Howto check the Locked objects?

Howto check the Locked objects?

SELECT b.session_id AS sid,
       NVL(b.oracle_username, '(oracle)') AS username,
       a.owner AS object_owner,
       a.object_name,
       Decode(b.locked_mode, 0, 'None',
                             1, 'Null (NULL)',
                             2, 'Row-S (SS)',
                             3, 'Row-X (SX)',
                             4, 'Share (S)',
                             5, 'S/Row-X (SSX)',
                             6, 'Exclusive (X)',
                             b.locked_mode) locked_mode,
       b.os_user_name
FROM   dba_objects a,
       v$locked_object b
WHERE  a.object_id = b.object_id
ORDER BY 1, 2, 3, 4;