Routine binding restrictions
If you bind DL/I exit routines, you must keep in mind the recommendations and restrictions in this information.
Most modules receive control and must return control in AMODE=31, and must be able to execute in cross-memory and TASK modes.
- RMODE=ANY is recommended.
- All TM exit routines can be entered simultaneously by multiple dispatchable tasks. Therefore, it is highly recommended that all TM exit routines are coded as reentrant (RENT).
All routines receive control and must return control in 31-bit addressing mode (AMODE 31) and must be able to execute in RMODE ANY and AMODE 31.
If you bind an exit routine as reentrant (RENT), it must be truly reentrant (for example, it cannot depend on any information from a previous iteration and it cannot store into itself).
If you bind an exit routine as reusable (REUSE), it must be truly reusable (it cannot depend on any information in itself from a previous iteration), but it can depend on information that it saves in the specific block passed to it. If you bind a routine that is serially reusable, it must be used for a single database only.
If you bind an exit routine as neither RENT nor REUSE, it can store into itself and depend on the information saved in the block that is passed to it.
If you bind an exit routine as reentrant, it is loaded in key 0 storage to automatically protect the exit routine from being accidentally or intentionally modified.
Specific requirements
and exceptions are noted in each topic. Refer to the topic on Binding
the Routine
included in each exit routine section.