[Vm-dev] [squeak-dev] 64 bit FFI (was: porting Croquet to Squeak6.0 alpha...)

[Nicolas Cellier]

Hi Marcel,
no idea...
Look at timestamp:
eem 2/16/2016 12:42 · accessing · 2 implementors · only in change set
FFI-Kernel-EstebanLorenzano.45  ·
So presumably Eliot added that.

Le jeu. 28 mai 2020 à 17:00, marcel.taeumel <Marcel.Taeumel at hpi.de> a
écrit :

>
> Hi Nicolas,
>
> what is the role of ExternalStructure class >> #pointerSize then?
>
> Best,
> Marcel
>
>
> Nicolas Cellier wrote
> > Hi all,
> > beware of FFI 'long' and 'ulong'.
> > They are currently meaning (32 bits) int and unsigned int!
> > This dates back from the 80s when there were still odd OS with segmented
> > memory and 16-bits int.
> > long was thought as a safe int32_t at that time... and still means just
> > that in current FFI.
> >
> > I'd like to replace them with 'int' and 'uint', but we need to ensure
> > backward compatibility etc...
> >
> > FFI has ExternalType signedLongLong or just 'longlong' and ExternalType
> > unsignedLongLong or 'ulonglong' which are 64 bits on all architectures.
> > See implementors of #initializeAtomicTypes #initializeFFIConstants
> >
> > If you want a type that can hold a pointer on both 32 and 64bits arch,
> > then
> > it's doable with a FFI type alias
> > For example I have things like this in HDF5 module
> > Notice the single #(fieldName fieldType) which defines an alias, while
> > ordinary FFI struct gets an array of #(fieldName fieldType)
> > (and replace Size_t with Intptr_t if the purpose is hodling a pointer,
> > otherwise the ayatollahs of C standard will lash you)
> >
> > ExternalStructure subclass: #'Size_t'
> >     instanceVariableNames: ''
> >     classVariableNames: ''
> >     poolDictionaries: ''
> >     category: 'HDF5-External-atomic'
> >
> > Size_t class >>fields
> >     "Size_t defineFields"
> >     ^Smalltalk wordSize = 4
> >         ifTrue: [#( value 'ulong')]
> >         ifFalse: [#( value 'ulonglong')]
> >
> > However the "fields" must be re-generated when platform changes...
> > I tried to automate that sometimes ago, see:
> >
> > ExternalStructure class>>install
> >      "Resuming the image on another architecture may require a
> > re-compilation of structure layout."
> >      | newPlatform |
> >      newPlatform := Smalltalk platformName.
> >      PreviousPlatform = newPlatform
> >          ifFalse:
> >              [self recompileStructures.
> >             PreviousPlatform := newPlatform]
> >
> > It works if you switch from Win64 to MacOS64 for example...
> > However, this mechanism is not used yet at time of code loading, so
> > importing code generated on a different platform won't automatically
> > update
> > the structures (or alias) - the FFI package has no mechanism for that
> > (maybe we could add a hook in MC?).
> >
> > Le mer. 11 mars 2020 à 23:58, Bert Freudenberg <
>
> > bert@
>
> > > a
> > écrit :
> >
> >> I'd suggest to get OpenGL working outside of Croquet first:
> >>
> >> http://www.squeaksource.com/CroquetGL.html
> >>
> >> Step 1: Verify this works in 32 bits. (assuming you are doing this on
> >> Linux, you can run 32 bit Squeak side-by-side with the 64 bit one)
> >> Step 2: Make it work in 64 bits.
> >>
> >> The second step requires that you understand how FFI works, and how it
> >> handles e.g. pointers and integer sizes.
> >> I am assuming we do have a working 64 bit FFI, at least for x86_64
> >> machines.
> >>
> >> E.g. the OGLUnix>>glExtGetProcAddress: method returns a pointer. On a 32
> >> bit system, that fits into a 'ulong' which is 32 bits. On a 64 bit
> >> system,
> >> a pointer is 64 bits wide so it would not fit into a 32 bit word. Now I
> >> don't know how many bits 'ulong' has in our 64 bit FFI, but that
> >> declaration may have to change. Etc. pp.
> >>
> >> If you have questions about FFI then those are best directed at the
> >> vm-dev
> >> list since it is dealing with VM-level interfaces. CC'ing, please follow
> >> up
> >> there.
> >>
> >> - Bert -
> >>
> >> On Wed, Mar 11, 2020 at 2:54 PM gettimothy via Squeak-dev <
> >>
>
> > squeak-dev at .squeakfoundation
>
> >> wrote:
> >>
> >>> Okey dokey,
> >>>
> >>> Poking along, there is a stray glyph in OGLUnix openGLLibraryName after
> >>>
> >>> openGLLibraryName
> >>> ^Smalltalk osVersion = 'linux'
> >>> ifTrue: ['libGL.so.1']
> >>> ifFalse: ['GL']
> >>>
> >>> I removed it in my install and got past that error.
> >>>
> >>> Working exclusively with Croquet(Master)...
> >>>
> >>>
> >>>
> >>> My next error is in OGLUnixX11LE(OpenGL)>>glMatrixMode:
> >>>
> >>> glMatrixMode: mode
> >>> "This method was automatically generated."
> >>> "void glMatrixMode(GLenum mode);"
> >>>
> > <apicall: void 'glMatrixMode' (ulong) module: '#openGLLibraryName'>
> >>> ^self externalCallFailed
> >>>
> >>> The
> > <apicall:...>
> >  fails
> >>>
> >>> How to think about this?
> >>>
> >>> Is Croquet behind OpenGL latest?
> >>> Would teaching myself OpenGL programming be of use to the Croquet
> >>> project?
> >>>
> >>> cheers,
> >>>
> >>> tty
> >>>
> >>>
> >>>
> >>
>
>
>
>
>
> --
> Sent from: http://forum.world.st/Squeak-VM-f104410.html
>
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