Re: Is RPG 'DEAD"

On 19/06/2008, at 3:23 AM, Paul Tuohy wrote:

I have no problem with explaining what you mean but you can't re- define
existing terms to satisfy your requirements. There is absolutely no
connection between a memory leak and freeing storage.

Much as I think Steve is so wrong so often there is no point discussing anything with him in this case he's not redefining terms: A memory leak is storage that is not freed when it should have been.

A memory leak is where a program overwrites memory to which it should not
have access. Worse case scenario being where it overwrites runnable code in
memory (as happened or earlier versions of Windows but happens a lot less
now)

No, that's a buffer overrun--also a direct consequence of C (and derivative languages) having no concept of a fixed-length variables.

Freeing storage is returning storage that the program determines is no
longer required.

True, but neglecting to free such storage is a memory leak.

Absolutely no connection between the two except that they both relate to
memory.

Might want to reconsider that statement in light of the above.

D buffer S *
C EVAL buffer = %ALLOC( 16776704 );
C SETON LR

is a memory leak. The leaked or lost memory will persist until the job ends or the activation group is reclaimed. This is, of course, significantly better than on other platforms where such storage is not recovered even when the process terminates. An IPL is the only option on such systems.

Lest anyone thing so-called "managed code" is immune to such problems it's not--it's just less susceptible than C etc. Truly immune languages probably don't exists but are more likely found amongst those with compiler support for fixed-length variables such as RPG, COBOL, and PL/1. Oh dear, all those archaic languages with inherent advantages over the "modern" stuff.


Regards,
Simon Coulter.
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