A hand-me-down copy of ACM Queue has an article in it about "the Guru Code" which lambasts this allegedly poor behaviour by programmers. The author was a bit flustered by seeing
Fatal System Error
Guru Code: #0002000436; #0001000258
on his TV screen.
Certainly, it's bad for a member of the user public to be exposed to this stuff. But, consider the lot of the poor programmer: no confidence in design, no patience in re-work, desperation to get the demo out, the impending doom of managerial dictat to distribute the demo, the creep of featurism, tuning into the flood of complexity ...
Huge amounts of code gets written in a rush to trial it and then either sent out as finished work, or thrown away. There's no middle ground, many times. To respond, the embattled programmer evolves. Learning, hacking, proving, grand construction, re-construction, managerialism, revisionism, and hacking all over again.
As we travel this path from initiate to guru and back to code monkey, we develop techniques of survival. One of the most efficacious is what the article refers to as the Guru Code. This is an indecipherable number that is only interpretable by the person who wrote it. What this means is that a particular path of code that should never have happened has indeed happened.
Of course, the outsider can say, well, you should write better code. Nope, see above; the boss wouldn't let that happen. Or, at least, you should write better error messages. Which is what the article states.
Think about it for a bit. If the code should never have happened, that means that it wasn't going to be dealt with in code! What would the error message say? "Write me?" Or, perhaps, "tell my boss I told you so?"
In practice there are lots and lots - we are talking in the thousands here for any serious shipped product - of error conditions where there is nothing to say. Other than it happened right here, and that's something that should never have happened.
What I tend to do is put in a "numberplate" error code. This little innovation is a group of three letters and three digits: ABC123, chosen randomly by typing blind. Then, if it *ever* pops up in a user complaint or a log, it is recognisable as such. The only solution is to run a massive search of all source code looking for it, and go looking at the code (there is no support database for these things, because they never happen).
Of course, such a non-occurrance happens only once a year or so. Like the front cover of the magazine says, "System Errors Happen. Deal with it." When it does happen, it's really useful to see the code stick out like a sore thumb. From there, inspection of the code makes it clear, and we can make some minor fixes to get back to the normal state of affairs, which is that it will never ever happen (again). Promise.
Posted by iang at December 30, 2004 11:39 AM | TrackBack