Derivation: RePorT SToraGe

RPTSTG generates, after an application has run, a report of the storage the application used. Language Environment writes storage reports only in mixed-case U.S. English.

You can use the storage report information to help you set the ANYHEAP, BELOWHEAP, HEAP, HEAP64, HEAPPOOLS, HEAPPOOLS64, IOHEAP64, LIBHEAP64, LIBSTACK, STACK, STACK64, THREADHEAP, THREADSTACK, and THREADSTACK64 runtime options for the best storage tuning. For an example and complete description of the storage report, see z/OS Language Environment Debugging Guide.

The default value for non-CICS applications is RPTSTG(OFF).

The default value for CICS® applications is RPTSTG(OFF).

The default value for AMODE 64 applications is RPTSTG(OFF).

Syntax

              .-OFF-.      
>>-RPTStg--(--+-----+--)---------------------------------------><
              '-ON--'      

OFF

Does not generate a report of the storage used while the application was running.

ON

Generates a report of the storage used while the application was running.

CICS consideration

• The phrases "Number of segments allocated" and "Number of segments freed" represent, on CICS, the number of EXEC CICS GETMAIN and EXEC CICS FREEMAIN requests, respectively.

z/OS® UNIX considerations

• The RPTSTG option applies to storage utilization for the enclave, including thread-level information about stack utilization, and heap storage used by multiple threads.

Usage notes

• For AMODE 64 applications, Language Environment writes the storage report to stderr.
• When a vendor heap manager (VHM) is active, the Language Environment Storage Report will have a text line indicating that the user heap for C/C++ part of the enclave is managed separately. The VHM is expected to write its own storage report to the stderr stream.
• In some cases, RPTSTG will not generate the storage report if your application ends abnormally.
• RPTSTG includes PL/I task-level information about stack and heap usage.
• The phrases "Number of segments allocated" and "Number of segments freed" represent the number of GETMAIN and FREEMAIN requests, respectively.

Performance consideration

• This option increases the time it takes for an application to run. Therefore, use it only as an aid to application development.
• The storage report generated by RPTSTG(ON) shows the number of system-level calls to obtain storage that were required while the application was running. To improve performance, use the storage report numbers generated by the RPTSTG option as an aid in setting the initial and increment size for stack and heap. This reduces the number of times that the Language Environment storage manager makes requests to acquire storage. For example, you can use the storage report numbers to set appropriate values in the HEAP init_size and incr_size fields for allocating storage.

For more information

• For more information about tuning your application with storage numbers, see z/OS Language Environment Programming Guide.
• For more information about the MSGFILE runtime option, see MSGFILE.
• For an example and complete description of the storage report, see z/OS Language Environment Debugging Guide.