[jdom-interest] Thread questions regarding JDOM SAXBuiler?
d.wall at computer.org
Wed Sep 1 08:36:07 PDT 2004
That's really interesting, though it also appears you've set some GC
arguments as well (I'm not familiar with them). But the GC did sound like
it might be a problem, though in the end, they both should have created the
same large XML document objects that would then be discarded. But this
continues to show 'reuse==true' creates a performance hit. Why have an
option that appears to slow things down, and even the javadocs indicate it
would slow things down. What's the purported benefit of doing reuse==true?
----- Original Message -----
From: "Laurent Bihanic" <laurent.bihanic at atosorigin.com>
To: "Per Norrman" <per.norrman at austers.se>
Cc: "David Wall" <d.wall at computer.org>; <jdom-interest at jdom.org>
Sent: Wednesday, September 01, 2004 7:54 AM
Subject: Re: [jdom-interest] Thread questions regarding JDOM SAXBuiler?
> I don't think your test tool performs enough iterations for the result to
> reliable due to garbage collector side-effects.
> I modified your tool to run 1000 iterations instead of 20 :
> java -XX:+AggressiveHeap large.ThreadedReader
> Reuse=true size=21837 time: 42497
> Reuse=false size=21837 time: 40796
> Reuse=true size=1927 time: 3403
> Reuse=false size=1927 time: 11125
> Reuse=true size=21837 time: 28469
> Reuse=false size=21837 time: 35527
> Reuse=true size=43469 time: 57238
> Reuse=false size=43469 time: 63963
> Reuse=true size=325632 time: 428557
> Reuse=false size=325632 time: 443638
> Per Norrman wrote:
> > Hi,
> > I meant to make the program self-cotained but missed the dependency
> > on the concurrent jar. Here's a new version. You should run the test
> > in your environment to confirm the results.
> > Yes, documents are discarded after being built. There are many
> > you can do in a test like this. My guess is that it's
> > handling in SAXBuilder and/or Xerces that accounts for the resuts.
> > A typical output in my environment (P3, 850Mhz, Dell Latitude C600):
> > Reuse=true size=21731 time: 5720
> > Reuse=false size=21731 time: 2215
> > Reuse=true size=1918 time: 200
> > Reuse=false size=1918 time: 300
> > Reuse=true size=21731 time: 1200
> > Reuse=false size=21731 time: 2065
> > Reuse=true size=43259 time: 3697
> > Reuse=false size=43259 time: 2663
> > Reuse=true size=324070 time: 25435
> > Reuse=false size=324070 time: 22233
> > Reuse=true size=756109 time: 66417
> > Reuse=false size=756109 time: 53194
> > The first run should be disregarded. Used for warming-up.
> > /pmn
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