Defining a named counter options table

When a pool selector value is encountered for the first time, the pool name is determined via the options table. The name is then saved and used for all subsequent requests for the same pool selector from the same TCB. This continues for the life of the TCB or until the NC_FINISH function is used specifying that pool selector value. CICS® supplies a default DFHNCOPT in source form, which you can customize and generate using the DFHNCO macro. A typical use of the options table is to enable production and test regions to use a different counter pool without needing to change the pool name in application programs.

To avoid the need to maintain multiple versions of the options table, you can use table entries to select pools based not only on the pool selection parameter specified on the DFHNCTR call, but also on the job name and APPLID of the CICS region. You can also specify the name of a user exit program to be called to make the pool selection.

Define an options table using one or more invocations of the DFHNCO macro. Each invocation generates an options table entry that defines the pool name or user exit program to be used whenever any selection conditions specified on the entry satisfy an application program request. The first entry automatically generates the table header, including the CSECT statement. Follow the last entry with an END statement specifying the table module entry point, DFHNCOPT.