gtpi1m13 | System Installation Support Reference |
User exit routine UCCCENV is used with ISO-C support. UCCCENV is
activated when an ISO-C environment is initially created for a given ECB after
all ISO-C control structures have been initialized, if the exit point named
CENV is active. User exit CENV is called from an ISO-C
environment. Exit point CENV is called from the dynamic load module
(DLM) startup code (CSTRTD) of the CLMINT segment in the CIS0 library.
Some possible uses of this exit point include:
- To increase the size of the language work space (LWS)
- To load a default locale that is different than the C/370 locale.
General Conditions at Entry
The registers at entry to UCCCENV are:
- R5
- 0.
- R8
- Points to the DLM header.
- R9
- Address of the ECB.
- R13-R15
- See User Exit Routines - Common Entry Conditions.
The relevant ECB fields at entry to UCCCENV are:
- CE2ISOC
- Address of the Task Communication Area (TCA)
- CE3SPTR
- Address of the Data Save Area (DSA).
System Conditions at Entry
- System state
- Problem (see Programming Considerations at Entry, item 2)
- System mask
- Unmasked (see Programming Considerations at Entry, item 2)
- Protect key
- Working storage
- Address state
- EVM.
Programming Considerations at Entry
- The language work space (LWS) area cannot be incremented past the end of
the stack (EOS) field in the task communication area (TCA).
- Usually, the system state, system mask, and protection key
are as stated. However, there can be exceptions if system programs
issued MONTC to get to supervisor state, changed the system mask, or changed
the protection key.
- 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
- If you need a locale that is different from the default locale, use R5 to
indicate the locale. For EDCLOC-based locales, R5 must contain the name
of the module that contains the locale. For localedef
utility-based locales, R5 must contain the 4-character internal name of the
locale.
- See User Exit Routines - Common Return Conditions.