On 30-Jun-08, at 12:15 PM, Igor Stasenko wrote:

> 2008/6/30 tim Rowledge <tim at rowledge.org>:
>> I am trying to make time to post a few articles on some future  
>> directions I
>> consider interesting for the core system.
>>
>> First one is up at http://people.squeakfoundation.org/article/ 
>> 89.html - do
>> please comment on the relevant page, or even here.
>>
>
> This is not the only things which i don't like.
> For instance look into ObjectMemory>>fetchClassOf:
> it fetching class depending on object header. Either from compact
> classes array (by index), or from slot, reserved for class reference.
> I think eliminating compact classes would simplify the access to
> object's class and free us some bits again: type mask bit (at least).
>
> It also will make fetching a class oop faster and uniform, so there
> will be no branching.
> Fetching a class from Compact classes array, requires:  getting oop at
> index in special objects array, and then getting oop from this object:
>
> class := fetchPointer: ccIndex - 1 ofObject: (self fetchPointer:
> CompactClasses ofObject: specialObjectsOop)
>
> A drawback of getting rid of compact classes is additional memory cost
> per each instance of classes which were compact.

Good points but perhaps for another thread?


tim
--
tim Rowledge; tim at rowledge.org; http://www.rowledge.org/tim
Every bug you find is the last one.