gtpi1m2g | System Installation Support Reference |
User exit routine UCCCTRC is invoked by the C function trace program
entry breakpoints and program exit breakpoints service
routine (CTR2) and by the C function trace other breakpoints service routine
(CTRY). This user exit is invoked after the trace entry is inserted
into the C function trace table, to allow the user to insert additional trace
data into the optional C function trace user area.
General Conditions at Entry
The registers at entry to UCCCTRC are:
- R2
- TCA address
- R3
- For program entry breakpoints - DSA address of the caller
For program exit breakpoints - current DSA address
For other breakpoints - current DSA address
- R5
- CID address
- R6
- Breakpoint type, defined in IDSCTR
- R8
- Current DLM address
- R9
- ECB pointer
- R11-R15
- See User Exit Routines - Common Entry Conditions.
System Conditions at Entry
- System state
- Unknown
- System mask
- Unmasked
- Protect key
- Unknown
- Address space
- EVM.
Programming Considerations at Entry
See User Exit Routines - Common Programming Considerations.
- You can issue the ENATC macro from the CTRC user exit. However, the
ENATC macro uses register 15 to provide return code information. This
use of register 15 conflicts with the user exit usage of register 15 for
addressing. Therefore, before you issue the ENATC macro from the CTRC
user exit, establish addressability using a base register other than
15.
- Note:
- You cannot issue the SETTC macro while processing the CTRC user exit routine
because the trace table environment has already been set up.
- If the offline dump processing code references the user data words (which
are the output in registers 5 and 6) as storage locations, you should use
storage offsets instead of storage addresses. The reason for this
restriction is that the offline dump processing loads the C function trace
area from tape into MVS storage, which is not the original TPF storage
addresses.
Programming Considerations on Return
User data first full word optionally updated by the user exit; the
value in R5 will be saved in the first word of the trace entry field
(ICTRE_USR) upon return from the user exit.
User data second full word optionally updated by the user exit; the
value in R6 will be saved in the second word of the trace entry field
(ICTRE_USR) upon return from the user exit.
See User Exit Routines - Common Return Conditions.
General Conditions on Return
See User Exit Routines - Common Return Conditions.