Information about loaded modules in common storage is serialized by the LOCAL and CMS locks. Information about other loaded modules is serialized by the LOCAL lock. When the CSVINFO service runs with serialization, you are guaranteed that the information CSVINFO obtains is not in the process of being updated.
If your program runs in problem state and invokes the CSVINFO macro, your program cannot hold the appropriate locks and the CSVINFO service does not obtain them. Thus, the CSVINFO service retrieves information without serializing on it. If you are requesting information about loaded modules in common storage or if multi-tasking is taking place in your address space, the module information you request might be changing while the CSVINFO service is retrieving information. In rare instances, the CSVINFO service could return incorrect information or end abnormally.
If your program runs in supervisor state and invokes the CSVINFO macro, the CSVINFO service obtains the appropriate locks if your program does not already hold them.