[Info-vax] QIO Writes to a mailbox

[Jose Baars]

Op 11/4/2011 5:52 PM, Steve Bainbridge schreef:
> On Nov 4, 2:46 pm, Steven Schweda<sms.antin... at gmail.com>  wrote:
> Whilst it's simple to change the code, replicating the problem has
> proved impossible and releasing into production onto many tens of
> systems takes a long time with a lot of effort

A bug can cause 2 things: immediate crash or undeterministic behaviour.
So there is a bug, and very likely it is in 'your' code.

If you follow Steven's suggestion to fix the obvious problems, you only have
to prove it works on a test system to have at  least the same code quality
as what you have now on production.

If it was my assignent, I wouldn't hesitate to ditch most everything of
the mailbox IO, and write it again, to avoid inheritance of other problems
in the old code.

Btw. these kinds of bugs are abundant in ancient (ex-VAX?) code where
these bugs were able to survive unnoticed thanks to (the lack of) speed
on these machines: you were often lucky. You might even have that 'luck'
now, unless your test systems are as fast as your production systems.
A very wide spread way of saving money in the nineties was to not order
manuals.