gtpi1m1p | System Installation Support Reference |
User exit routine UCCPER is invoked whenever a PER program interrupt is
taken that matches the address range and event type requested for display by
the ZSPER command and the exit point named PER is active.
Exit point PER is contained in copy segment CPER of CSECT CCCPSE.
The PER exit point allows you to interrupt data and expand the amount of
data captured by the PER interrupt. The PER user exit logic issues a
SNAPC (with return) to write the PER data to tape. When the PER user
exit is not active, PER processing issues the SNAPC for the common set of
data.
General Conditions at Entry
The registers at entry to UCCPER are:
- R1
- Address of a 1-byte return flag used to show whether the PER interrupt
data should be processed or discarded by the ZSPER command.
- R3
- Address of the PER control area. The IDSPER macro can be used to
DSECT the control block.
- R6
- Address of the storage block containing the PER interrupt data. The
IDSPER macro can be used to DSECT the data block.
- R11-R15
- See User Exit Routines - Common Entry Conditions.
System Conditions at Entry
- System state
- Supervisor
- System mask
- Masked
- Protect key
- 0
- Address Space
- SVM.
Programming Considerations at Entry
- A PER interrupt can occur in either the SVM or the EVM.
- R9 may not contain a valid ECB address in the SVM.
- The PER hardware interface locations are unchanged.
- See User Exit Routines - Common Programming Considerations for other considerations.
Programming Considerations on Return
See User Exit Routines - Common Return Conditions.
General Conditions on Return
- To bypass additional processing of PER interrupt data by the ZSPER
command, set bit 0 of the byte at the address in R1 to 1
(X'80'). To continue processing the PER interrupt data, no
change is required. Regardless of the flag setting returned by this
exit, the PER interrupt may still be eligible for processing by the PER
debugging tools exit point (UCCPER2) or the TPF Assembler Debugger for
VisualAge Client.
- See User Exit Routines - Common Return Conditions.