Re: Application suddenly stuck at startup

[Robert Schroll <rschroll gmail com>]

On Fri, Mar 1, 2013 at 10:12 AM, Jonathan Ballet <jon multani info> 
wrote:
> I notice that either:
>   * removing the loop with Gtk.main_iteration(), or...
>   * removing the "Gdk.threads_init()" call
> doesn't exhibit the problem.

I think the problem is that you don't have the Gdk lock when you're 
calling Gtk.main_iteration, which is a bad thing.  If you take out 
Gdk.threads_init, the main thread will never give up the lock, so your 
callback will be guaranteed to run inside of it.  If you don't need to 
do Gtk stuff from other threads, this is probably the way to go.

If you can't do that, then you have to make sure you have the Gdk lock 
when calling main_iteration:
    Gdk.threads_enter()
    try:
        while Gtk.events_pending():
            Gtk.main_iteration()
    finally:
        Gdk.threads_leave()
This works for me, at least.  You'll probably also need to do this in 
other callbacks that do Gtk stuff.

An aside: in pyGTK, you could do
    with gtk.gdk.lock():
Is there something equivalent in the pyGI universe?

N.B. This is all based on my incompletely understanding of GTK 
threading.  If someone else says I'm wrong, they're likely right.

Robert