Preparing the exit

Before the exit can be used it must be assembled and link-edited, and the load module placed in a library in the standard search order. ASMAXADT, as supplied, has the following attributes: reusable, reenterable, amode(24), rmode(24).

Refer to Providing user exits for further information about coding and preparing user exits.

Preparing the Filter Management Table: The names of the filter modules to be invoked by the user exit are contained in the Filter Management Table (FMT). The FMT is generated by using the macro ASMAXFMB. The names of the filter modules are specified as operands to the ASMAXFMB macro. Figure 1 shows an example of how to create an FMT that causes the filters MYFILT, YOURFILT, HERFILT, HISFILT, and OURFILT to be invoked by the exit.

Figure 1. Creating a filter management table

ASMAXFMT Title 'ADATA Exit Filter Management Table'
         ASMAXFMB MYFILT,YOURFILT,HERFILT,HISFILT,OURFILT
         END

The object file produced from the assembly must be link-edited, and the load module placed in a library in the standard search order. ASMAXFMT, as supplied, has the following attributes: reusable, non-reenterable, non-shareable.

You can specify an initial character string as part of the filter operand that is passed to the filter routine during initialization. Figure 2 shows two filter routines: MYFILT, that receives the characters “A,B,C”, and ASMAXFLU, that receives the characters “DUMP”.

Figure 2. Passing initial character string to filter routines

ASMAXFMT Title 'ADATA Exit Filter Management Table'
         ASMAXFMB (MYFILT,'A,B,C'),(ASMAXFLU,'DUMP')
         END

The default FMT control section (CSECT) name is ASMAXFMT. You can specify a different CSECT name using the SECT keyword on the ASMAXFMB macro. Figure 3 shows how to generate a CSECT name of MYFMT.

Figure 3. Generating an alternative CSECT name

ASMAXFMT Title 'ADATA Exit Filter Management Table'
         ASMAXFMB SECT=MYFMT,(MYFILT,'A,B,C'),YOURFILT
         END