The AERTDLI interface

When you use the AERTDLI interface, the AIB used for database calls must be the same AIB as used for the APSB call. Specify the PCB that is requested for the call by placing the PCB name (as defined by PSBGEN) in the resource name field of the AIB. You do not specify the PCB address. Because the AIB contains the PCB name, your application can refer to the PCB name rather than to the PCB address. The AERTDLI call allows you to select PCBs directly by name rather than by a pointer to the PCB. At completion of the call, the AIB returns the PCB address that corresponds to the PCB name that is passed by the application program.

For PCBs to be used in a AERTDLI call, you must assign a name in PSBGEN, either with PCBNAME= or with the name as a label on the PCB statement. PCBs that have assigned names are also included in the positional pointer list, unless you specify LIST=NO. During PSBGEN, you define the names of the DB PCBs and alternate PCBs. All I/O PCBs are generated with the PCB name IOPCBbbb.

Because you pass the PCB name, you do not need to know the relative PCB number in the PCB list. In addition, the AERTDLI interface enables your application program to make calls on PCBs that do not reside in the PCB list. The LIST= keyword, which is defined in the PCB macro during PSBGEN, controls whether the PCB is included in the PCB list.

The AIB resides in user-defined storage that is passed to IMS for DL/I calls that use the AERTDLI interface. When the call is completed, the AIB is updated by IMS. Because some of the fields in the AIB are used internally by IMS, the same APSB AIB must be used for all subsequent calls for that PSB.