/* 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 org.activiti.crystalball.simulator.SimulationEvent;
import org.activiti.crystalball.simulator.SimulationRunContext;
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.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* "thread" has to be driven by simulation time.
* In fact new thread is not started. Simulation is driven by simulation time.
* In case of thread for acquiring jobs, synchronization will be over complicated.
*
* @author martin.grofcik
*/
public class SimulationAcquireJobsRunnable extends AcquireJobsRunnableImpl {
private static Logger log = LoggerFactory.getLogger(SimulationAcquireJobsRunnable.class.getName());
public SimulationAcquireJobsRunnable(JobExecutor jobExecutor) {
super(jobExecutor);
}
public synchronized void run() {
// if (log.isLoggable(Level.INFO)) {
// log.info(jobExecutor.getName() + " starting to acquire jobs");
// }
final CommandExecutor commandExecutor = jobExecutor.getCommandExecutor();
// while is not needed - repetition is done by event scheduling
// while (!isInterrupted) {
isWaiting.set(false);
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(SimulationRunContext.getClock().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() - SimulationRunContext.getClock().getCurrentTime().getTime();
if (millisTillNextTimer < millisToWait && millisTillNextTimer != 0) {
millisToWait = millisTillNextTimer;
}
}
} else {
millisToWait = 0;
}
} catch (ActivitiOptimisticLockingException optimisticLockingException) {
// See https://activiti.atlassian.net/browse/ACT-1390
log.trace("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) {
log.error("exception during job acquisition: " + e.getMessage(), e);
millisToWait = jobExecutor.getWaitTimeInMillis();
}
if ((millisToWait > 0) && (!isJobAdded)) {
try {
log.trace("job acquisition thread sleeping for " + millisToWait + " millis");
synchronized (MONITOR) {
if(!isInterrupted) {
isWaiting.set(true);
SimulationEvent event = new SimulationEvent.Builder(SimulationEvent.TYPE_ACQUIRE_JOB_NOTIFICATION_EVENT).
simulationTime(SimulationRunContext.getClock().getCurrentTime().getTime() + millisToWait).
property(this).
build();
SimulationRunContext.getEventCalendar().addEvent(event);
// do not need to wait. - event scheduling is enough
//MONITOR.wait(millisToWait);
}
}
log.trace("job acquisition thread woke up");
} finally {
// isWaiting.set(false);
}
} else {
// schedule run now
SimulationEvent event = new SimulationEvent.Builder(SimulationEvent.TYPE_ACQUIRE_JOB_NOTIFICATION_EVENT).
simulationTime(SimulationRunContext.getClock().getCurrentTime().getTime()).
property(this).
build();
SimulationRunContext.getEventCalendar().addEvent(event);
}
// }
// if (log.isLoggable(Level.INFO)) {
// log.info(jobExecutor.getName() + " stopped job acquisition");
// }
}
public void stop() {
synchronized (MONITOR) {
isInterrupted = true;
// if(isWaiting.compareAndSet(true, false)) {
// Notify is not needed - event is enough
// SimulationContext.getEventCalendar().addEvent( new SimulationEvent(
// ClockUtil.getCurrentTime().getTime(),
// SimulationEvent.TYPE_ACQUIRE_JOB_NOTIFICATION_EVENT,
// this) );
//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();
//Notify is not needed - event is enough
SimulationEvent event = new SimulationEvent.Builder(SimulationEvent.TYPE_ACQUIRE_JOB_NOTIFICATION_EVENT).
simulationTime(SimulationRunContext.getClock().getCurrentTime().getTime()).
property(this).
build();
SimulationRunContext.getEventCalendar().addEvent(event);
}
}
}
}