Adding an Entry for the Primary Address Space to the DU-AL

A program can use the ADDPASN parameter on ALESERV to add an entry for the primary address space to the program's DU-AL. For example, consider the setup in Figure 1. TCB A represents PGM1 (in the home address space), PGM2 (currently executing in AS2), PGM3, and PGM4. In other words, all the PC routines shown run under the same TCB with the same DU-AL. PGM3 and PGM4 can use an ALET of 2 to reference the home address space. However, no special ALET exists for PGM3 and PGM4 to reference AS2.

PGM2, without having EAX-authority to the address space, can issue ALESERV ADDPASN to place an entry for AS2 on the DU-AL. This action gives PGM3 and PGM4 addressability to AS2, providing the ALETs are passed to these programs.

Figure 1. Obtaining the ALET for the Primary Address Space

In the following example, a program adds an entry for the primary address space to the DU-AL as a public entry.

ADDPASN  CSECT
ADDPASN  AMODE 31
ADDPASN  RMODE ANY
         BAKR  14,0                    SAVE CALLER'S STATUS ON STACK
         SAC   512                     SWITCH INTO AR MODE
         .
         LAE   12,0                    SET BASE REGISTER AR
         BASR  12,0                    SET BASE REGISTER GR
         USING *,12
         SYSSTATE ASCENV=AR
         .
*  ADD PROGRAM'S PASN AS PUBLIC TO THE PROGRAM'S DU-AL
         ALESERV ADDPASN,ALET=PGMALET
         .
*  BODY OF PROGRAM
         .
*  REMOVE PROGRAM'S PASN FROM DU-AL
         ALESERV DELETE,ALET=PGMALET   REMOVE PASN FROM DU-AL
         .
         PR                            RETURN TO CALLER
         .
PGMALET  DC   F                        ALET FOR PROGRAM'S PASN
         END