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From Egor Pasko <egor.pa...@gmail.com>
Subject Re: Feedback on JRELite efforts
Date Sat, 22 Mar 2008 19:52:22 GMT
On the 0x40F day of Apache Harmony Johnny Kewl wrote:
> Thought you would be interested to know that our efforts to turn J2SE
> into a "click and go" Java failed miserably :)
> 
> I think that any JRE that sets up for speed "immediately" will never be lite.
> It loads everything under the sun, in an effort to be instantly fast.
> I think its still possible but not with "that" machine.
> 
> I been digging around trying to find good articles on JVM design so I can understand
the 
> design parameters. Anyone know of good links, please yell.
> 
> Even been doing things like simulating Java's dependencies, so I can see what an application
> "actually needs".
> Did some very rough analysis on a simple AWT app against sun J2SE...
> ie analysed dependencies, then wrote some software to extract every class "actually used".
> And the idea seems to pan out... for example from the one test I did the classes used
> came to around 1600... is that unbelievable or what (a simple app)... 
> .... BUT compressed its 2 megs ... and that aint bad at all.
> 
> I see there are a frew JSR's in this area so people are thinking about it, but they seem
> to be wrongly approaching it from a package view, installer view, not what the JRE is
actually needing.
> ie there is a big difference between thinking XERCES and XALAN package, and what the
JRE actually takes
> from it... the yada blah conversation that we already had... ie the JRE as installer
blah blah.
> 
> I think this is beeeeeg, and I see you have student projects on the go, I think a **
JRE Engine analyser **
> (if not done already) would be an amazing project.
> IE, show the analyser an application... it tells you, all the JRE classes used, the size,
the native component, and lists the dependency diags.
> The way I did it was very primative and very slow... but its an interesting area.

Yes, interesting.
This is a part of GSoC harmony-tools-1 idea (BundleTool)

There is a proprietary ahead-of-time compiler to produce small native
execuables limited to only the classes used. Examples of several such
applications:

http://www.excelsior-usa.com/java-download-size.html

In short: GUI <10MB, noGUI <5MB.

AFAIR, you would not call those packages lite. Given that the whole
JRE is about 20MB download ..

-- 
Egor Pasko


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