V$LOCK_ACTIVITY

Columns
   ___________________________
 

   COUNTER
   FROM_VAL
   TO_VAL
   ACTION_VAL

Related:

V$ENQUEUE_LOCK 
V$LATCH 
V$LOCK 
V$_LOCK
V$LOCKED_OBJECT 
V$LOCKS_WITH_COLLISIONS 
V$LOCK_ELEMENT 
V$RESOURCE  
V$TRANSACTION_ENQUEUE