/*
* 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.twopc;
import bitronix.tm.BitronixTransaction;
import bitronix.tm.TransactionManagerServices;
import bitronix.tm.internal.BitronixRollbackException;
import bitronix.tm.internal.BitronixSystemException;
import bitronix.tm.internal.XAResourceHolderState;
import bitronix.tm.internal.XAResourceManager;
import bitronix.tm.twopc.executor.Executor;
import bitronix.tm.twopc.executor.Job;
import bitronix.tm.utils.Decoder;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import javax.transaction.RollbackException;
import javax.transaction.Status;
import javax.transaction.xa.XAException;
import javax.transaction.xa.XAResource;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
/**
* Phase 1 Prepare logic engine.
*
* @author Ludovic Orban
*/
public final class Preparer extends AbstractPhaseEngine {
private final static Logger log = LoggerFactory.getLogger(Preparer.class);
// this list has to be thread-safe as the PrepareJobs can be executed in parallel (when async 2PC is configured)
private final List<XAResourceHolderState> preparedResources = Collections.synchronizedList(new ArrayList<XAResourceHolderState>());
public Preparer(Executor executor) {
super(executor);
}
/**
* Execute phase 1 prepare.
* @param transaction the transaction to prepare.
* @return a list that will be filled with all resources that received the prepare command
* and replied with {@link javax.transaction.xa.XAResource#XA_OK}.
* @throws RollbackException when an error occured that can be fixed with a rollback.
* @throws bitronix.tm.internal.BitronixSystemException when an internal error occured.
*/
public List<XAResourceHolderState> prepare(BitronixTransaction transaction) throws RollbackException, BitronixSystemException {
XAResourceManager resourceManager = transaction.getResourceManager();
transaction.setStatus(Status.STATUS_PREPARING);
preparedResources.clear();
if (resourceManager.size() == 0) {
if (TransactionManagerServices.getConfiguration().isWarnAboutZeroResourceTransaction())
log.warn("executing transaction with 0 enlisted resource");
else
if (log.isDebugEnabled()) { log.debug("0 resource enlisted, no prepare needed"); }
transaction.setStatus(Status.STATUS_PREPARED);
return preparedResources;
}
// 1PC optimization
if (resourceManager.size() == 1) {
XAResourceHolderState resourceHolder = resourceManager.getAllResources().get(0);
preparedResources.add(resourceHolder);
if (log.isDebugEnabled()) { log.debug("1 resource enlisted, no prepare needed (1PC)"); }
transaction.setStatus(Status.STATUS_PREPARED);
return preparedResources;
}
try {
executePhase(resourceManager, false);
} catch (PhaseException ex) {
logFailedResources(ex);
throwException("transaction failed during prepare of " + transaction, ex);
}
transaction.setStatus(Status.STATUS_PREPARED);
if (log.isDebugEnabled()) { log.debug("successfully prepared " + preparedResources.size() + " resource(s)"); }
return Collections.unmodifiableList(preparedResources);
}
private void throwException(String message, PhaseException phaseException) throws BitronixRollbackException {
List<Exception> exceptions = phaseException.getExceptions();
List<XAResourceHolderState> resources = phaseException.getResourceStates();
List<XAResourceHolderState> heuristicResources = new ArrayList<XAResourceHolderState>();
List<XAResourceHolderState> errorResources = new ArrayList<XAResourceHolderState>();
for (int i = 0; i < exceptions.size(); i++) {
Exception ex = exceptions.get(i);
XAResourceHolderState resourceHolder = resources.get(i);
if (ex instanceof XAException) {
XAException xaEx = (XAException) ex;
/**
* Sybase ASE can sometimes forget a transaction before prepare. For instance, when executing
* a stored procedure that contains a rollback statement. In that case it throws XAException(XAER_NOTA)
* when asked to prepare.
*/
if (xaEx.errorCode == XAException.XAER_NOTA)
heuristicResources.add(resourceHolder);
else
errorResources.add(resourceHolder);
}
else
errorResources.add(resourceHolder);
}
if (heuristicResources.size() > 0)
throw new BitronixRollbackException(message + ":" +
" resource(s) " + Decoder.collectResourcesNames(heuristicResources) +
" unilaterally finished transaction branch before being asked to prepare", phaseException);
else
throw new BitronixRollbackException(message + ":" +
" resource(s) " + Decoder.collectResourcesNames(errorResources) +
" threw unexpected exception", phaseException);
}
protected Job createJob(XAResourceHolderState xaResourceHolderState) {
return new PrepareJob(xaResourceHolderState);
}
protected boolean isParticipating(XAResourceHolderState xaResourceHolderState) {
return true;
}
private final class PrepareJob extends Job {
public PrepareJob(XAResourceHolderState resourceHolder) {
super(resourceHolder);
}
public void execute() {
try {
XAResourceHolderState resourceHolder = getResource();
if (log.isDebugEnabled()) { log.debug("preparing resource " + resourceHolder); }
int vote = resourceHolder.getXAResource().prepare(resourceHolder.getXid());
if (vote != XAResource.XA_RDONLY) {
preparedResources.add(resourceHolder);
}
if (log.isDebugEnabled()) { log.debug("prepared resource " + resourceHolder + " voted " + Decoder.decodePrepareVote(vote)); }
} catch (RuntimeException ex) {
runtimeException = ex;
} catch (XAException ex) {
xaException = ex;
}
}
public String toString() {
return "a PrepareJob with " + getResource();
}
}
}