When you write a data item to the cache structure, you can request the cast-out lock for the data item.

To obtain the cast-out lock, code GETCOLOCK=YES on the IXLCACHE request. When you obtain the cast-out lock, you identify your connection and, optionally, a process (such as a task) as the holder of the lock. You specify your process on the PROCESSID keyword. (The system can return the id, along with the cast-out lock, on certain IXLCACHE requests to the answer area.) While you hold the cast-out lock, if another user invokes a cache service that returns the value of the cast-out lock in the answer area, that user can identify, not only the connection, but also the task or process that holds the lock.