Libguestfs - Sep 2022 - another GTK3 regression...

On Fri, Sep 30, 2022 at 08:55:02AM +0100, Daniel P. Berrang?
wrote:
> On Thu, Sep 29, 2022 at 07:12:15PM +0100, Richard W.M. Jones wrote:
> > On Thu, Sep 29, 2022 at 04:47:34PM +0200, Laszlo Ersek wrote:
> > >
http://lacos.interhost.hu/livecd-p2v-202209291608-gitc213ae00a337.iso
> > > 
> > > (built at c213ae00a337)
> > > 
> > > sha256:
f3a149aeab0179213d74bb1eac30d5d6f807d4c9cf3a548667903d5434d5699a
> > 
> > No spinner!
> 
> BTW, is there any possibility your code is invoking GTK3 APIs
> from a thread != main GTK event loop thread ?  If so, that is
> a sure way to get non-deterministic wierd behaviour with GTK.
Maybe?  This is the code which is run when the "Test Connection"
button is clicked:

https://github.com/libguestfs/virt-p2v/blob/c213ae00a337cb04e63cbfe4fb4b3af4c003918f/gui.c#L404

It runs a thread (to test the connection using ssh) and that thread
creates an idle {job? event?} in the new thread.

However I documented it as:

 * Idle task called from C<test_connection_thread> (but run on the
 * main thread) to start the spinner in the connection dialog.

Whether that is true or not and how I deduced that, I don't recall.

Rich.

> > While I remember, an annoying virt-p2v bug is that the keymap is
> > always set to the US locale (try XTerm -> localctl status).  I
wonder
> > if it's easy to add a way to change the keyboard layout?  In
> > particular it doesn't work well if your password contains some
> > punctuation character which is mapped differently on US vs local
> > keyboards.
> 
> Assuming GTK3, you can use gsettings to change layout for apps
> 
> gsettings set org.gnome.desktop.input-sources sources
"[('"xkb"','"us"'),('"xkb"','"fr"'),('"xkb"','"it"')]"
> gsettings set org.gnome.desktop.input-sources current 1
> 
> this can be done dynamically on the fly too
> 
> With regards,
> Daniel
> -- 
> |: https://berrange.com      -o-    https://www.flickr.com/photos/dberrange
:|
> |: https://libvirt.org         -o-            https://fstop138.berrange.com
:|
> |: https://entangle-photo.org    -o-    https://www.instagram.com/dberrange
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-- 
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
Read my programming and virtualization blog: http://rwmj.wordpress.com
virt-p2v converts physical machines to virtual machines.  Boot with a
live CD or over the network (PXE) and turn machines into KVM guests.
http://libguestfs.org/virt-v2v

On Fri, Sep 30, 2022 at 09:41:02AM +0100, Richard W.M. Jones
wrote:
> On Fri, Sep 30, 2022 at 08:55:02AM +0100, Daniel P. Berrang? wrote:
> > On Thu, Sep 29, 2022 at 07:12:15PM +0100, Richard W.M. Jones wrote:
> > > On Thu, Sep 29, 2022 at 04:47:34PM +0200, Laszlo Ersek wrote:
> > > >
http://lacos.interhost.hu/livecd-p2v-202209291608-gitc213ae00a337.iso
> > > > 
> > > > (built at c213ae00a337)
> > > > 
> > > > sha256:
f3a149aeab0179213d74bb1eac30d5d6f807d4c9cf3a548667903d5434d5699a
> > > 
> > > No spinner!
> > 
> > BTW, is there any possibility your code is invoking GTK3 APIs
> > from a thread != main GTK event loop thread ?  If so, that is
> > a sure way to get non-deterministic wierd behaviour with GTK.
> 
> Maybe?  This is the code which is run when the "Test Connection"
> button is clicked:
> 
>
https://github.com/libguestfs/virt-p2v/blob/c213ae00a337cb04e63cbfe4fb4b3af4c003918f/gui.c#L404
> 
> It runs a thread (to test the connection using ssh) and that thread
> creates an idle {job? event?} in the new thread.
> 
> However I documented it as:
> 
>  * Idle task called from C<test_connection_thread> (but run on the
>  * main thread) to start the spinner in the connection dialog.
> 
> Whether that is true or not and how I deduced that, I don't recall.
The test_connection_thread code is using  g_idle_add to run all
GTK APIs, which results in it running in the main event loop
thread. That is the correct way to deal with GTK from multiple
threads.

As an idea to debug it more, try using the GTK inspector

   $ GTK_DEBUG=interactive <app binary>

this will popup a second window, which lets you browse the
widget hierarchy, view properties, etc. This might let you
see something that's set in an incorrect way.


With regards,
Daniel
-- 
|: https://berrange.com      -o-    https://www.flickr.com/photos/dberrange :|
|: https://libvirt.org         -o-            https://fstop138.berrange.com :|
|: https://entangle-photo.org    -o-    https://www.instagram.com/dberrange :|