Re: [libcvd-members] gvars3 Makefile.in configure configure.ac gvars...

[Edward Rosten]

On Wed, 20 Feb 2008, Georg Klein wrote:

> On Wed, 20 Feb 2008, Edward Rosten wrote:
>
> > On Wed, 20 Feb 2008, Georg Klein wrote:
> >
> > > Nice.
> > >
> > > The whole global-initialised-in-a-library thing does seem rather unsafe 
> > > when other classes use it in a constructor!
> >
> > True. I don't know exactly what the best solution is. Something to do with 
> > singleton classes.
>
> GVars2 had no globals defined in the library, so that you could define them 
> in main.cc, in the order they need. Wherever they live, all inter-dependent 
> globals should live in one translation unit, and that's what you've done in 
> gvars3's inst.cc, but it doesn't work (portably) when I have other global 
> classes which call GUI in their constructors.

> A trivial fix would be a configure flag which excludes inst.cc from the 
> library. This would fix all of my problems. Unless you're on a configure 
> editing buzz, I'll get around to doing this some time soon.


Hm. I like having the classes  ready instantiated, since it cuts down on 
the code. I could go back to having ifdefs so that GVars instantiates 
everything in the same inst.cc file.

Also, you could generate a new .so library. One .so has all the code, but 
no instantiations. The other .so has the instantiations and points back to 
the .so with the code in.

> > Not to mention the entire thread safety thing...
> >
> > There's two solutions to that as far as I can see.
> >
> > One is to put locks around the whole GVars3 database.
> >
> > The other is to have all widgets sets operate using their own private 
> > string-tring map. Every so often, you will have to call a synchronize 
> > method which will synchronize the GVars database with the private map.
> >
> > The second version is nice because it keeps gvars fast and you know that in 
> > your main loop, things aren't going to change from under you.
>
> (Shrug)
> I don't use any of the widget sets!

Do you do everything in your OpenGL widget set these days?

I still use widget sets quite a lot. I've written some quite largeish GUIs 
that way...

> I suspect there's probably a lot of stuff 
> which no-one uses anymore in there. For example, IIRC headless was requested 
> by Ethan, but I think he uses his own thing now instead of gvars?

Oh. I actually put the headless stuff in there. I ocasionally need to run 
batch jobs on a cluster. It's pretty handy for that, since those machines 
frequently don't have GUI libraries installed, and I can use the same code 
for interactive and batch use.

-Ed