Hi,
I did find the following bullet points in the white paper very amusing. It appears that Sun has discovered that the following tricks, in addition to its admittedly way-cool dynamic profiling and adaptive optimizing, can lead to improved peformance in a VM:
(*) Handle-less pointers;
(*) Shorter (two-word) object handles;
I found there is a sentense on the white paper: "only arrays have a third header field, for the array size."
(*) Generational, copying compacting garbage collection, which they repeatedly characterize as "pauseless;" and
The algorithm is also called as "mark-compact algorithm".
More and more I read the white paper, it reminds me the design and implementation of Squeak (and Self, of course).
<<YOU GOTTA LOVE THIS!>>
(*) Reflective Data (Classes, MetaClasses and Methods) are now represented as first-class objects to facilitate a simpler object memory model and faster garbage collection.
I think the biggest difference is the way for management of "Contexts." HotSpot VM uses native machine's stack for the performance and possible parallel execution, though it may be the source of memory leaks:-)
OHSHIMA Yoshiki Dept. of Mathematical and Computing Sciences Tokyo Institute of Technology
Wow... seems like this is a first... I never saw Squeak on Freshmeat before.
For those that don't know, Freshmeat.net is a news announcer for new Linux binaries. Kinda like Slashdot.org, but for binaries only.
So Squeak 2.4 trying to go mainstream now huh?
-- Dino
squeak-dev@lists.squeakfoundation.org