code: public void quiesceIfPossible() throws ResourceException {
  
          if (tc.isEntryEnabled()) {
              Tr.entry(this, tc, "quiesceIfPossible", _quiesce);
          }
          if (!_quiesce) { // only do this the first time we're called
              _quiesce = true;
              _quiesceTime = new Date(System.currentTimeMillis());
  
              //  Begin block copied from serverShutdown()
              for (int j = 0; j < maxFreePoolHashSize; ++j) {
                  synchronized (freePool[j].freeConnectionLockObject) {
                      /*
                       * If a connection gets away, by setting fatalErrorNotificationTime will
                       * guaranty when the connection is returned to the free pool, it will be
                       */
                      freePool[j].incrementFatalErrorValue(j);
                      /*
                       * Destroy as many connections as we can in the free pool
                       */
                      if (freePool[j].mcWrapperList.size() > 0) {
                          freePool[j].cleanupAndDestroyAllFreeConnections();
                      }
                  } // end free lock
              } //end for j
                // End block copied from serverShutdown()
  
          }
  
          if (totalConnectionCount.get() == 0) {
              quiesce();
          }
  
          if (tc.isEntryEnabled()) {
              Tr.exit(this, tc, "quiesceIfPossible");
          }
  
      }
docs: QuisceIfPossible should be called when a connection pool is no longer needed,
  instead of directly calling quiesce(). This method should be invoked the
  first time by ConnectionFactoryDetailsImpl.stop(). Subsequently it will
  be invoked at the end of PoolManager.release().
  
  This method does three things
  <UL>
  <LI> If _quiesce == false, set it to true and set _quiesceTime. </LI>
  <LI> If _quiesce == false, increment the fatal error value for every
  FreePool and purge any existing connections. </LI>
  <LI> If the connection pool is empty, call quiesce to completely clean up. </LI>
  </UL>