On Wednesday April 25 2007 8:42 am, Varjü Tamás wrote: > Dear Greg! > > The reason I did the test, and why I detailed the result is that I could > not reproduce any of the nasty things which can happen without locking. > I know that everyone suggests to use the lock, but following your > argument the test should have had a different outcome. > > Any idea how to improve the test to realise potential data loss? It > would convince me beyond "to be on the safe side". > > Kanya
you example I think features two processes accessing the same file , now a typical web application may have 2000 to 2 million processes going at the file at the same time ... example being some thing like a search engine. To test or produce a race condition or over writing , put the script under a real world load . fork 20 or thirty instances of your script at the same time and let them have a go at the file. then look at the results and see if it's what you think it should be. bet it won't be :) If you are certain that no more than 2 processes will ever access the file then feel free to forgo file locking . I have personal seen this happen with as little as three processes accessing the same file... There is a reason everyone suggest using file locking it's because we have all "been their and done that". it's a common mistake new programmers make. ask yourself "why do Data Base programs have row locking ? " it's the same thing. Greg -- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] http://learn.perl.org/
