/*
* JBoss, Home of Professional Open Source
* Copyright 2005, JBoss Inc., and individual contributors as indicated
* by the @authors tag. See the copyright.txt 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.jbpm.pvm.internal.svc;
import org.jbpm.api.JbpmException;
import org.jbpm.internal.log.Log;
import org.jbpm.pvm.internal.cmd.Command;
import org.hibernate.StaleStateException;
/** retries the command execution in case hibernate throws optimistic locking
* (StaleObjectException) exceptions.
*
* @author Tom Baeyens
*/
public class RetryInterceptor extends Interceptor {
private static final Log log = Log.getLog(RetryInterceptor.class.getName());
int retries = 3;
long delay = 50;
long delayFactor = 4;
public <T> T execute(Command<T> command) {
// TODO JBPM-2196 unify the retry code with the JtaTransactionInterceptor
int attempt = 1;
long sleepTime = delay;
while (attempt<=retries) {
if (attempt>1) {
log.trace("retrying...");
}
try {
return next.execute(command);
} catch (StaleStateException e) {
attempt++;
log.trace("optimistic locking failed: "+e);
log.trace("waiting "+sleepTime+" millis");
try {
Thread.sleep(sleepTime);
} catch (InterruptedException e1) {
log.trace("retry sleeping got interrupted");
}
sleepTime *= delayFactor;
}
}
throw new JbpmException("gave up after "+attempt+" attempts");
}
public int getRetries() {
return retries;
}
public void setRetries(int retries) {
this.retries = retries;
}
public long getDelay() {
return delay;
}
public void setDelay(long delay) {
this.delay = delay;
}
public long getDelayFactor() {
return delayFactor;
}
public void setDelayFactor(long delayFactor) {
this.delayFactor = delayFactor;
}
}