gtpi1m11 | System Installation Support Reference |
User exit routine UCCDLAY is called during macro processing for an DLAYC or
YIELDC macro (if the
exit point named DLAY is active). The exit point is in CSECT
CCNUCL.
General Conditions at Entry
The registers at entry are:
- R6
- Type of macro calling this exit point.
- 01
- DLAYC macro call
- 02
- YIELDC macro call (for the READY list)
- 02
- YIELDC macro call (for the virtual file access count (VCT) list)
- R9
- Pointer to entry control block (ECB) page 1.
- R11-R15
- See User Exit Routines - Common Entry Conditions.
System Conditions at Entry
- System state
- Supervisor
- System mask
- Masked for I/O interrupts
- Protect key
- Working storage or zero (0)
- Address Space
- EVM.
Programming Considerations at Entry
See User Exit Routines - Common Programming Considerations for other considerations.
Programming Considerations on Return
- Intermediate processing contains code that performs special processing for
virtual machine (VM) and processor resource/systems manager (PR/SM)
environments. This processing can load a wait state program status word
(PSW) under certain conditions; load RC=4 to register 6 (R6) and return
to the caller if you want to bypass intermediate processing.
- DLAYC macro processing does not check to see if the ECB is holding any
resources. With the DLAYC macro entry user exit, you can determine
whether the ECB is holding any resources. Additionally, you can decide
to issue a system error or return to the issuing program without entering the
DLAYC macro. To ignore the delay request, load RC=8 to R6 and return to
the service routine. The service routine ignores the delay request and
returns to the program that issued the macro.
- See User Exit Routines - Common Return Conditions.
General Conditions on Return
- R6 must contain the return code that will be used by the calling service
routine to determine the next action.
- 0
- Continue normal processing.
- 4
- Bypass intermediate processing and go directly to delay processing.
- 8
- End the delay macro call and return to the macro caller.
- See User Exit Routines - Common Return Conditions.