def METHOD_NAME(event):
    """
    Issue a lock on this event so nobody can book tickets for this event until
    you release the lock. Will retry 5 times on failure.
    :raises LockTimeoutException: if the event is locked every time we try
                                  to obtain the lock
    """
    if hasattr(event, '_lock') and event._lock:
        return True
    if settings.HAS_REDIS:
        return lock_event_redis(event)
    else:
        return lock_event_db(event)