactions in which
* it is enlisted as well.
*
* @author Ludovic Orban
*/
public abstract class AbstractXAResourceHolder>
extends AbstractXAStatefulHolder
implements XAResourceHolder
{
private static final java.util.logging.Logger log = java.util.logging.Logger.getLogger(AbstractXAResourceHolder.class.toString());
private final Map> xaResourceHolderStates = new HashMap<>();
private final ReentrantReadWriteLock rwLock = new ReentrantReadWriteLock();
/**
* Method getXAResourceHolderStatesForGtrid ...
*
* @param gtrid
* of type Uid
*
* @return Map Uid XAResourceHolderState
*/
// This method is only used by tests. It is (and always was) potentially thread-unsafe depending on what callers do with the returned map.
protected Map getXAResourceHolderStatesForGtrid(Uid gtrid)
{
rwLock.readLock()
.lock();
try
{
return xaResourceHolderStates.get(gtrid);
}
finally
{
rwLock.readLock()
.unlock();
}
}
/**
* This method implements a standard Visitor Pattern. For the specified GTRID, the
* provided {@link bitronix.tm.resource.common.XAResourceHolderStateVisitor}'s visit() method is called for each matching
* {@link bitronix.tm.internal.XAResourceHolderState} in the order they were added. This method was introduced
* as a replacement for the old getXAResourceHolderStatesForGtrid(Uid) method. The old
* getXAResourceHolderStatesForGtrid method exported an internal collection which was unsynchronized
* yet was iterated over by the callers. Using the Visitor Pattern allows us to perform the same
* iteration within the context of a lock, and avoids exposing internal state and implementation
* details to callers.
*
* @param gtrid
* the GTRID of the transaction state to visit {@link bitronix.tm.internal.XAResourceHolderState}s for
* @param visitor
* a {@link bitronix.tm.resource.common.XAResourceHolderStateVisitor} instance
*/
@Override
public void acceptVisitorForXAResourceHolderStates(Uid gtrid, XAResourceHolderStateVisitor visitor)
{
rwLock.readLock()
.lock();
try
{
Map statesForGtrid = xaResourceHolderStates.get(gtrid);
if (statesForGtrid != null)
{
for (XAResourceHolderState xaResourceHolderState : statesForGtrid.values())
{
visitor.visit(xaResourceHolderState);
}
}
}
finally
{
rwLock.readLock()
.unlock();
}
}
/**
* Checks whether there are {@link bitronix.tm.internal.XAResourceHolderState}s for the specified GTRID.
*
* @param gtrid
* the GTRID of the transaction state to check existence for
*
* @return true if there are {@link bitronix.tm.internal.XAResourceHolderState}s, false otherwise
*/
@Override
public boolean isExistXAResourceHolderStatesForGtrid(Uid gtrid)
{
rwLock.readLock()
.lock();
try
{
return xaResourceHolderStates.containsKey(gtrid);
}
finally
{
rwLock.readLock()
.unlock();
}
}
/**
* Get a count of {@link bitronix.tm.internal.XAResourceHolderState}s for the specified GTRID.
*
* @param gtrid
* the GTRID to get a {@link bitronix.tm.internal.XAResourceHolderState} count for
*
* @return the count of {@link bitronix.tm.internal.XAResourceHolderState}s, or 0 if there are no states for the
* specified GTRID
*/
@Override
public int getXAResourceHolderStateCountForGtrid(Uid gtrid)
{
rwLock.readLock()
.lock();
try
{
Map statesForGtrid = xaResourceHolderStates.get(gtrid);
if (statesForGtrid != null)
{
return statesForGtrid.size();
}
return 0;
}
finally
{
rwLock.readLock()
.unlock();
}
}
/**
* Add a {@link bitronix.tm.internal.XAResourceHolderState} of this wrapped resource.
*
* @param xid
* the Xid of the transaction state to add.
* @param xaResourceHolderState
* the {@link bitronix.tm.internal.XAResourceHolderState} to set.
*/
@Override
public void putXAResourceHolderState(BitronixXid xid, XAResourceHolderState xaResourceHolderState)
{
Uid gtrid = xid.getGlobalTransactionIdUid();
Uid bqual = xid.getBranchQualifierUid();
rwLock.writeLock()
.lock();
try
{
if (LogDebugCheck.isDebugEnabled())
{
log.finer("putting XAResourceHolderState [" + xaResourceHolderState + "] on " + this);
}
if (!xaResourceHolderStates.containsKey(gtrid))
{
if (LogDebugCheck.isDebugEnabled())
{
log.finer("GTRID [" + gtrid + "] previously unknown to " + this + ", adding it to the resource's transactions list");
}
// use a LinkedHashMap as iteration order must be guaranteed
Map statesForGtrid = new LinkedHashMap<>(4);
statesForGtrid.put(bqual, xaResourceHolderState);
xaResourceHolderStates.put(gtrid, statesForGtrid);
}
else
{
if (LogDebugCheck.isDebugEnabled())
{
log.finer("GTRID [" + gtrid + "] previously known to " + this + ", adding it to the resource's transactions list");
}
Map statesForGtrid = xaResourceHolderStates.get(gtrid);
statesForGtrid.put(bqual, xaResourceHolderState);
}
}
finally
{
rwLock.writeLock()
.unlock();
}
}
/**
* Remove all states related to a specific Xid from this wrapped resource.
*
* @param xid
* the Xid of the transaction state to remove.
*/
@Override
public void removeXAResourceHolderState(BitronixXid xid)
{
Uid gtrid = xid.getGlobalTransactionIdUid();
Uid bqual = xid.getBranchQualifierUid();
rwLock.writeLock()
.lock();
try
{
if (LogDebugCheck.isDebugEnabled())
{
log.finer("removing XAResourceHolderState of xid " + xid + " from " + this);
}
Map statesForGtrid = xaResourceHolderStates.get(gtrid);
if (statesForGtrid == null)
{
log.warning("tried to remove unknown GTRID [" + gtrid + "] from " + this + " - Bug?");
return;
}
XAResourceHolderState removed = statesForGtrid.remove(bqual);
if (removed == null)
{
log.warning("tried to remove unknown BQUAL [" + bqual + "] from " + this + " - Bug?");
return;
}
if (statesForGtrid.isEmpty())
{
xaResourceHolderStates.remove(gtrid);
}
}
finally
{
rwLock.writeLock()
.unlock();
}
}
/**
* Check if this {@link bitronix.tm.resource.common.XAResourceHolder} contains a state for a specific {@link bitronix.tm.resource.common.XAResourceHolder}.
* In other words: has the {@link bitronix.tm.resource.common.XAResourceHolder}'s {@link javax.transaction.xa.XAResource} been enlisted in some transaction ?
*
* @param xaResourceHolder
* the {@link bitronix.tm.resource.common.XAResourceHolder} to look for.
*
* @return true if the {@link bitronix.tm.resource.common.XAResourceHolder} is enlisted in some transaction, false otherwise.
*/
@Override
public boolean hasStateForXAResource(XAResourceHolder xaResourceHolder)
{
rwLock.readLock()
.lock();
try
{
for (Map statesForGtrid : xaResourceHolderStates.values())
{
for (XAResourceHolderState otherXaResourceHolderState : statesForGtrid.values())
{
if (otherXaResourceHolderState.getXAResource() == xaResourceHolder.getXAResource())
{
if (LogDebugCheck.isDebugEnabled())
{
log.finer("resource " + xaResourceHolder + " is enlisted in another transaction with " + otherXaResourceHolderState.getXid()
.toString());
}
return true;
}
}
}
if (LogDebugCheck.isDebugEnabled())
{
log.finer("resource not enlisted in any transaction: " + xaResourceHolder);
}
return false;
}
finally
{
rwLock.readLock()
.unlock();
}
}
/**
* If this method returns false, then local transaction calls like Connection.commit() can be made.
*
* @return true if start() has been successfully called but not end() yet and the transaction is not suspended.
*/
public boolean isParticipatingInActiveGlobalTransaction()
{
rwLock.readLock()
.lock();
try
{
BitronixTransaction currentTransaction = TransactionContextHelper.currentTransaction();
Uid gtrid = currentTransaction == null
? null
: currentTransaction.getResourceManager()
.getGtrid();
if (gtrid == null)
{
return false;
}
Map statesForGtrid = xaResourceHolderStates.get(gtrid);
if (statesForGtrid == null)
{
return false;
}
for (XAResourceHolderState xaResourceHolderState : statesForGtrid.values())
{
if (xaResourceHolderState != null &&
xaResourceHolderState.isStarted() &&
!xaResourceHolderState.isSuspended() &&
!xaResourceHolderState.isEnded())
{
return true;
}
}
return false;
}
finally
{
rwLock.readLock()
.unlock();
}
}
/**
* Simple helper method which returns a set of GTRIDs of transactions in which
* this resource is enlisted. Useful for monitoring.
*
* @return a set of String-encoded GTRIDs of transactions in which this resource is enlisted.
*/
public Set getXAResourceHolderStateGtrids()
{
rwLock.readLock()
.lock();
try
{
HashSet gtridsAsStrings = new HashSet<>();
for (Uid uid : xaResourceHolderStates.keySet())
{
gtridsAsStrings.add(uid.toString());
}
return gtridsAsStrings;
}
finally
{
rwLock.readLock()
.unlock();
}
}
}