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TDEPLOCK
If you have a task suspended on resource type TDEPLOCK, with a resource name corresponding to a transient data queue name, the task has issued a request against an extrapartition transient data queue. Another task is already accessing the same queue, and the waiting task cannot resume until that activity is complete.
If the wait is prolonged, it could be for either of these reasons:
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It is necessary for a task to change TCB mode to open and close a data set. The task must relinquish control while this happens, and, depending on the system loading, this might take several seconds. This contributes to the wait that the second task, suspended on resource type TDEPLOCK, experiences.
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CICS uses the access method QSAM to write data to extrapartition transient data destinations. QSAM executes synchronously with tasks requesting its services. This means that any task invoking a QSAM service must wait until the QSAM processing is complete. If, for any reason, QSAM enters an extended wait, the requesting task also experiences an extended wait.
The possibility of an extended wait arises whenever QSAM attempts to access an extrapartition data set. QSAM uses the MVS RESERVE volume-locking mechanism to gain exclusive control of volumes while it accesses them, which means that any other region attempting to write to the same volume is forced to wait.
If tasks frequently get suspended on resource type TDEPLOCK, you need to determine which other transactions write data to the same extrapartition destination. You might then consider redefining the extrapartition destinations.