CICS Considerations

>You can access CA IDMS/DB from a CICS DL/I application at call level or command-level depending on how your DL/I applications are coded.
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You can access CA IDMS/DB from a CICS DL/I application at call level or command-level depending on how your DL/I applications are coded.
If call-level DL/I statements are utilized, DL/I applications can be relinked using the CA IDMS DLI Transparency CICS application interface (IDMSDL1C for z/OS, IDMSDL1V for z/VSE).
If command-level DL/I statements are utilized (EXEC DLI), DL/I applications can be relinked using a CA IDMS DLI Transparency CICS application interface specific to the application programming language and operating system.
For a description of IDMSDL1C, IDMSDL1V, and command-level DL/I application interfaces, see Runtime Interface.
DL/I CICS Environment
CICS DL/I Environment (z/OS)
As shown in the diagram, following, the native DL/I application runs as a CICS transaction.The transaction is linked with the DL/I language interface (DFHDLIAI in z/OS or DLZLI000 in z/VSE) so that it can make DL/I calls. When the transaction starts:
  • The language interface loads the address for DFHDLI (or DLZDLI for z/VSE) in the CICS Common Storage Area (CSA)
  • DFHDLI (or DLZDLI for z/VSE), in turn, points to the address of the run-time DL/I
  • When the transaction issues a DL/I call, the call is passed, via DFHDLIAI and DFHDLI, to DL/I, which services the database request and passes status information and/or data back to the transaction
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CA IDMS DLI Transparency CICS Environment
z/OS CICS Environment (Using Command-Level CICS services)
The diagram, following, shows the z/OS CICS environment for CA IDMS DLI Transparency using command-level CICS services.
  • The CA IDMS DLI Transparency application interface(also referenced as the language interface), intercepts DL/I calls.
  • The application interface gets the entry point address of IDMSDLFC (in IDMSINTC) from the CWA and passes control to IDMSDLFC for DL/I parameter processing
  • IDMSINTC passes control to the CA IDMS DLI Transparency back-end module, RHDCDLBE, for DL/I call translation into processing against the CA IDMS/DB database
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Establishing the CA IDMS DLI Transparency CICS Environment
How to Set Up a CA IDMS DLI Transparency CICS Environment
To set up a CICS environment for CA IDMS DLI Transparency, perform the following steps, which are explained in detail in the section directly after this:
  1. Assemble the CICSOPTS module with parameter ESCDLI=YES. .
  2. If applications utilize EXEC DLI calls, change the HLPI= parameter to YES.
  3. Assemble the appropriate language interface module.
  4. Link the DL/I application to the language interface module.
Use Appropriate CICS Language Interface
CICS DL/I applications
must be
re-linked with a CA IDMS DLI Transparency application/language interface module. For call-level DL/I usage, IDMSDL1C (z/OS) and IDMSDL1V (Z/VSE) resolve the external references to CBLTDLI, ASMTDLI, or PLITDLI.For EXEC DLI usages, the interface modules are language and operating system specific.For information on assembling language interface modules, see CA IDMS DLI Transparency JCL. Note that the interface modules must be assembled with a CWADISP value matching the corresponding CICSOPTS CWADISP value.
Assemble CICSOPTS
Initial Installation
A site-specific CICSOPTS module will be assembled and link edited as part of the installation process. All parameters for CICSOPTS that are required for the DL/I Transparency will be automatically generated by the CAISAG (z/OS) or CAIIJMP (z/VSE) installation utility when you indicate the product to be installed. The site-independent IDMSINTC module will include all modules specifically required to run the DLI/Transparency.
Modifying CICSOPTS
You may need to reassemble CICSOPTS to change some of the original installation options.
z/OS can find the CICSOPTS source in CUSTOM.SRCLIB(CICSOPTS) and the link statements in CUSTOM.LNKLIB(IDMSINTC).
z/VSE clients should edit the CICSOPTS module and relink IDMSINTC. Job control to do this should be taken from the job control that was generated by CAIIJMP for your initial base tape installation.
For more information on the CICSOPTS macro and its parameters, see the
CA IDMS System Operations Section.
IDMSINTC is the standard CA IDMS/DB module for running CA IDMS/DB transactions under CICS.CICSOPT parameter ESCDLI=YES specifies that you want to run not only standard CA IDMS/DB, but also CA IDMS DLI Transparency, under CICS. The result of ESCDLI=YES is to expand CICSOPTS, so that it can also serve as the CA IDMS DLI Transparency front end. If applications utilize EXEC DLI statements, HLPI=YES enables support for this DL/I usage. Note that it is possible to link IDMSCINT with a transaction to allow the transaction to make both CA IDMS/DB and DL/I calls.
Prepare to run IDMSINTC in CICS
IDMSINTC itself runs as a transaction under CICS. For a detailed description of how to prepare for this, see the
CA IDMS System Operations Section
.
Note that IDMSINTC can be executed either automatically at CICS start-up or sectionly after CICS start-up.
Assemble the language interface
Initial Installation
Language interfaces are automatically generated at installation. The appropriate language interface must be linked with each CICS DL/I application that will access CA IDMS/DB. The value for CWADISP will be set to the same value that was specified in the CICSOPTS assembly by the CAISAG (z/OS) or CAIIJMP (z/VSE) utility.
Modifying Language Interfaces
If you change the CWADISP value used by IDMSINTC, you will need to make the same change to the language interfaces being utilized.
For a description of the language interfaces, see Runtime Interface. For information on assembling CICS language interface modules, see CA IDMS DLI Transparency JCL .
z/OS can find the IDMSDL1C source in CUSTOM.SRCLIB and the IDMSSCL1C link statements in the CUSTOM.LNKLIB.
z/VSE clients should make the necessary change to the z/VSE DL/I language interfaces, using the job control that was generated by CAIIJMP as part of your initial base tape installation.
You will need to relink any DL/I application that included the language interfaces.