Re: Pointer to int and vice versa

["Mark S. Waterbury" <mark.s.waterbury@xxxxxxxxxxxxx>]

Mihael:

ILE RPG IV does not support the use of __PTR64 pointers (aka. "short 
pointers").  So, you would need to create a thin layer or jacket or 
wrapper set of functions that takes care of marshaling the pointers back 
and forth, accepting __PTR128 pointers from RPG IV, and then converting 
them into __PTR64 pointers, and vice versa. There are some restrictions 
-- the contents of the __PTR128 must be a pointer into teraspace 
storage, and not a single level storage address, or it cannot be 
converted into a __PTR64 short pointer.

Assuming your library creates (allocates) any "objects" (or dynamically 
allocated data structures) pointed to by these short pointers, you could 
just return any such pointers to RPG IV (via the thin wrapper layer) as 
64-bit integers, assuming the RPG IV code would never attempt to 
directly use or de-reference such pointers, but would just call other 
functions or procedures, passing these short pointers as parameters, to 
act upon whatever-it-is that is pointed to by these "opaque" pointers. 
(This is akin to using "handles" instead of pointers, and is a common 
"best practice" technique used when writing libraries, to encapsulate 
private data structures, for "information hiding" purposes.)

Does that help at all?

Mark

> On 12/3/2010 9:25 AM, Schmidt, Mihael wrote:
> I am trying to build a serviceprogram with ILE C modules so that the functions/procedures are accessable from RPG.