code: public void prepareUpdateStep1b() {
  
          if (!isInitialized()) {
              return;
          }
  
          if ((m_dbUpdateThread != null) && (m_dbUpdateThread.isFinished())) {
              // update is already finished, just wait for client to collect final data
              return;
          }
  
          if (m_dbUpdateThread == null) {
              m_dbUpdateThread = new CmsUpdateDBThread(this);
          }
  
          if (!m_dbUpdateThread.isAlive()) {
              m_dbUpdateThread.start();
          }
      }
docs: Prepares step 1 of the update wizard.<p>