Re: How to set stack size of main task?

[kilgallen@eisner.decus.org (Larry Kilgallen)]

In article <325608E8.C1B@ghgcorp.com>, Stanley Allen <sallen@ghgcorp.com> writes:
> Larry Kilgallen wrote:
>> 
>> On VMS, the main stack will "expand" when it runs out, although as
>> with any well-behaved operating system there are limits on how much
>> virtual memory can be spent in this endeavor (preventing an individual
>> user from filling the pagefile, for example).
>> 
> Have you checked this?  I made a simple recursive main program for
> DEC Ada on VMS about 7 years ago (yes, I know that's ancient history),
> which had no terminating condition -- infinitely recursive.  This
> was a test of just this feature.

I am sure there are limits, but the limits are set by your local
system administrators, and it is possible for them to allow you
more virtual memory than the pagefile can support.

> Apparently I did fill up the page file because the system crashed
> for an hour or two.  I remember that I was working for {company X},
> it was about 11:00am and the big VAX machine had about 80 users...

With that duration of outage, it was probably a "hang" rather than
a crash.  A "hang" is characterized by system administrators scratching
their heads while users wait.  A "crash" is characterized by system
administrators scratching their heads while users go on working since
the system has rebooted.

> I don't think the system administrators ever knew it was my fault...
> I kept my mouth shut... deleted the library....

There is plenty of evidence as to who was using all the pagefile
space, but a system administrator who did not have the quotas set
properly in the first place might not be skilled enough to read
the evidence.  A system administrator who _was_ skilled enough
to read the evidence would probably be too embarrassed about
having the quotas set wrong to discuss it with a mere user :-)

Bottom line, a well-designed, well-managed operating system
can insulate others from your infinite stack appetite and
serve you well for your merely outrageous stack appetite.
If either the well-designed or well-managed condition is not met,
you the individual have an opportunity to demonstrate it,
just as with the rocket discussions.

Larry Kilgallen