/* 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 org.activiti.engine.impl.asyncexecutor;
import org.activiti.engine.ActivitiOptimisticLockingException;
import org.activiti.engine.delegate.event.ActivitiEventType;
import org.activiti.engine.delegate.event.impl.ActivitiEventBuilder;
import org.activiti.engine.impl.cmd.ExecuteAsyncJobCmd;
import org.activiti.engine.impl.cmd.LockExclusiveJobCmd;
import org.activiti.engine.impl.cmd.UnlockExclusiveJobCmd;
import org.activiti.engine.impl.context.Context;
import org.activiti.engine.impl.interceptor.Command;
import org.activiti.engine.impl.interceptor.CommandConfig;
import org.activiti.engine.impl.interceptor.CommandContext;
import org.activiti.engine.impl.interceptor.CommandExecutor;
import org.activiti.engine.impl.jobexecutor.FailedJobCommandFactory;
import org.activiti.engine.impl.persistence.entity.JobEntity;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* @author Joram Barrez
* @author Tijs Rademakers
*/
public class ExecuteAsyncRunnable implements Runnable {
private static Logger log = LoggerFactory.getLogger(ExecuteAsyncRunnable.class);
protected JobEntity job;
protected CommandExecutor commandExecutor;
public ExecuteAsyncRunnable(JobEntity job, CommandExecutor commandExecutor) {
this.job = job;
this.commandExecutor = commandExecutor;
}
public void run() {
boolean lockNotNeededOrSuccess = lockJobIfNeeded();
if (lockNotNeededOrSuccess) {
executeJob();
unlockJobIfNeeded();
}
}
/**
* Returns true if lock succeeded, or no lock was needed.
* Returns false if locking was unsuccessfull.
*/
protected boolean lockJobIfNeeded() {
try {
if (job.isExclusive()) {
commandExecutor.execute(new LockExclusiveJobCmd(job));
}
} catch (Throwable lockException) {
if (log.isDebugEnabled()) {
log.debug("Could not lock exclusive job. Unlocking job so it can be acquired again. Catched exception: " + lockException.getMessage());
}
// Release the job again so it can be acquired later or by another node
unacquireJob();
return false;
}
return true;
}
protected void unacquireJob() {
CommandContext commandContext = Context.getCommandContext();
if (commandContext != null) {
commandContext.getJobEntityManager().unacquireJob(job.getId());
} else {
commandExecutor.execute(new Command<Void>() {
public Void execute(CommandContext commandContext) {
commandContext.getJobEntityManager().unacquireJob(job.getId());
return null;
}
});
}
}
protected void executeJob() {
try {
commandExecutor.execute(new ExecuteAsyncJobCmd(job));
} catch (final ActivitiOptimisticLockingException e) {
handleFailedJob(e);
if (log.isDebugEnabled()) {
log.debug("Optimistic locking exception during job execution. If you have multiple async executors running against the same database, " +
"this exception means that this thread tried to acquire an exclusive job, which already was changed by another async executor thread." +
"This is expected behavior in a clustered environment. " +
"You can ignore this message if you indeed have multiple job executor threads running against the same database. " +
"Exception message: {}", e.getMessage());
}
} catch (Throwable exception) {
handleFailedJob(exception);
// Finally, Throw the exception to indicate the ExecuteAsyncJobCmd failed
String message = "Job " + job.getId() + " failed";
log.error(message, exception);
}
}
protected void unlockJobIfNeeded() {
try {
if (job.isExclusive()) {
commandExecutor.execute(new UnlockExclusiveJobCmd(job));
}
} catch (ActivitiOptimisticLockingException optimisticLockingException) {
if (log.isDebugEnabled()) {
log.debug("Optimistic locking exception while unlocking the job. If you have multiple async executors running against the same database, " +
"this exception means that this thread tried to acquire an exclusive job, which already was changed by another async executor thread." +
"This is expected behavior in a clustered environment. " +
"You can ignore this message if you indeed have multiple job executor acquisition threads running against the same database. " +
"Exception message: {}", optimisticLockingException.getMessage());
}
} catch (Throwable t) {
log.error("Error while unlocking exclusive job " + job.getId(), t);
}
}
protected void handleFailedJob(final Throwable exception) {
commandExecutor.execute(new Command<Void>() {
@Override
public Void execute(CommandContext commandContext) {
CommandConfig commandConfig = commandExecutor.getDefaultConfig().transactionRequiresNew();
FailedJobCommandFactory failedJobCommandFactory = commandContext.getFailedJobCommandFactory();
Command<Object> cmd = failedJobCommandFactory.getCommand(job.getId(), exception);
log.trace("Using FailedJobCommandFactory '" + failedJobCommandFactory.getClass() + "' and command of type '" + cmd.getClass() + "'");
commandExecutor.execute(commandConfig, cmd);
// Dispatch an event, indicating job execution failed in a try-catch block, to prevent the original
// exception to be swallowed
if (commandContext.getEventDispatcher().isEnabled()) {
try {
commandContext.getEventDispatcher().dispatchEvent(ActivitiEventBuilder.createEntityExceptionEvent(
ActivitiEventType.JOB_EXECUTION_FAILURE, job, exception));
} catch(Throwable ignore) {
log.warn("Exception occured while dispatching job failure event, ignoring.", ignore);
}
}
return null;
}
});
}
}