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From André Warnier ...@ice-sa.com>
Subject Re: [OT] tomcat 5.5.25 shared lib and sharing webapp jars
Date Sat, 10 Oct 2009 21:41:52 GMT
Christopher Schultz wrote:
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> Chuck,
> 
> On 10/10/2009 9:26 AM, Caldarale, Charles R wrote:
>>> From: Christopher Schultz [mailto:chris@christopherschultz.net] 
>>> Subject: Re: [OT] tomcat 5.5.25 shared lib and sharing webapp jars
>>>
>>> My direct experience that had led me to believe that ClassLoaders 
>>> keep lists of their loaded Classes is that a WebappClassLoader
>>> held across a webapp restart (due to inadequate cleanup by the
>>> webapp) results in all Class objects loaded by that
>>> WebappClassLoader staying in memory, essentially forever.
>> I think you are correct about Tomcat's WebappClassLoader; it has to 
>> maintain the set of the classes it has loaded since it breaks the 
>> normal Java delegation rule, and can't simply ask its parent for the 
>> class.
> 
> Is that because the primordial ClassLoader will hand-out references to
> any class already loaded by any ClassLoader, so if null is returned,
> then the current ClassLoader knows it needs to do its own loading (if it
> can)?
> 
>> The JVM itself keeps track (outside of the heap) of all loaded
>> classes so that classloaders that follow the standard delegation rule
>> don't have to.
> 
> Also, the WebappClassLoader has to be able to re-load classes that are
> updated during runtime. In order to do that, it needs to know what has
> been loaded and when.
> 
Not that it was my thread to begin with, and not thjat it's really 
dramatic either, but I suppose you guys must realise that you lost me, 
like, about 15 posts ago ?
:-)


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