Re: Using (or not using) sigc::mem_fun with the G_CALLBACK macro

[Bob Caryl <bob fis-cal com>]

Lars Luthman wrote:

> On Thu, 2005-06-16 at 07:22 -0500, Bob Caryl wrote:
>  
>
> > I had originally intended to write my help display routine as part of a 
> > dynamic library intended for use by my applications.  If I use a global 
> > function in this setting it would be entirely possible that multiple 
> > applications and/or threads in the same application could try to call 
> > such a global function simultaneously (or nearly simultaneously), 
> > thereby giving indeterminate results.
> >    
>
> Why would a global function be less thread safe than a member function?
> As long as you're not using any global or static function variables
> (which you also could do in a member function) I don't see how there is
> a difference.
>
>  
I'm an old windows programmer (and therefore relatively new to linux GUI 
programming), and so I'm assuming that dynamically loaded libraries work 
the same way under linux as they do under windows:

If an application (or thread within an application) instantiates an 
object, it gets its own exclusive copy of that object (complete with all 
the data used by such an object).  If, on the other hand, an application 
(or thread), uses a global function and/or global data from within a 
dynamically loaded library that is subject to such use by other 
applications and/or threads, it is possible that simultaneous accesses 
could happen.  In the case of my callback, two applications could be 
trying to load data into the SAME GtkHTML widget at the same time and 
thereby would be sharing ONE GtkHTMLStream handle.

If my understanding of how dynamically loaded libraries work under 
linux, please disabuse me of my notions.