Input Parameter Fields

The meaning and use of each of the input parameter fields are described below. The Sampling Engine places data into these fields used by the exit to complete the function call.

DEXMRI_Eye

This field contains an eye catcher and identifies this entire parameter block. It contains ‘DEXMRPB _’. The exit can use this field to verify the parameter list. It can also be used to find the parameter block in a dump.

DEXMRI_Functn

This field contains the code of the function to be performed by the exit. Refer to item 5 in Data Extractor Module Resolution Program Design Considerations for additional information. There are three function codes:

1. DEXMRI_FFirst - indicates that this is a First time or initialization call. The exit is called with this function code once at the start of the sampling session.
2. DEXMRI_FMR - indicates that this is a Module Resolution call. The exit is called once per unresolved address.
3. DEXMRI_FLast- indicates that this is Last or termination call. The exit is called with this function code once at the end of the sampling session. The exit should use this opportunity to clean up its environment.

DEXMRI_Versn

This field contains the version of the entire parameter block. The exit can use this value to ensure that parameter block it expects is at the correct version. This protects the exit from changes to the parameter block.

DEXMRI_PLen

This field contains the length of the entire parameter block. The exit can use this value to ensure that parameter block it expects is at the correct version. This protects the exit from changes to the parameter block.

DEXMRI_Flags

This field contains some flag bits.

1. DEXMRI_FLLock – Indicates that the exit is called with the local lock held.

DEXMRI_ContxtL

This field contains the length of the context area provided by Application Performance Analyzer for the exclusive use of the exit.

DEXMRI_Contxt@

This field contains the address of the context area.

DEXMRI_StepPGM

This field contains the Job Step program name. The exit can use this field to determine if it is interested in monitoring this Job Step. If not, the exit can return with a return code of DEXMRO_RCNCall, indicating to the Sampling Engine to not call the exit again until the Last (or termination) call.

DEXMRI_Address

This field contains the sampled PSW (instruction) address. It is the address that the Sampling Engine requires the exit to resolve to a load module or USS exec.

DEXMRI_TCB@

This field contains the address of the TCB under which the sampled PSW address was found.

DEXMRI_ASID

This field contains the address space ID of the sampled address space.

DEXMRI_SASID

This field contains the address space ID of the address space where the PSW address was sampled. Typically, this is the same as DEXMRI_ASID. The exit can decide to compare the two ASIDs to determine if it is interested in resolving the address.