I just forgot to explain how to run the Dancer app. Probably easier to use this app: http://paste.perldancer.org/1nX0n7dg6abTJ
Also, the test with only DBI and no Dancer here: http://paste.perldancer.org/uzagWiCYXUsj that doesn't "leak" anything. mje_ on IRC did some experiments and found out that when using prepare_cached the scalar count doesn't change. But then, strange enough to have prepare leaking inside dancer, and not outside. :-| Cheers Alberto (aka ambs) On Tue, May 7, 2013 at 1:36 PM, Alberto Simões <hashas...@gmail.com> wrote: > Hello > > I am experiencing a behavior when using DBI inside Dancer that seems to > result on SCALAR leaks, but only when running inside Dancer. > > To help diagnosing I did a couple of tests that I try to explain below. > > First, I developed a sample small application in Dancer. It is available > (temporarily) in http://paste.perldancer.org/2yIABT6Yreh5T. Basically, it > has two routes. One that calls Devel::Gladiator and dumps the count for > each type of variables currently available, and another route that returns > OK. This route has a prepare statement (line 27) that is my problem. > > If I comment that line, and test calling the main route different times > (calling the arena between calls) I get the result in > http://paste.perldancer.org/sWhBrp2rh1lq. Basically, first 5 hits are > discarded, just to make sure all variables and caches prepared by Dancer > are filled in, and then I call the main route 100 times. You might notice > the amount of scalars rarely changes, and at the end, the summary is > negative (less two scalars than the amount we had when beginning the test). > > If I uncomment, then I get http://paste.perldancer.org/1mjhfOfwxEJxf, > where you might notice almost each call increments a SCALAR into memory. At > the end, the summary is 97 wasted scalars (almost the same number of hits). > > Although I imagine DBI does some kind of cache, it is weird it stores 97 > copies for the same query. Nevertheless, I tried a similar approach without > Dancer, and NO SCALAR gets lost at all. > > Also, tried to do, in the same route, two prepares, and the number of lost > scalars doubles. If I do only one prepare but two execute/fetch, I get only > one scalar lost. > > So, this is something about Dancer and DBI together. But I have no idea of > what might be going on. > > > If you need some more details, or that I run some test, please poke me at > #dbi on irc.perl.org (ambs). > > Thanks, > Alberto (aka ambs) > > -- > Alberto Simões > -- Alberto Simões
