code: protected void stopAllActiveSubWorkUnits() {
  
          for (String key : executingSubWorkUnits.keySet()) {
              try {
                  logger.fine("Issuing stop for sub job : " + key + " because the batch component is deactivating.");
                  //Do we need a null check here ?
                  //since we use a concurrentHashMap, and since a stop call doesn't mark a thread completed,
                  //safe to assume we won't find a null executingSubWorkUnit
                  stopWorkUnit(executingSubWorkUnits.get(key).batchWorkUnit);
              } catch (Exception e) {
                  // FFDC it.  Could be the job just finished.  In any event,
                  // continue on and stop the remaining jobs.
              }
          }
      }
docs: Stop all active executions in executingWorkUnitSets.