On Tue, 2005-11-29 at 19:42, Robert Cummings wrote: > On Tue, 2005-11-29 at 19:22, Adam Atlas wrote: > > So... I have this script (being called in a perfectly typical way by > > PHP 4.4.1 through mod_php in Apache 2.0.55) which sometimes runs > > perfectly, and sometimes chooses, totally haphazardly, to seemingly > > run itself twice, which of course causes it to die with a fatal error > > after it tries to redefine some functions. > > > > As mysterious as that is, it turns out it must be something > > altogether more sinister. I tried putting die() at the end of the > > script, on the assumption that it was for some reason executing > > twice, yet behold: the problem is still present, and the PHP error > > log still complains about constants and functions being redefined! > > The problem, I therefore thought, cannot be that the script is being > > run twice. (In retrospect, this was the most likely possibility, > > because the page doesn't actually output anything if it dies with > > this error.) So for debugging, I added a bit that logs one message to > > a file immediately before the die() at the end of the file, and a > > different message after the die(). The die() seems to be working > > normally, in that it only logs the first message... > > > > But wait a second! WTF? If the PHP error log is to be believed, then > > the script should be dying with a fatal error before it even *gets* > > to that point in the script, isn't it? > > > > And the greater WTF is the fact that, as I mentioned above, every > > time the page is requested, it unpredictably either does this or > > works flawlessly. Oh my. How do I even *begin* to debug something > > like this? > > I think you mean heisenbug... > > http://en.wikipedia.org/wiki/Heisenbug > http://en.wikipedia.org/wiki/Schr%C3%B6dinger%27s_cat Hmmm, you learn something new every day: http://en.wikipedia.org/wiki/Schroedinbug But the problem you're having seems better represented as a heisenbug :) Cheers, Rob. -- .------------------------------------------------------------. | InterJinn Application Framework - http://www.interjinn.com | :------------------------------------------------------------: | An application and templating framework for PHP. Boasting | | a powerful, scalable system for accessing system services | | such as forms, properties, sessions, and caches. InterJinn | | also provides an extremely flexible architecture for | | creating re-usable components quickly and easily. | `------------------------------------------------------------' -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php
