docs: public void alarm(Object thandle)
    {
      if (TraceComponent.isAnyTracingEnabled() && tc.isEntryEnabled())
        SibTr.entry(tc, "alarm", new Object[] {this, mp.getMessagingEngineUuid()});
  
      synchronized (this)
      {
        if (!closed)
        {
          if ((executeSinceExpiry) || executing)
          { // has committed recently
            executeSinceExpiry = false;
          }
          else
          { // has not committed recently
            try
            {
              if (enqueuedUnits.size() > 0)
                startExecutingUpdates();
            }
            catch (ClosedException e)
            {
              // No FFDC code needed
              // do nothing as error already logged by startExecutingUpdates
            }
          }
        }
      } // end synchronized (this)
  
      if (maxCommitInterval > 0)
      {
        mp.getAlarmManager().create(maxCommitInterval, this);
      }
  
      if (TraceComponent.isAnyTracingEnabled() && tc.isEntryEnabled())
        SibTr.exit(tc, "alarm");
    }