Hi Annick,

On Mon, Sep 29, 2014 at 5:30 AM, Annick Fron <list at afceurope.com> wrote:

> Hi,
>
>
> I have recently made some experiments with pharo and FFI, and I have ran
> into problems with callbacks.
> I am using linux 32 bits.
> First question : when calling a dynamic  library is it necessary that it
> exports all symbols ? What if symbols are noted « U » (undefined) ?
>

If you have undefined symbols in an external library, they need to be
resoled by the VM or other libraries loaded in the system.  If any are not
resolved the library will fail to load.


> 2) On one of my callbacks got the message « callback failed to own the VM
> » . Have you any idea of where it comes from ?
>

Yes.  This means you're trying to callback from a different thread than the
VM thread.  hat isn't supported yet.


> 3) If the callback is called  in a different thread, is it a problem ?
>

Yes.

4) On Pharo I have an error on the following : is it incorrect ? It is a 64
> bits problem ?
> Using FFI Linux examples.
>
> testGetOurWindowLocation
> "self new testGetOurWindowLocation"
>
> | display ourWindow aParent anX anY aWidth aHeight aBorderWidth aDepth |
> display := X11Display XOpenDisplay: nil.
> ourWindow := display ourWindow.
> (Alien lookup: 'XGetGeometry' inLibrary: 'X11')
>     primFFICallResult: nil
>     withArguments:
>         {display.
>         ourWindow.
>         (aParent := Alien new: 4).
>         (anX := Alien new: 4).
>         (anY := Alien new: 4).
>         (aWidth := Alien new: 4).
>         (aHeight := Alien new: 4).
>         (aBorderWidth := Alien new: 4).
>         (aDepth := Alien new: 4)}.
> (anX unsignedLongAt: 1) inspect
>

What's the error you get?

Annick
> Le 28 sept. 2014 à 21:44, David T. Lewis <lewis at mail.msen.com> a écrit :
>
> > On Sun, Sep 28, 2014 at 09:04:59AM -0400, David T. Lewis wrote:
> >>
> >> On Sun, Sep 28, 2014 at 11:19:30AM +0200, Nicolai Hess wrote:
> >>> Who is the maintainer of the FFI-Package for
> >>> Squeak and/or Pharo ?
> >>> I especially interested in the FFI-Unix examples
> >>> and the state on working FFI on linux for current squeak release
> >>> (AFAIK it does not work with "squeak all in one" 4.5)
> >>>
> >>
> >> The FFI package, including the FFI-Unix examples that you mention, is at
> >> http://source.squeak.org/FFI.
> >>
> >> The primary author was Andreas Raab. Eliot Miranda is the most recent
> >> contributor, and he is probably the most knowledgeable in this area.
> >> Currently, the Squeak core developers (those with commit rights to
> Squeak
> >> trunk) have commit rights to the FFI project, and can make updates as
> needed.
> >>
> >> The FFI examples for Unix work with the old FFI plugin, which is still
> >> present in the interpreter VM. The active development of Squeak FFI is
> >> taking place in Cog, and I'm not sure if the old FFI examples work with
> >> the newer plugins (which would be present in the Squeak all-in-one).
> >> The FFI plugin in the interpreter VM (i.e. trunk VMMaker) needs to be
> >> updated, and presumably the FFI examples may need some updates as well.
> >
> > A small but important correction: For the old plugin (currently in the
> > interpreter VM), FFI works only for a 32-bit VM. It also works for a
> 64-bit
> > VM, but only if the patches in http://bugs.squeak.org/view.php?id=7237
> have
> > been applied (in other words, if you compiled it yourself and included
> > those patches).
> >
> > This is mainly of historical interest, although it is possible that some
> > of the 64-bit patches will prove helpful for the newer FFI plugin. But
> > the emphasis now should be on Eliot's more recent FFI work.
> >
> > Dave
> >
> >
>
>
>


-- 
best,
Eliot
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