RE: Friendly co-existance

[furgalj@xxxxxxxxxxxxxxxx]

The Java 1.5 release has some of this as standard. It's called "Class Data 
Sharing." From the 1.5 Beta release notes:

"The class data sharing feature is aimed at reducing application startup 
time and footprint. The installation process loads a set of classes from 
the system jar file into a private, internal representation, then dumps 
that representation to a "shared archive" file. During subsequent JVM 
invocations, the shared archive is memory-mapped in, saving the cost of 
loading those classes and allowing much of the JVM's metadata for these 
classes to be shared among multiple JVM processes."

The real question is when IBM will have this ported over to the power PC 
64 architecture. Apple doesn't have it yet for their G5's either, so it's 
probably a ways off. Sun is planing 1.5 GA for this September for Intel 
architectures. One interesting note is that they WON'T offer this feature 
under Windows! Hmmm, I wonder why -).

The little bit I've played with it under Intel Linux is impressive. After 
the first couple of runs, your Java GUI apps start almost as fast as the 
C/GTK apps. On a run-of-the-mill IBM A31 Thinkpad, you only notice the 
startup difference if you really sit there and watch for it. It's probably 
around a 300 milli second difference. Very acceptable. It will be 
interesting to see what IBM does with this, as their JVM's are usually 
tweaked a little more for speed. 


Jeff Furgal