I don't know where RPG allocates storage from (you said "from the default heap which has 1 16M limit"), but I just ran a test that indicates RPG dynamic storage is not limited to only 1 16 megabyte piece of storage.

Below is the code and it had no problems allocating 16,000,000 bytes to each of 50 pointers.

Am I missing or misunderstanding something?

Did you mean to say 16M per pointer?

Mel Rothman
Mel Rothman, Inc.

D ptrs            s               *   dim(50)
D i               s             10i 0
C                   for       i = 1 to %elem(ptrs)
C                   alloc     16000000      ptrs(i)
C                   endfor
C                   eval      *inlr = *on

Jon Paris wrote:
 >> But what I'd really like to know - is there any reason for OS/400 to
return NULL after calling for example r = (char *) malloc(1000000) ;

The major reason would be that you've exhausted the heap space (or at least
there no contiguous space of 1,000,000 bytes available).  I'm not certain
about C, but RPG allocates form the default heap which has 1 16M limit.
Unless you specify that the C code is to use terraspace capability then I
suspect it has the same limit.  If you are using small amounts of memory I
wouldn't bother about it - if you're using 1,000,000 byte requests then
probably safer to use the CEE APIs and create your own custom heap.

Jon Paris


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