[Vm-dev] Alien initialization

[Tobias Pape]

Hi Eliot

> On 23.02.2018, at 23:36, Eliot Miranda <eliot.miranda at gmail.com> wrote:
> 
> Hi Tobias,
> 
>     done.  

thankyouverymuch

> I've made it match Alien class>>ensureInSpecialObjectsArray and so it only looks in VMObjectIndices.  But this should be OK right?

I think so. 
I just wanted to install a current VMMaker and it bailed all the way.
So I decided that I have no clue what's going on and proposed a fix that only added and did not remove a thing.

Best regards
	-Tobias

> 
> On Fri, Feb 23, 2018 at 11:45 AM, Tobias Pape <Das.Linux at gmx.de> wrote:
> 
> Hi,
> 
> can someone with commit rights on Alien please change the following method?
> 
> 
> UnsafeAlien class>>ensureInSpecialObjectsArray
>         "UnsafeAlien must be in the specialObjectsArray to enable the Newsqueak FFI.
>          Because of the bootstrap the specialObjectsArray may already have been
>          partially initialized with the callback selector and to be large enough (as part of
>          loading immutability), but it will be missing UnsafeAlien until UnsafeAlien is loaded.
>          So check if the specialObjectsArray is of the expected size before recreating
>          and slam UnsafeAlien in if the specialObjectsArray is already large enough."
> 
>         | index |
>         self ~~ UnsafeAlien ifTrue: [^self].
> 
>         index := 55.
>         (((Smalltalk includesKey: #VMObjectIndices)
>          and: [((Smalltalk at: #VMObjectIndices) classPool at: #ClassUnsafeAlien ifAbsent: []) == (index - 1)])
>         or: [
>                 ((Smalltalk includesKey: #ObjectMemory)
>                  and: [((Smalltalk at: #ObjectMemory) classPool at: #ClassUnsafeAlien ifAbsent: []) == (index - 1)])])
>         ifFalse:
>                         [self error: 'index probably wrong'].
> 
>         Smalltalk specialObjectsArray size < index ifTrue:
>                 [Smalltalk recreateSpecialObjectsArray].
> 
>         (Smalltalk specialObjectsArray size < index
>          or: [(Smalltalk specialObjectsArray at: index) ~~ nil
>                 and: [(Smalltalk specialObjectsArray at: index) ~~ self]]) ifTrue:
>                 [self error: 'SystemDictionary>>recreateSpecialObjectsArray appears incompatible'].
> 
>         (Smalltalk specialObjectsArray at: index) == nil ifTrue:
>                 [Smalltalk specialObjectsArray at: index put: self]
> 
> 
> This is necessary as in the current spur architecture the #Class.... class variables are no longer in ObjectMemory but in a Shared Pool.
> 
> Hence, it breaks on loading.
> 
> 
> Best regards
>         -Tobias
> 
> 
> 
> -- 
> _,,,^..^,,,_
> best, Eliot