Re: Using QRPLOBJ Library

On 06-Jul-2010 06:52, Charles Wilt wrote:

I could be mistaken, but IIRC there were some problems with some
of the larger shops using up permanent addresses with lots of
create / deletes; which required a reload of the LIC/OS(?) to
recover from.

That of course didn't go over well, and IBM ended up making some
changes in a v5 release somewhere that as I understand it allow
for permanent addresses to be cleaned up for reuse at IPL.

Again, I could very well be mistaken...


On Mon, Jul 5, 2010 at 2:51 AM, CRPence wrote:

(well the "not reused" is not completely true anymore; but
it used to be and for most purposes you can still consider it
to be true.)

<<SNIP>>

I am not sure to what "'not reused' is not completely true
anymore" alludes.?

I recall there was a change to effect a massive increase in the available permanent addresses. I do not recall if that was with RISC or a change since\on a newer RISC version.

And while I believe that there was also a means made available to reclaim used permanent addresses in order to avoid a scratch install of a system to recover, I am very skeptical the feature is part of any normal IPL. I only recall a /service procedure/ to effect that on systems in dire need. Perhaps instead of having whatever IBM support action was performed to activate the reclaim of permanent addresses, the IPL code runs such a cleanup automatically under some specific conditions; perhaps only after the SRC for no permanent addresses available.?

IMO any such reclaim activity would have to be a very *rare* event, because there are potential negative and totally unpredictable consequences for the OS code. If by some dark magic [i.e. the OS is not aware that the LIC storage management has reincarnated some of its stored-but-destroyed pointers] a stored pointer may suddenly appear instead to be a valid object, there is no predicting what OS code might do. Of course that the "object" only allows the supported methods would limit most improper accesses does give some peace-of-mind, but any "space" [object] can be written to... or worse. Because the effects can not be predicted is what makes the rarity of any such reclaim imperative; depending on the improbability of negative effects would be a poor design assumption.

Regards, Chuck