Someone on another non-windows perl list wrote this:
>Incidentally, I hate to call this stuff "memory leaks", since it's usually >just normal growth as memory gets used. Calling it "leaks" implies that >memory is being wasted as a result of mistakes with pointers or some such. >When people hear "memory leaks" they go running for stuff like Apache::Leak, >thinking they can find some problem and fix it, which is usually not the case. This prompts me to relate a recent experience and ask for comments. I have an application that runs on Windows with ActiveState Perl. It loops through a bunch of records and for each record it invokes LWP to fetch some data, parses the results, and saves some text in a file that grows with each iteration. With my small tests, everything went fine. When I delivered it to the customer, he tried it out and everything looked fine, until he tried it on a file with 3000 records. It died after the 450th with an Out of memory! error, and I was able to get an Out of memory! error on my box on the same file too. I looked into the source, thinking there was some reference count that wasn't going to zero and this was responsible for using it up. Not so. I used Win32::SystemInfo to show free memory available. I was surprised to see how much memory was consumed on each pass. By cutting out sections of code, I was able to see exactly what was consuming the memory. I found that LWP ate up a bunch, and substitutions ate up more. I'd never really worried about memory much before, and never had any problems on Linux where my perl software usually runs. In fact the very same program ran perfectly well on a Linux box with 1/4 the memory. During my tests on Windows, I found that up to 1 MB was being consumed each time through the loop! I found that my output results file was close to 1MB at this time. I was updating the results file by slurping the whole thing into memory, doing a substitution and writing it back out again. By changing it to read one line at a time, while writing to a different filehandle, the consumption dropped to almost zero. Okay, maybe my first method was wasteful, but I didn't expect the memory to be used just once! I was very surprised to see that when I finished with the memory (by it going out of scope, or being undefined, or set to ""), it wasn't being returned for re-use, but that's the way it worked. Is this just a Windows thing (Windows XP and ME)? Is this a normal thing that everyone always lives with? I've got routines on the Linux box that can run for weeks without running out of memory. Any comments? Mike Gossland _______________________________________________ Perl-Win32-Users mailing list [EMAIL PROTECTED] To unsubscribe: http://listserv.ActiveState.com/mailman/mysubs
