--- robert burrell donkin <[EMAIL PROTECTED]> wrote: > i've commit the patch of the 15th (with a few minor > changes). thanks. > Great. Thanks much :)
> this means that the value is (effectively) held by a > hard reference > whilst the key is held by a weak. this should > address the narrow issue > of the most typical use case. i think that probably > the code could be > improved by eliminating some unnecessary complexity > but that'll have to > wait till tomorrow. Actually, I think it should work with the "commons-logging in WEB-INF/lib" case as well. In that use case, the relevant LogFactory and WeakHashtable are actually loaded by the webapp classloader, so they too are gc'ed when the webapp is undeployed. Attached is a patch to LogFactoryTest that I believe shows this. Please let me know if this is wrongheaded in some way -- I wouldn't be surprised at all if it is. I took some time to study what the existing LoadTest class does and tried to mimic it to test different classloading configurations. (In fact, if this patch is accepted down the road I should do a quick refactor to avoid duplication w/ LoadTest). The other day when I thought it wouldn't work in the WEB-INF/lib situation, my test classloader was delegating all loading to its parent EXCEPT LogFactoryImpl. LogFactory and everything else was loaded by the parent. That's not the same as putting commons-lib in WEB-INF/lib. The classloader in the attached patch is a more correct mock of a webapp classloader. My mistake the other day does show one area where WeakHashtable will fail -- if a custom subclass of LogFactory were deployed in WEB-INF/lib but commons-logging.jar were on the server classpath. But I expect that's a pretty small use case. Oh, BTW, the patch also removes the previous test of whether the LogFactory is eventually released once the classloader is released. Now it just tests if the classloader is released. Testing release of the LogFactory basically duplicated what was already done in WeakHashtableTest. > one interesting feature of garbage collectors (which > foxed me for a > while) is that there doesn't seem to be any > guarantee as to when the > reference is placed onto the queue. (at least i > can't find one: if > anyone knows different please jump in.) on the > (macOSX) JVM i use, it > appears that the reference is placed onto the queue > late enough to > cause one of the tests to fail. placing a hard loop > that polls for the > released reference to be placed on another queue > results in the test > passing... > Interesting. This whole thing's been interesting -- way more than I thought it would be when I started off grunting through a bunch of reflection :) Cheers, Brian > > On 16 Nov 2004, at 15:12, Brian Stansberry wrote: > > > Attached is a patch to LogFactory that attempts to > > play classloader tricks to prevent the hard > reference > > problem. This is not meant to be applied; the > patch > > is just a shorthand way to communicate ideas I'm > > playing with. > > P.S. Thanks to all for not laughing at this one! > > This seemed to work in the sense that the tests I > > added to LogFactoryTest pass. But, > o.a.c.l.LoadTest > > fails with a ClassCastException. Other tests in > that > > package pass. Haven't had time to try and analyze > > what's going on with the LoadTest. > > > > Gotta run to work. > > > > - brian > > > > > > > > __________________________________ > > Do you Yahoo!? > > The all-new My Yahoo! - Get yours free! > > http://my.yahoo.com > > > > > > > --------------------------------------------------------------------- > > To unsubscribe, e-mail: > [EMAIL PROTECTED] > > For additional commands, e-mail: > [EMAIL PROTECTED] > > > --------------------------------------------------------------------- > To unsubscribe, e-mail: > [EMAIL PROTECTED] > For additional commands, e-mail: > [EMAIL PROTECTED] > > __________________________________ Do you Yahoo!? The all-new My Yahoo! - Get yours free! http://my.yahoo.com
--------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
