/* 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.jobexecutor;
import java.util.Date;
import java.util.List;
import java.util.concurrent.atomic.AtomicBoolean;
import java.util.logging.Level;
import java.util.logging.Logger;
import org.activiti.engine.ActivitiOptimisticLockingException;
import org.activiti.engine.impl.Page;
import org.activiti.engine.impl.interceptor.CommandExecutor;
import org.activiti.engine.impl.persistence.entity.TimerEntity;
import org.activiti.engine.impl.util.ClockUtil;
/**
*
* @author Daniel Meyer
*/
public class AcquireJobsRunnable implements Runnable {
private static Logger log = Logger.getLogger(AcquireJobsRunnable.class.getName());
protected final JobExecutor jobExecutor;
protected volatile boolean isInterrupted = false;
protected volatile boolean isJobAdded = false;
protected final Object MONITOR = new Object();
protected final AtomicBoolean isWaiting = new AtomicBoolean(false);
protected long millisToWait = 0;
protected float waitIncreaseFactor = 2;
protected long maxWait = 60 * 1000;
public AcquireJobsRunnable(JobExecutor jobExecutor) {
this.jobExecutor = jobExecutor;
}
public synchronized void run() {
if (log.isLoggable(Level.INFO)) {
log.info(jobExecutor.getName() + " starting to acquire jobs");
}
final CommandExecutor commandExecutor = jobExecutor.getCommandExecutor();
while (!isInterrupted) {
int maxJobsPerAcquisition = jobExecutor.getMaxJobsPerAcquisition();
try {
AcquiredJobs acquiredJobs = commandExecutor.execute(jobExecutor.getAcquireJobsCmd());
for (List<String> jobIds : acquiredJobs.getJobIdBatches()) {
jobExecutor.executeJobs(jobIds);
}
// if all jobs were executed
millisToWait = jobExecutor.getWaitTimeInMillis();
int jobsAcquired = acquiredJobs.getJobIdBatches().size();
if (jobsAcquired < maxJobsPerAcquisition) {
isJobAdded = false;
// check if the next timer should fire before the normal sleep time is over
Date duedate = new Date(ClockUtil.getCurrentTime().getTime() + millisToWait);
List<TimerEntity> nextTimers = commandExecutor.execute(new GetUnlockedTimersByDuedateCmd(duedate, new Page(0, 1)));
if (!nextTimers.isEmpty()) {
long millisTillNextTimer = nextTimers.get(0).getDuedate().getTime() - ClockUtil.getCurrentTime().getTime();
if (millisTillNextTimer < millisToWait) {
millisToWait = millisTillNextTimer;
}
}
} else {
millisToWait = 0;
}
} catch (ActivitiOptimisticLockingException optimisticLockingException) {
// See http://jira.codehaus.org/browse/ACT-1390
if (log.isLoggable(Level.FINE)) {
log.fine("Optimistic locking exception during job acquisition. If you have multiple job executors running against the same database, " +
"this exception means that this thread tried to acquire a job, which already was acquired by another job executor acquisition 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 (Exception e) {
if (log.isLoggable(Level.SEVERE)) {
log.log(Level.SEVERE, "exception during job acquisition: " + e.getMessage(), e);
}
millisToWait *= waitIncreaseFactor;
if (millisToWait > maxWait) {
millisToWait = maxWait;
} else if (millisToWait==0) {
millisToWait = jobExecutor.getWaitTimeInMillis();
}
}
if ((millisToWait > 0) && (!isJobAdded)) {
try {
if (log.isLoggable(Level.FINE)) {
log.fine("job acquisition thread sleeping for " + millisToWait + " millis");
}
synchronized (MONITOR) {
if(!isInterrupted) {
isWaiting.set(true);
MONITOR.wait(millisToWait);
}
}
if (log.isLoggable(Level.FINE)) {
log.fine("job acquisition thread woke up");
}
} catch (InterruptedException e) {
if (log.isLoggable(Level.FINE)) {
log.fine("job acquisition wait interrupted");
}
} finally {
isWaiting.set(false);
}
}
}
if (log.isLoggable(Level.INFO)) {
log.info(jobExecutor.getName() + " stopped job acquisition");
}
}
public void stop() {
synchronized (MONITOR) {
isInterrupted = true;
if(isWaiting.compareAndSet(true, false)) {
MONITOR.notifyAll();
}
}
}
public void jobWasAdded() {
isJobAdded = true;
if(isWaiting.compareAndSet(true, false)) {
// ensures we only notify once
// I am OK with the race condition
synchronized (MONITOR) {
MONITOR.notifyAll();
}
}
}
public long getMillisToWait() {
return millisToWait;
}
public void setMillisToWait(long millisToWait) {
this.millisToWait = millisToWait;
}
public float getWaitIncreaseFactor() {
return waitIncreaseFactor;
}
public void setWaitIncreaseFactor(float waitIncreaseFactor) {
this.waitIncreaseFactor = waitIncreaseFactor;
}
public long getMaxWait() {
return maxWait;
}
public void setMaxWait(long maxWait) {
this.maxWait = maxWait;
}
}