Obtain address space related information (REQASD and REQFASD)

z/OS MVS Programming: Authorized Assembler Services Reference SET-WTO

Obtain address space related information (REQASD and REQFASD)

z/OS MVS Programming: Authorized Assembler Services Reference SET-WTO
SA23-1375-00

The SYSEVENTs REQASD and REQFASD provide information about an address space's workload activity. You must specify the address space id (ASID) with either the ASID=register or the ASIDL=asid parameter.

Both return the same kind of information. REQFASD is quicker; it does not serialize data collection, and does not provide recovery of its own. The user must provide the recovery for REQFASD.

The user must supply the address of a storage area large enough to hold the requested data.

REQASD

Returns workload activity information about an address space.

REQFASD

Returns the same information as REQASD, but is a fast path SYSEVENT, with no recovery of its own.

TYPE=SIZECHECK: Required parameter which activates work area size checking and should always be specified.

Input register information

REQASD

For REQASD, register 1 must point to a parameter list. The parameter list must be non-pageable and addressable via the caller's primary address space. To map the parameter list, use the IRARASD mapping macro described in z/OS MVS Data Areas in z/OS Internet Library at http://www.ibm.com/systems/z/os/zos/bkserv/.

The RASDLEN field must be filled in with the length of the RASD parameter list area that is to be used by the SYSEVENT. The constant RASDSIZE can be used to fill in the RASDLEN field.

REQFASD

For REQFASD, register 1 must point to a parameter list. The parameter list must be addressable via the caller's primary address space. To map the parameter list, use the IRARASD mapping macro described in z/OS MVS Data Areas in z/OS Internet Library at http://www.ibm.com/systems/z/os/zos/bkserv/.

The RASDLEN field must be filled in with the length of the RASD parameter list area that is to be used by the SYSEVENT. The constant RASDSIZE can be used to fill in the RASDLEN field.

SYSEVENT REQFASD requires a workarea for the processing. The size of the workarea can be found in the constant RQFASDWA, which is defined in the IRARASD mapping. Additionally, it is necessary to fill the RASDWALEN with the provided workarea length. Prior to executing REQFASD, register 13 must point to a workarea. The workarea must be addressable via the caller's primary address space.

Return and reason codes

When processing is complete for the REQASD and REQFASD SYSEVENTS, the last byte of register 15 contains one of the following hexadecimal return codes:

Table 1. Return Codes for REQASD and REQFASD
Return Code	Meaning
00	Successful completion.
04	Processing could not be completed at this time. A mode switch or policy activation is in progress. A later reissue could be successful.
08	The parameter list is too small.
12	The ASID is not valid.
16	Work area is too small (only issued by REQFASD).

Example 1

Use the SYSEVENT REQASD to extract address space information:

         LA    R1,Parmlist           Load parameter list address
         USING RASD,R1               Map parameter list with RASD
         MVC   RASDACRO,=C'RASD'     Set eyecatcher

         MVC   RASDLEN,=AL2(L'Parmlist) Set parameter list length
         SYSEVENT REQASD,TYPE=SIZECHECK,ENTRY=BRANCH,ASID=(0)
         ...
Parmlist DS    CL(RASDSIZE)

Example 2

Use the SYSEVENT REQFASD to extract address space information:

         LA    R1,Parmlist           Load parameter list address
         USING RASD,R1               Map parameter list with RASD
         MVC   RASDACRO,=C'RASD'     Set eyecatcher

         MVC   RASDLEN,=AL2(L'Parmlist) Set parameter list length
         MVC   RASDWALEN,=AL2(L'Workarea) and Workarea length in RASD
         LR    R2,R13                Save R13 prior Sysevent invocation
         LA    R13,Workarea          Address the workarea with R13
         SYSEVENT REQFASD,TYPE=SIZECHECK,ENTRY=BRANCH,ASID=(0)
         LR    R13,R2                Restore R13
         ...
Parmlist DS    CL(RASDSIZE)
Workarea DS    CL(RQFASDWA)