z/TPF Program Management - IBM

Terminal Addr Index into Selective Activation Table
------------- ------------------
020103 0
030567 0, 1
002203 1
292834 1, 2
Figure 11. Selective activation index example
Create a disable command
92 z/TPF Program Management
Note: Figure 11 contains a list of ECB origins (terminal addresses) and the
associated index into the selective activation table. In this example, ECBs
originating on terminal 292834 can enter programs and files from loadsets
Sally or Fred1.
The user-defined disable command should stop an ECB from using a loadset. This
message should remove the index pointer for the selective activation index entry,
and if there are no more index entries that reference the specified loadset, remove
the associated selective activation table entry (if there are no more ECB origins that
reference a loadset, there is no longer a need to maintain the activation number in
the selective activation table). If there are no more loadsets enabled to be used by
the specified ECB origin, then the index entry can be removed. By removing the
table index from the index entry, ECBs originating from that origin will not have the
specified loadset's activation number in their activation number list (which is used
by Enter / Back to determine which version of a program or file to use). If a file
copy of the mapping structure is maintained, then it will have to be updated to
reflect the disable request.
Note: It is entirely possible that the loadset name will not be found in either table.
The user-written disable code should handle this condition. This can occur
for 2 reasons:
1. The loadset was selectively activated, but never enabled. Here, a table
entry for the loadset was never created.
2. It is possible that the loadset was enabled; however, the mapping
structure is not recorded on file (for example, the enables do not survive
an IPL). If an IPL were to occur after the enable and before the disable
request, the disable code would not find the loadset in the tables.