Problems with OSAPlugin in NON-Mac OSes

Juan Manuel Vuletich jmvuletich at sinectis.com.ar
Mon Oct 25 12:29:38 UTC 1999


Andrew,
I guess you are right. The primitive should fail without any error
message, and I'll modify that right now in the OS/2 VM.
In case the changeset you sent gets into the standard release image I
will put the error message again.
Thanks a lot.
Juan Manuel Vuletich


Andrew C. Greenberg wrote:
> 
> >Hi folks
> >I have almost ready the 2.6 VM for OS/2, but I'm having a problem and
> >need help.
> >The Applescript support is in the startUpList in the standard image.
> >This means that it tries to load TestOSAPlugin.dll when Squeak starts.
> >But this dll exists only for Mac. I'm getting an error message
> >complaining about this when I start Squeak. I don't like avoiding any
> >module loading error, and I don't want to need a special image for OS/2.
> >What is done about this in the other platforms?
> >Thanks
> >Juan Manuel Vuletich
> 
> As I understand it, the failure to load a plugin should not, by
> itself, result in any error messages.  (How else would Smalltalk be
> able to test for the presence of the plugin?).
> 
> I inferred these semantics, rightly or wrongly, by tracking the logic
> for handling pluggable primitives in the MacOS support code:  As
> understood, when
> 
>         <primitive: 'foo' module: 'bar'>
> 
> is executed, and it is the first execution of module 'bar,' and the
> .dll, shared library or other such thing is not found, the primitive
> should simply fail without an error message, leaving the calling
> method to determine how to respond in the "follow up" Smalltalk code.
> 
> Thus, at least on the MacOS VM, the existing code startUp for
> Applescript checks for the plugin and does nothing quietly if it is
> not present.  (The absence of the TestOSAPlugin in the system release
> is not a machine-dependent feature -- even for MacOS systems, the
> plugin must be installed before Applescript will work.  Nevertheless,
> the system reports no error if the TestOSAPlugin is not present)  I
> have confirmed this by running the standard image both with and
> without the TestOSAPlugin shared library.
> 
> Precisely what error messages are you getting?
> 
> In any case, the attached changeset provides a workaround providing a
> release function for Applescript, and includes a postscript releasing
> Applescript from the startUp.  I am not certain whether the problem
> described above, however, is a problem arising from Applescript, or a
> bug in the OS/2 plugin mechanics, in which case the changeset need
> not be incorporated into the general release.
> 
> If it is not an OS/2 issue, and I have simply misunderstood how
> plugins are supposed to work, the changeset can be added to the
> release and we'll simply advise those who want to use the plugin to
> initialize first (It's primary advantage for the moment is as an
> example how to use the new plugin compiler).  If so, I'll revise
> Applescript to be more system-sensitive, once I understand from where
> the problem has arisen.
> 
>                                     Name: Applescript2.24Oct521pm.cs
>    Applescript2.24Oct521pm.cs       Type: unspecified type (application/octet-stream)
>                                 Encoding: base64





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