output: #fixed code
                                  @Override
      protected void process(ComplexEventChunk<StreamEvent> streamEventChunk, Processor nextProcessor,
                             StreamEventCloner streamEventCloner, ComplexEventPopulater complexEventPopulater) {
          ComplexEventChunk<StreamEvent> complexEventChunk = new ComplexEventChunk<StreamEvent>(false);
          lock.lock();
          try {
              while (streamEventChunk.hasNext()) {
                  StreamEvent event = streamEventChunk.next();
  
                  if(event.getType() != ComplexEvent.Type.TIMER) {
  
                      streamEventChunk.remove(); //We might have the rest of the events linked to this event forming a chain.
  
                      long timestamp = (Long) timestampExecutor.execute(event);
  
                      if (expireFlag) {
                          if (timestamp < lastSentTimeStamp) {
                              continue;
                          }
                      }
  
                      ArrayList<StreamEvent> eventList = eventTreeMap.get(timestamp);
                      if (eventList == null) {
                          eventList = new ArrayList<StreamEvent>();
                      }
                      eventList.add(event);
                      eventTreeMap.put(timestamp, eventList);
  
                      if (timestamp > greatestTimestamp) {
                          greatestTimestamp = timestamp;
                          long minTimestamp = eventTreeMap.firstKey();
                          long timeDifference = greatestTimestamp - minTimestamp;
  
                          if (timeDifference > k) {
                              if (timeDifference < MAX_K) {
                                  k = timeDifference;
                              } else {
                                  k = MAX_K;
                              }
                          }
  
                          Iterator<Map.Entry<Long, ArrayList<StreamEvent>>> entryIterator = eventTreeMap.entrySet().iterator();
                          while (entryIterator.hasNext()) {
                              Map.Entry<Long, ArrayList<StreamEvent>> entry = entryIterator.next();
                              ArrayList<StreamEvent> list = expiredEventTreeMap.get(entry.getKey());
  
                              if (list != null) {
                                  list.addAll(entry.getValue());
                              } else {
                                  expiredEventTreeMap.put(entry.getKey(), entry.getValue());
                              }
                          }
                          eventTreeMap = new TreeMap<Long, ArrayList<StreamEvent>>();
  
                          entryIterator = expiredEventTreeMap.entrySet().iterator();
                          while (entryIterator.hasNext()) {
                              Map.Entry<Long, ArrayList<StreamEvent>> entry = entryIterator.next();
  
                              if (entry.getKey() + k <= greatestTimestamp) {
                                  entryIterator.remove();
                                  ArrayList<StreamEvent> timeEventList = entry.getValue();
                                  lastSentTimeStamp = entry.getKey();
  
                                  for (StreamEvent aTimeEventList : timeEventList) {
                                      complexEventChunk.add(aTimeEventList);
                                  }
                              }
                          }
                      }
                  } else {
                      if(expiredEventTreeMap.size() > 0) {
                          TreeMap<Long, ArrayList<StreamEvent>> expiredEventTreeMapSnapShot = expiredEventTreeMap;
                          expiredEventTreeMap = new TreeMap<Long, ArrayList<StreamEvent>>();
                          onTimerEvent(expiredEventTreeMapSnapShot, nextProcessor);
                          lastScheduledTimestamp = lastScheduledTimestamp + TIMER_DURATION;
                          scheduler.notifyAt(lastScheduledTimestamp);
                      }
                  }
  
  
  
              }
          } catch (ArrayIndexOutOfBoundsException ec) {
              //This happens due to user specifying an invalid field index.
              throw new ExecutionPlanCreationException("The very first parameter must be an Integer with a valid " +
                      " field index (0 to (fieldsLength-1)).");
          }
          lock.unlock();
          nextProcessor.process(complexEventChunk);
      }
input: #vulnerable code 
                                  @Override
      protected void process(ComplexEventChunk<StreamEvent> streamEventChunk, Processor nextProcessor,
                             StreamEventCloner streamEventCloner, ComplexEventPopulater complexEventPopulater) {
          ComplexEventChunk<StreamEvent> complexEventChunk = new ComplexEventChunk<StreamEvent>(false);
          try {
              while (streamEventChunk.hasNext()) {
  
  
                  StreamEvent event = streamEventChunk.next();
  
                  if(event.getType() != ComplexEvent.Type.TIMER) {
  
                      streamEventChunk.remove(); //We might have the rest of the events linked to this event forming a chain.
  
                      long timestamp = (Long) timestampExecutor.execute(event);
  
                      if (expireFlag) {
                          if (timestamp < lastSentTimeStamp) {
                              continue;
                          }
                      }
  
                      ArrayList<StreamEvent> eventList = eventTreeMap.get(timestamp);
                      if (eventList == null) {
                          eventList = new ArrayList<StreamEvent>();
                      }
                      eventList.add(event);
                      eventTreeMap.put(timestamp, eventList);
  
                      if (timestamp > greatestTimestamp) {
  
                          greatestTimestamp = timestamp;
                          long minTimestamp = eventTreeMap.firstKey();
  
                          if ((greatestTimestamp - minTimestamp) > k) {
                              if ((greatestTimestamp - minTimestamp) < MAX_K) {
                                  k = greatestTimestamp - minTimestamp;
                              } else {
                                  k = MAX_K;
                              }
                          }
  
                          lock.lock();
                          Iterator<Map.Entry<Long, ArrayList<StreamEvent>>> entryIterator = eventTreeMap.entrySet().iterator();
                          while (entryIterator.hasNext()) {
                              Map.Entry<Long, ArrayList<StreamEvent>> entry = entryIterator.next();
                              ArrayList<StreamEvent> list = expiredEventTreeMap.get(entry.getKey());
  
                              if (list != null) {
                                  list.addAll(entry.getValue());
                              } else {
                                  expiredEventTreeMap.put(entry.getKey(), entry.getValue());
                              }
                          }
                          eventTreeMap = new TreeMap<Long, ArrayList<StreamEvent>>();
  
                          entryIterator =  expiredEventTreeMap.entrySet().iterator();
                          while (entryIterator.hasNext()) {
                              Map.Entry<Long, ArrayList<StreamEvent>> entry = entryIterator.next();
  
                              if (entry.getKey() + k <= greatestTimestamp) {
                                  entryIterator.remove();
                                  ArrayList<StreamEvent> timeEventList = entry.getValue();
                                  lastSentTimeStamp = entry.getKey();
  
                                  for (StreamEvent aTimeEventList : timeEventList) {
                                      complexEventChunk.add(aTimeEventList);
                                  }
                              }
                          }
                          lock.unlock();
                      }
                  } else {
                      onTimerEvent(expiredEventTreeMap, nextProcessor);
                      lastScheduledTimestamp = lastScheduledTimestamp + TIMER_DURATION;
                      scheduler.notifyAt(lastScheduledTimestamp);
                  }
  
  
  
              }
          } catch (ArrayIndexOutOfBoundsException ec) {
  //            This happens due to user specifying an invalid field index.
              throw new ExecutionPlanCreationException("The very first parameter must be an Integer with a valid " +
                      " field index (0 to (fieldsLength-1)).");
          }
  
          nextProcessor.process(complexEventChunk);
      } 
                              #location 32 
                              #vulnerability type THREAD_SAFETY_VIOLATION