Re: C-function returns *NULL when executing malloc

On 16/09/2009, at 10:28 PM, Birgitta Hauser wrote:

In an specific environment it works the first time I call the procedure, but
for all subsequent calls MyDS_p is returned as *NULL-Value (and I have no
idea why, there is no joblog entry either ).

Only two documented reasons for malloc() to return NULL:
1) Insufficient storage available
2) Requested allocation size is zero

Reason 1 is possible but unlikely unless previous allocations are not being released (i.e., memory leak) especially on only the second call, reason 2 would also be unlikely because the code uses %SIZE to calculate the requested allocation however I think the compiler calculates the result of %SIZE once and stores it so perhaps the storage is being trashed and set to a nonsense value?

If I call the same procedure from an other program within the same job it
works without problems, even for repeated calls.

Suggests the problem is in the calling program.

I know it would be easier to define the data structure directly without
based, but it is an old procedure and I cannot change it.

Someone has an idea what happened.

My colleague assumes it is because I’m using named activation groups, while
all other programs and service program (also this one where the procedure is
located) run in the QILE default activation group.

Hmm, terminology check. QILE isn't the default activation group. There is no difference between the QILE activation group and any other named activation group.

But I cannot imagine that different activation groups may cause this
problem.

I doubt it too. Given what you describe I suspect the calling program is doing something to trash storage which results in this effect.

Regards,
Simon Coulter.
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