On Fri, Dec 11, 2009 at 5:56 PM, André Warnier <a...@ice-sa.com> wrote: > When you say "It (perl) will keep the memory", do you mean that > - the perl interpreter embedded in this Apache child will keep the memory > (and not return it to the OS), but will re-use it if possible for other > variable allocations happening within its lifetime ? > or > - the perl interpreter embedded in this Apache child will keep the memory > (and not return it to the OS), and never re-use it again for any other > variable allocation happening within its lifetime > (in other words, this is a leak) ?
Option 3: Perl will keep the memory and reuse it for that exact same lexical variable the next time you enter that section of code. It's a performance optimization that is usually a good thing, unless you put a lot of data in one lexical in some code that you rarely run. It's not a leak. Perl tracks the memory and will reuse it, just not for any other variables. > Does any guru care to provide some simple real-world examples of when memory > once allocated to a variable is/is not being re-used, in a mod_perl handler > context ? It's simple to see. Slurp a file into a lexical. Let it go out of scope. There are many posts on this subject in the archives here as well as on PerlMonks and the p5p archives. > Maybe on this last subject, what I gather from this and other discussions > I've seen, is that once the Perl interpreter obtained some memory from the > OS, it rarely returns it (before it exits); and if it does, it is in any > case not practically predictable in a cross-platform way, so one cannot rely > on it. Is that a fair interpretation ? Yes, you can't expect to get memory back. - Perrin
