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.AcquireJobsCmd;
  import org.activiti.engine.impl.interceptor.CommandExecutor;
  import org.activiti.engine.impl.persistence.entity.JobEntity;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  /**
   *
  
   */
  public class AcquireAsyncJobsDueRunnable implements Runnable {
  
      private static Logger log = LoggerFactory.getLogger(AcquireAsyncJobsDueRunnable.class);
  
      protected final AsyncExecutor asyncExecutor;
  
      protected volatile boolean isInterrupted;
      protected final Object MONITOR = new Object();
      protected final AtomicBoolean isWaiting = new AtomicBoolean(false);
  
      protected long millisToWait;
  
      public AcquireAsyncJobsDueRunnable(AsyncExecutor asyncExecutor) {
          this.asyncExecutor = asyncExecutor;
      }
  
      public synchronized void run() {
          log.info("{} starting to acquire async jobs due");
          Thread.currentThread().setName("activiti-acquire-async-jobs");
  
          final CommandExecutor commandExecutor = asyncExecutor.getProcessEngineConfiguration().getCommandExecutor();
  
          while (!isInterrupted) {
              try {
                  AcquiredJobEntities acquiredJobs = commandExecutor.execute(new AcquireJobsCmd(asyncExecutor));
  
                  boolean allJobsSuccessfullyOffered = true;
                  for (JobEntity job : acquiredJobs.getJobs()) {
                      boolean jobSuccessFullyOffered = asyncExecutor.executeAsyncJob(job);
                      if (!jobSuccessFullyOffered) {
                          allJobsSuccessfullyOffered = false;
                      }
                  }
  
                  // If all jobs are executed, we check if we got back the amount we expected
                  // If not, we will wait, as to not query the database needlessly.
                  // Otherwise, we set the wait time to 0, as to query again immediately.
                  millisToWait = asyncExecutor.getDefaultAsyncJobAcquireWaitTimeInMillis();
                  int jobsAcquired = acquiredJobs.size();
                  if (jobsAcquired >= asyncExecutor.getMaxAsyncJobsDuePerAcquisition()) {
                      millisToWait = 0;
                  }
  
                  // If the queue was full, we wait too (even if we got enough jobs back), as not overload the queue
                  if (millisToWait == 0 && !allJobsSuccessfullyOffered) {
                      millisToWait = asyncExecutor.getDefaultQueueSizeFullWaitTimeInMillis();
                  }
              } catch (ActivitiOptimisticLockingException optimisticLockingException) {
                  if (log.isDebugEnabled()) {
                      log.debug(
                          "Optimistic locking exception during async job acquisition. If you have multiple async executors running against the same database, " +
                          "this exception means that this thread tried to acquire a due async job, which already was acquired by another async executor acquisition thread." +
                          "This is expected behavior in a clustered environment. " +
                          "You can ignore this message if you indeed have multiple async executor acquisition threads running against the same database. " +
                          "Exception message: {}",
                          optimisticLockingException.getMessage()
                      );
                  }
              } catch (Throwable e) {
                  log.error("exception during async job acquisition: {}", e.getMessage(), e);
                  millisToWait = asyncExecutor.getDefaultAsyncJobAcquireWaitTimeInMillis();
              }
  
              if (millisToWait > 0) {
                  try {
                      if (log.isDebugEnabled()) {
                          log.debug("async job acquisition thread sleeping for {} millis", millisToWait);
                      }
                      synchronized (MONITOR) {
                          if (!isInterrupted) {
                              isWaiting.set(true);
                              MONITOR.wait(millisToWait);
                          }
                      }
  
                      if (log.isDebugEnabled()) {
                          log.debug("async job acquisition thread woke up");
                      }
                  } catch (InterruptedException e) {
                      if (log.isDebugEnabled()) {
                          log.debug("async 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;
      }
  }
  