Disabling Previously Supported Functions

You can use the disable request of the IEFSSVT macro to dynamically disable a function code so that your subsystem no longer gets control for that function. Disabling a function is in effect a "logical delete".

Attention: Because there is no serialization on updating the table in the SSVT, other requests for the supported functions might be coming in asynchronously. Therefore, it is important to not remove the function routines from storage.

When preparing to disable one or more function codes, consider:

When you will be invoking IEFSSVT.
Which of the existing function codes are no longer supported.

Inputs

Before invoking the IEFSSVT macro, the subsystem must use the IEFSSVTI macro to create a table that relates function routines and the function codes they support.

Unlike the enable request, the disable request does not use the name or address of the function routines in the subsystem vector table when disabling function codes. It uses only the function code itself.

If possible, the SSI reclaims the space in the subsystem vector table occupied by the function routines associated with the disabled function codes. If a function routine does not support any remaining function codes, the SSI makes its subsystem vector table space available for reuse in subsequent enable requests.