content: /*
   * Copyright 2010-2025 Hyland Software, Inc. and its affiliates.
   *
   * 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 java.util.concurrent.atomic.AtomicBoolean;
  import org.activiti.engine.ActivitiOptimisticLockingException;
  import org.activiti.engine.impl.cmd.AcquireTimerJobsCmd;
  import org.activiti.engine.impl.interceptor.Command;
  import org.activiti.engine.impl.interceptor.CommandContext;
  import org.activiti.engine.impl.interceptor.CommandExecutor;
  import org.activiti.engine.impl.persistence.entity.TimerJobEntity;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  /**
   *
  
   */
  public class AcquireTimerJobsRunnable implements Runnable {
  
      private static Logger log = LoggerFactory.getLogger(AcquireTimerJobsRunnable.class);
  
      protected final AsyncExecutor asyncExecutor;
      protected final JobManager jobManager;
  
      protected volatile boolean isInterrupted;
      protected final Object MONITOR = new Object();
      protected final AtomicBoolean isWaiting = new AtomicBoolean(false);
  
      protected long millisToWait;
  
      public AcquireTimerJobsRunnable(AsyncExecutor asyncExecutor, JobManager jobManager) {
          this.asyncExecutor = asyncExecutor;
          this.jobManager = jobManager;
      }
  
      public synchronized void run() {
          log.info("{} starting to acquire async jobs due");
          Thread.currentThread().setName("activiti-acquire-timer-jobs");
  
          final CommandExecutor commandExecutor = asyncExecutor.getProcessEngineConfiguration().getCommandExecutor();
  
          while (!isInterrupted) {
              try {
                  final AcquiredTimerJobEntities acquiredJobs = commandExecutor.execute(
                      new AcquireTimerJobsCmd(asyncExecutor)
                  );
  
                  commandExecutor.execute(
                      new Command<Void>() {
                          @Override
                          public Void execute(CommandContext commandContext) {
                              for (TimerJobEntity job : acquiredJobs.getJobs()) {
                                  jobManager.moveTimerJobToExecutableJob(job);
                              }
                              return null;
                          }
                      }
                  );
  
                  // if all jobs were executed
                  millisToWait = asyncExecutor.getDefaultTimerJobAcquireWaitTimeInMillis();
                  int jobsAcquired = acquiredJobs.size();
                  if (jobsAcquired >= asyncExecutor.getMaxTimerJobsPerAcquisition()) {
                      millisToWait = 0;
                  }
              } catch (ActivitiOptimisticLockingException optimisticLockingException) {
                  if (log.isDebugEnabled()) {
                      log.debug(
                          "Optimistic locking exception during timer job acquisition. If you have multiple timer executors running against the same database, " +
                          "this exception means that this thread tried to acquire a timer job, which already was acquired by another timer executor acquisition thread." +
                          "This is expected behavior in a clustered environment. " +
                          "You can ignore this message if you indeed have multiple timer executor acquisition threads running against the same database. " +
                          "Exception message: {}",
                          optimisticLockingException.getMessage()
                      );
                  }
              } catch (Throwable e) {
                  log.error("exception during timer job acquisition: {}", e.getMessage(), e);
                  millisToWait = asyncExecutor.getDefaultTimerJobAcquireWaitTimeInMillis();
              }
  
              if (millisToWait > 0) {
                  try {
                      if (log.isDebugEnabled()) {
                          log.debug("timer job acquisition thread sleeping for {} millis", millisToWait);
                      }
                      synchronized (MONITOR) {
                          if (!isInterrupted) {
                              isWaiting.set(true);
                              MONITOR.wait(millisToWait);
                          }
                      }
  
                      if (log.isDebugEnabled()) {
                          log.debug("timer job acquisition thread woke up");
                      }
                  } catch (InterruptedException e) {
                      if (log.isDebugEnabled()) {
                          log.debug("timer job acquisition wait interrupted");
                      }
                  } finally {
                      isWaiting.set(false);
                  }
              }
          }
  
          log.info("{} stopped async job due acquisition");
      }
  
      public void stop() {
          synchronized (MONITOR) {
              isInterrupted = true;
              if (isWaiting.compareAndSet(true, false)) {
                  MONITOR.notifyAll();
              }
          }
      }
  
      public long getMillisToWait() {
          return millisToWait;
      }
  
      public void setMillisToWait(long millisToWait) {
          this.millisToWait = millisToWait;
      }
  }
  