Re: Program Interrupts (signals)
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Bob, ? I would argue that you need to make sure you clean up the environment.. The problem is that REXX in in fact part of the Nucleus and probably needs to re-initialise after a HX. How do later CMSs with NUCXLOAD handle this? Do NUCLEUS extensions know HX has occurred? ? Dave ?
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From: [email protected] <[email protected]> On Behalf Of Bob Bolch
Sent: 26 April 2020 11:33
To: [email protected]
Subject: Re: [h390-vm] Program Interrupts (signals)? I very much disagree with the idea that HX be trappable.? It's intent is to stop something immediately. Exits could continue causing more harm in their attempt to 'clean up' things, or to ignore the command to stop. Program checks and abnormal terminations are programming or environmental errors and are appropriately trappable. HI is a request to stop in an orderly fashion. HX is a command to cease and desist right now. ? On Sun, Apr 26, 2020 at 3:55 AM adriansutherland67 <adrian@...> wrote: Mark, Dave, Rob, Peter et al
I am sorry - I was clumsy and irritating.
My essay was not a criticism of what was done back in the day on CMS but rather it was a message was that things are kind of random and other past decisions would have changed the present (well maybe - but that is where we get into economics and Asimov Foundation territory).? OS has exit functions, and IBM introduced a native version into CMS with ABNEXIT (I have no idea if it traps HX but it should) - and the reason is that applications need this facility. Perhaps the DB2 team got a bit irritated as the plug kept being pulled from their software by operating systems, trashing database transactions. Who knows.
And I still think that if by random chance ABNEXIT had existed on VM/370, then when REXX was being implemented on it they would have used HX to do what they added HI to do. Rene can even check this! And you know what, IBM then might have been obliged to implement a non-maskable immediate called IC ("IPL CMS").?
This is all called?Counterfactual History. And actually this platform (VM/370) is an amazing opportunity to do practical counterfactual IT experiments. I cut my teeth on mainframes and am sad that (in my view) IBM "threw it all away"; is there a historical path that today would see IBM technology retaining is monopoly (and would that be a good thing)???
And Mark, I listen - and to be fair, one days debate to come to the conclusion that an exit function isn't going to exist on this VM/370 is not so long.?
I have had some experience across many platforms and languages - I can assure you that what I suggest is literally only what I have seen in other places and not just the ravings of a lunatic. The best outcomes come from open minded debates between people with different backgrounds - but we all know that.
Adrian
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