Re: Weird irreproducible error

[Enrico Colombini <erix@...>]

> It does read and write files. How would a disk indexer cause disk
> errors? That might be something I could do something about.

It shouldn't, but I think we've all sometimes seen strange behavior of 
all sorts in Windows. Especially with third-party software (e.g. 
antivirus updaters/scanners).
For example, anything hogging CPU or locking down a file long enough 
could possibily cause problems, but they're not too difficult to catch 
if you've at least minimal error handling in place on the Lua side.
I'm definitely not thinking of file-related problems as the most 
probable cause for what you're experiencing, but I mentioned it just in 
case.

Anyway, you can check for it by logging all file access from your 
program with a tool such as sysinternal's filemon (now "process 
monitor", I think) and checking the log file for errors when it happens.

First thing, though, would be to find a way to reproduce the problem, or 
at least reproduce it frequently enough for tests to make sense,by 
running the program continuously, possibly with (semi-)random data to 
see if some datasets are worse than others (remember to record or write 
out the random seed to be able to reproduce it). I just used this 
technique to find a nasty C++ bug of mine :-)
Then I'd do the interference test (shutting down all unneeded services 
and restarting them one by one at wide intervals), then the diskmon log 
check and the "clean Windows" VMWare check that has been suggested.

I forgot: if you're using temporary files, how did you create them?

  Enrico

P.S. Of course it *could* still be a pure Lua-application problem.