Marcel Weiher wrote:
> 
> I found the follwing info/hype on Sun's HotSpot compiler/system:
> 
> Fast Synchronisation
> 
>  - software only
>  - extremely fast
>     - up to 50x faster than others

The cost of a synchronzied call in Java with
todays VM seems to be at least 5 times slower
than a non synchronized call. 

>  - virtuall no per-object space overhead
>     - only 2 bits per object

The synchronizing feature in Java is special language
feature supported by the VM. The same mechanism can be easily 
implement in pure Smalltalk. Some time ago there was a free
package doing exactly that for Visualworks. 

Maybe HotSpot will answer us the question whether it makes
sense to implement this in the VM or not. 

>  - supports native threads, SMP
> 

More and more Java VM's support native threads. 
I wonder if all the Java classes are thread safe. 
What about Swing for example ?

> Anyone know more about it?
> 
HotSpot has been delayed more than once already. I'm
curious when it will come out finally. 
It seems to be a retargetable VM mostly written in C++. 
A port to HP-UX for example seems to be in work. 


Markus
-- 
Markus Kohler  mailto:markus_kohler at hp.com