When your IXLLIST request causes contention, the system does the following:

1. Suspends your unit of work or processes your IXLLIST request asynchronously.
   • If you specified MODE=SYNCSUSPEND, the system suspends your unit of work until the lock is available and your request can be processed.
   • If you specified any other MODE value, the system processes your request asynchronously. You are informed of request completion by the method specified on the MODE parameter.
2. Queues your request on a sysplex-wide queue for the lock. Requests on each queue usually are processed in FIFO order. However, lock operations such as those issued in recovery processing for a failed connection, preempt the lock requests on the queue.
3. Gives control to the lock owner's notify exit to inform the connection of the lock contention (described in the topic "The Notify Exit").