MATCTX (was Detecting changing objects...)

[bvining@xxxxxxxxxxxx]

If MATCTX was working prior to V4R3 for explicit libraries then the
bug is in the previous releases and not V4R3.  For many releases
there has been a restriction concerning passing system pointers to
system domain objects from user state programs (at higher security
levels); I suspect it is this restriction (the explict system pointer
to the context/library) that is causing the failure.

Because of this IBM provided the API QusMaterializeContext (you can
probably guess what it does based on the name) back in one of the V3
releases (it's in the V3R7 manual anyway).  This API is documented in
the Object APIs chapter of the System API Reference (though it basically
points you to the MI Functional Reference as the API is just a front end
to MATCTX that puts you into the proper state).  Other front ends of
this type exist, such as QusMaterializeJournalPortAttr in the Journal
and Commit APIs chapter).

Bruce

>
>A problem with MATCTX is that from V4R3M0 it seems to be
>a restricted operation (except when materializing the machine
>context - * ) and gives you a protection violation at security
>level 40 and above if your program is a user state program.
>Interestingly enough, the C function matctx does not have
>that problem. (I can hear the C-bigots snicker already).
>This is because the C interface goes through a service
>program that is not a user state program. As far as I am
>concerned thus is a bug. It does not make sense to
>have a restriction that is that easily circumvented. Maybe
>the bug has already been fixed in V4R4M0. If not, it
>either should be fixed or it should not be a restricted
>operation.
>


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