Creating a data space does not give you access to the data space. You must use the ALESERV macro and issue certain assembler instructions before you can use the data space. The ALESERV macro adds an entry to an access list, either the DU-AL or the PASN-AL. The STOKEN parameter identifies the data space and the ALET parameter tells ALESERV where to return the access list entry token (that is, the ALET).
Your program can add entries for the data spaces it created or owns to either the DU-AL or the PASN-AL. Programs that the work unit represents can use the DU-AL. All programs running in the primary address space can use the PASN-AL for that address space. If you want all programs in the address space to have access to the data space entries, your program should put the entries on the PASN-AL. If you want to restrict the use of the entries, your program should put the entries on the DU-AL. When you add an entry to the PASN-AL, however, the system checks to see if an entry for that data space already exists on the PASN-AL. If the ALET is already on the PASN-AL, the system does not create a duplicate entry, but the program can still access the data space.
When your program wants to manipulate data in the data space, it places the ALET in an AR and changes its ASC mode to AR mode. For examples of how to establish addressability to data spaces and manipulate data in those data spaces, see Using access registers. The ALESERV macro describes how to add access list entries and gives an example.