Re: C Service Pgm -- RPG400-L

Hello Sharon,

I cannot find a way to create the program to do so. When I create theRPG module it is not teraspace enabled. The ILE Concepts book says RPGILE is teraspace enabled but it isn't working. We are on V5R3.

Yes, RPG modules are teraspace enabled starting with V4R4. However, maybeI need to clarify what is meant by "teraspace enabled".

Teraspace enabled means that the RPG module is capable of working withteraspace pointers. You can allocate memory in teraspace by calling the_C_ts_malloc() API. You can perform pointer math on these teraspacepointers. You can dereference the pointer and copy data to/from theteraspace memory.


That's what "teraspace enabled" means.

In RPG, every module (V4R4 or later) is automatically teraspace enabled.You do not have to do anything special to make them so. In ILE C,however, you have to specify TERASPACE(*YES) to make a program teraspaceenabled.

Now, ILE C has a bunch of additional teraspace options that go above andbeyond the enablement of teraspace. It has an option called *TSIFC thattells the preprocessor to automatically substitute a call to_C_ts_malloc() instead of malloc(). Same for realloc(), cmalloc(), anfree() -- the teraspace equivalent is automatically substituted.

RPG does not have that option. It has to explicitly call the_C_ts_malloc() API (and friends) if it wants to use teraspace. The ALLOCop-code, or the %alloc() BIF will only allocated in single-level storage.

C also has an option called STGMDL(*TERASPACE), that lets it use teraspacefor EVERYTHING, not just when you deliberately allocate memory fromteraspace. The ILE Concepts manual refers to this as the "TeraspaceStorage Model", and states that it "goes beyond" normal teraspaceenablement. RPG does not have an equivalent option.

When you create a service program that uses STGMDL(*TERASPACE), it'll runin a teraspace activation group instead of a normal one. This can be aproblem if you specify ACTGRP(*CALLER) on the service program, becauseyou;re (presumably) calling it from an RPG program, and that RPG programcreates the activation group.

The RPG program will create a normal activation group. When it tries toload the C service program with ACTGRP(*CALLER), the activation will failwith MCH4430 (Activation access violation) because the C service programrequires a special teraspace activation group! But, again, this onlyhappens when the C module and service program are created withSTGMDL(*TERASPACE), and not for simple teraspace enablement.


If this is whats happening to you, there are a few ways to fix it:

a) Compile the C module and service program with the following settings:

       CRTCMOD TERASPACE(*YES *TSIFC) STGMDL(*INHERIT)
       CRTSRVPGM STGMDL(*INHERIT) ACTGRP(*CALLER)

   This tells the ILE environment to use a single-level storage model
   when called from an activation group that's designed for single-level
   storage, and a teraspace storage model when called from an
   activation group that's designed for teraspace.

   Calls to malloc() and friends will still allocate memory in teraspace,
   but any memory allocated by the system (instead of an explicit call
   to malloc/calloc/realloc) will depend on the activation group it's
   called from.

b) Continue using STGMDL(*TERASPACE), but do NOT specify ACTGRP(*CALLER).
   Instead, use a named activation group that's separate from the one
   that the RPG program is using.

c) Use STGMDL(*SNGLVL) throughout.  Only teraspace-enable your programs,
   do not use the teraspace storage model.

Hope that helps. If not, please provide more information about theproblem. I had to take a guess at what the problem was, since you saidthere was an error, but didn't say how the programs were created, or whatthe error was!