Macro Level Interpreter FAQ
Is macro level code keeping you on CICS 2.3?
With MLI do you have to make any application modifications or changes?
Does MLI support the CICS/ESA storage protect feature?
Does MLI support Dynamic Attach?
What is the Stub size?
Does MLI support mixed mode programs?
Does MLI support all standard DFH calls?
How does MLI stand up to high volume usage and does MLI create CPU overhead?
Does MLI support ISAM compatibility or unblocked files under CICS/ESA?
Does MLI co-exist with debugging tools?
1. With MLI do you have to make any application modifications or changes?
No. MLI installs as an application to CICS and intercepts macro calls and ADDRESS command calls (including ADDRESS CSA) automatically at program run time. No modification to program source or load module is required.
2. Does MLI support the CICS/ESA storage protect feature?
Yes. MLI fully supports Storage Protection in CICS/ESA 3.3 and above with no CPU overhead!
3. Does MLI support Dynamic Attach?
Yes. Whether referring to DFHKC TYPE=ATTACH or to the Dynamic Attachment of the STUB for macro level programs, their answer is yes. The stub attachment mechanism automatically recognizes mixed mode programs and pure command level programs to avoid double stub conditions and attaches a stub only to macro level programs.
4. What is the Stub size?
MLI stubs are necessary only for pure macro level programs and are 40 bytes for assembler programs and 72 bytes for COBOL programs. For PL/1 programs, the existing CICS stub is reused.
5. Does MLI support mixed mode programs?
Yes. MLI supports programs that have a mixture of macro and command level code.
6. Does MLI support all standard DFH calls?
Yes. The keyword is standard. DFHWTO, DFHOC, etc... system calls are supported as well as most CTYPE LOCATE and BROWSE calls.
7. How does MLI stand up to high volume usage and does MLI create CPU overhead?
MLI has a number of performance options that can be customized by the user. One option is the DIRECT LINK feature which can improve performance to the point where CPU consumption will be less with MLI and CICS/ESA than it was without MLI and CICS 2.1.2!
8. Does MLI support ISAM compatibility or unblocked files under CICS/ESA?
Yes. With CICS/ESA 4.1 unblocked files are no longer supported. However, MLI provides a user friendly menu where the user can code the DDNAME of files that need to be defined as unblocked. This process is automated under 2.1.2 and 3.3 CICS regions using RDM.
9. Does MLI co-exist with debugging tools?
MLI fully supports MacKinney's Track debugger. You'll need to check with vendors of other debuggers (Intertest, Expeditor, et al) for their compatibility with MLI.
Track is a full-featured interactive debugger supporting programs running under MLI at a very affordable price.