Is readonly file mapping a purpose of this project?

[Rémi Forax]

Le 05/03/2010 12:18, Ramón García a écrit :
> No, you did not understand my request .Class data sharing is limited
> to system classes.

No, CDS is controlled by a file named classlist in jre/lib.
You can change it and regenerate a CDS image
with -Xshare:dump

>   I am asking a module to be a file that can be
> distributed, and efficiently memory mapped and therefore shared.
>    

The module architecture enables that kind of optimisations ;
another one is Ahead Of Time compilation ;
but you need time to implement them.

> Android has a similar feature
> http://www.youtube.com/watch?v=ptjedOZEXPM
>    

Rémi

> On Thu, Mar 4, 2010 at 10:38 PM, Rémi Forax<forax at univ-mlv.fr>  wrote:
>    
>> Le 04/03/2010 16:34, Ramón García a écrit :
>>      
>>> It would save memory if the Java virtual machine were able to load a
>>> module file by mmap-ing it readonly and finding the Java class objects
>>> in it. In this way, several virtual machine instances using the same
>>> libraries would share memory. Is this among the features planned for
>>> this project?
>>>
>>>        
>> This is a feature of SUN jdk5 :)
>> http://java.sun.com/j2se/1.5.0/docs/guide/vm/class-data-sharing.html
>>
>> Rémi
>>
>>
>>