output: #fixed code
                                public boolean waitForKeeperState(KeeperState keeperState, long time, TimeUnit timeUnit)
        throws ZkInterruptedException {
      validateCurrentThread();
      Date timeout = new Date(System.currentTimeMillis() + timeUnit.toMillis(time));
  
      LOG.debug("Waiting for keeper state " + keeperState);
      acquireEventLock();
      try {
        boolean stillWaiting = true;
        while (_currentState != keeperState) {
          if (!stillWaiting) {
            return false;
          }
          stillWaiting = getEventLock().getStateChangedCondition().awaitUntil(timeout);
        }
        LOG.debug("State is " + (_currentState == null ? "CLOSED" : _currentState));
        return true;
      } catch (InterruptedException e) {
        throw new ZkInterruptedException(e);
      } finally {
        getEventLock().unlock();
      }
    }
input: #vulnerable code 
                                public boolean waitForKeeperState(KeeperState keeperState, long time, TimeUnit timeUnit)
        throws ZkInterruptedException {
      if (_zookeeperEventThread != null && Thread.currentThread() == _zookeeperEventThread) {
        throw new IllegalArgumentException("Must not be done in the zookeeper event thread.");
      }
      Date timeout = new Date(System.currentTimeMillis() + timeUnit.toMillis(time));
  
      LOG.debug("Waiting for keeper state " + keeperState);
      acquireEventLock();
      try {
        boolean stillWaiting = true;
        while (_currentState != keeperState) {
          if (!stillWaiting) {
            return false;
          }
          stillWaiting = getEventLock().getStateChangedCondition().awaitUntil(timeout);
        }
        LOG.debug("State is " + (_currentState == null ? "CLOSED" : _currentState));
        return true;
      } catch (InterruptedException e) {
        throw new ZkInterruptedException(e);
      } finally {
        getEventLock().unlock();
      }
    } 
                              #location 3 
                              #vulnerability type THREAD_SAFETY_VIOLATION