Re: Mac OS X + PARI + FLTK

[Justin Walker <justin@mac.com>]

On Monday, November 10, 2003, at 11:49 PM, Justin C. Walker wrote:

> On Sunday, November 9, 2003, at 09:05 PM, Justin C. Walker wrote:
>
> > A quick update:
> >
> > On Friday, November 7, 2003, at 10:46 AM, Karim BELABAS wrote:
> >
> > > Hi,
> > >
> > >   I have ported gp hi-res graphics to the MacOS X platform, using the
> > > lightweight fltk library (www.fltk.org). Provided, fltk is installed,
> > > this is enabled by
> > >
> > >     Configure --with-fltk
> > >
> > > There are two problems:
> [snip]
> > I don't see run-away CPU activity when I execute the above (the CPU 
> > meter is pegged somewhere near the bottom), and I get a prompt back 
> > right away (independent of whether I terminate with a ';').
>
> I spoke too soon on this one.  While my first attempts did not show 
> any extraneous CPU activity, at some point later, I did get a child 
> process of gp taking off on its own.  I will have to do a little more 
> spade work to figure this out.

OK, a little searching through the archives helped here.

I believe (and will verify) that what you are trying to do is not 
possible on Mac OS X.  Specifically, if you use any Mac OS X frameworks 
above the BSD level (such as, oh, say, Carbon), you have a problem 
using 'fork()' in the usual Unix style.  The issue involves the Mach 
underpinnings of the system, and the reasons become deeply technical, 
but:
  the Mach components of a process (task) don't always play well with 
Unix-style operation, and in particular, forking can cause Mach 
resources to become unavailable.  The upper layers assume they are 
available and therefore, we have a conflict.  You can read about the 
details in the 'darwin-development' archives should you be interested 
(search for the thread "open fails in daemon" for one such discussion; 
others are in there too).

I will talk with the "pros from Dover" to see what can be reasonably 
done.  Karim, if you can mail me off-list with a synopsis of what you 
did to port this support to Mac OS X, that will help (I see the code, 
of course, but since I have a history of "GUI rejection", the code 
won't necessarily tell all).

Regards,

Justin

--
Justin C. Walker, Curmudgeon-At-Large  *
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