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Date: Thu, 12 May 2005 07:38:08 +0200
From: Reinhard Poetz <reinhard@apache.org>
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To: dev@cocoon.apache.org
Subject: Re: Continuation invalidation strategy
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Torsten Curdt wrote:
>>Looks like you're descibing current functionality :)
> 
> 
> ...well, then everything is ok! :-D
> 
> But seriously: I tried to explain why you cannot
> remove the parent continuation :-)

some experiments showed me that it is possible to remove parent continuations in 
flowscript. But profiling revealed that the benefit is negligible because 
continuaitons are very small objects. As said, the referenced objects are the 
problem as every new continuation tree references new objects  in the case an 
object is stored in a local variable.

I don't have a solution for this as I can't find a general rule when a tree can 
be invalidated, except after some time-out.

> One optimization we could add is a maximum
> continuations per session count. Like a sliding
> window. So we don't rely on a fix expiration
> time but additionally expire the oldest ones if
> we run over a certain amount of continuations
> per user.
> 
> That would make the memory consumption a bit more
> manageable.

hmmm, I'm not sure if this really helps as only if the *whole* continautions 
tree (= when the last continuation is invalidated) referenced objects can be 
removed by the garbage collector.

-- 
Reinhard P�tz           Independent Consultant, Trainer & (IT)-Coach 

{Software Engineering, Open Source, Web Applications, Apache Cocoon}

                                        web(log): http://www.poetz.cc
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