@Override
  public void close() throws LockException {
    for (HiveLock lock : locks) {
      unlock(lock);
    }
    locks.clear();
  }
Used to make another attempt to acquire a lock (in Waiting state)
@param extLockId
@return result of the attempt
@throws LockException
ql/src/java/org/apache/hadoop/hive/ql/lockmgr/DbLockManager.java