Initialize and terminate the exit
If you write your exit in a high level language (HLL) such as COBOL or PL/I, very little work is needed to initialize or terminate the exit. Language Environment® initializes and preserves working storage for HLLs between calls.
If you write your exit in High Level Assembler (HLASM), you can use the Initialize and Terminate calls to get and release storage needed by the exit. The second argument in every call to the exit, the RAM-WORK-AREA-PTR, can be set by the exit at any time. File Manager preserves and passes this value with every call to the exit. This provides a way for the exit to gain addressability to its own storage on every call.