/* 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.camunda.bpm.engine.impl.cmd;
import java.util.ArrayList;
import java.util.Calendar;
import java.util.GregorianCalendar;
import java.util.List;
import org.camunda.bpm.engine.impl.Page;
import org.camunda.bpm.engine.impl.context.Context;
import org.camunda.bpm.engine.impl.db.DbEntity;
import org.camunda.bpm.engine.impl.db.entitymanager.OptimisticLockingListener;
import org.camunda.bpm.engine.impl.db.entitymanager.operation.DbEntityOperation;
import org.camunda.bpm.engine.impl.db.entitymanager.operation.DbOperation;
import org.camunda.bpm.engine.impl.interceptor.Command;
import org.camunda.bpm.engine.impl.interceptor.CommandContext;
import org.camunda.bpm.engine.impl.jobexecutor.AcquiredJobs;
import org.camunda.bpm.engine.impl.jobexecutor.JobExecutor;
import org.camunda.bpm.engine.impl.persistence.entity.JobEntity;
import org.camunda.bpm.engine.impl.util.ClockUtil;
/**
* @author Nick Burch
* @author Daniel Meyer
*/
public class AcquireJobsCmd implements Command<AcquiredJobs>, OptimisticLockingListener {
private final JobExecutor jobExecutor;
protected AcquiredJobs acquiredJobs;
public AcquireJobsCmd(JobExecutor jobExecutor) {
this.jobExecutor = jobExecutor;
}
public AcquiredJobs execute(CommandContext commandContext) {
String lockOwner = jobExecutor.getLockOwner();
int lockTimeInMillis = jobExecutor.getLockTimeInMillis();
int maxNonExclusiveJobsPerAcquisition = jobExecutor.getMaxJobsPerAcquisition();
acquiredJobs = new AcquiredJobs();
List<JobEntity> jobs = commandContext
.getJobManager()
.findNextJobsToExecute(new Page(0, maxNonExclusiveJobsPerAcquisition));
for (JobEntity job: jobs) {
List<String> jobIds = new ArrayList<String>();
if (job != null && !acquiredJobs.contains(job.getId())) {
if (job.isExclusive() && job.getProcessInstanceId() != null) {
// acquire all exclusive jobs in the same process instance
// (includes the current job)
List<JobEntity> exclusiveJobs = commandContext.getJobManager()
.findExclusiveJobsToExecute(job.getProcessInstanceId());
for (JobEntity exclusiveJob : exclusiveJobs) {
if(exclusiveJob != null) {
lockJob(exclusiveJob, lockOwner, lockTimeInMillis);
jobIds.add(exclusiveJob.getId());
}
}
} else {
lockJob(job, lockOwner, lockTimeInMillis);
jobIds.add(job.getId());
}
}
acquiredJobs.addJobIdBatch(jobIds);
}
// register an OptimisticLockingListener which is notified about jobs which cannot be acquired.
// the listener removes them from the list of acquired jobs.
Context.getCommandContext()
.getDbEntityManager()
.registerOptimisticLockingListener(this);
return acquiredJobs;
}
protected void lockJob(JobEntity job, String lockOwner, int lockTimeInMillis) {
job.setLockOwner(lockOwner);
GregorianCalendar gregorianCalendar = new GregorianCalendar();
gregorianCalendar.setTime(ClockUtil.getCurrentTime());
gregorianCalendar.add(Calendar.MILLISECOND, lockTimeInMillis);
job.setLockExpirationTime(gregorianCalendar.getTime());
}
public Class<? extends DbEntity> getEntityType() {
return JobEntity.class;
}
public void failedOperation(DbOperation operation) {
if (operation instanceof DbEntityOperation) {
DbEntityOperation entityOperation = (DbEntityOperation) operation;
if(JobEntity.class.isAssignableFrom(entityOperation.getEntityType())) {
// could not lock the job -> remove it from list of acquired jobs
acquiredJobs.removeJobId(entityOperation.getEntity().getId());
}
}
}
}