dbus-c++: strange behavior when using gtkmm

[Jesús Ruiz de Infante]

[I started this thread on dbus-cplusplus-devel at lists.sourceforge.net but got no response,
sorry for the crossposting. Hope it's OK]

It seems that in dbus-c++ there is a problem when the glib main loop must attend a dbus
signal coming just after it called a dbus method. If that dbus signal handler tries to
emit a sigc signal, the sigc signal is actually never emitted (or at least, a slot
connected to it is never executed).

I have prepared the following scenario:

Actors:
- testserver: A server of a simple service, with a signal (_signal_mode_switched)
   and a method (handle_key_pressed_event). The handle_key_pressed_event() method
   just emits _signal_mode_switched.
- testclient 1 & testclient 2 : two identical clients of the service. These are gtk
   applications, where clicking in a button triggers a call to
   handle_key_pressed_event(), and receiving a _signal_mode_switched, triggers a sigc
   signal_mode_switched, which just changes a label in the application.

                                   test svc server
                           .------------------------------------.
                           |  .-------------------------------. |
                           |  | handle_key_pressed_event      | |
                     .------->|   dbus: _signal_mode_switched | |
                     |     |  |                               | |
                     |     |  '-------------------------------' |
                     |     |                  |                 |
                     |     '------------------|-----------------'
                     |                        |
                     |                        |
      .----------------------------.          |        .----------------------------.
      | sigc: signal_mode_switched |<----------------->| sigc: signal_mode_switched |
      |                            |                   |                            |
      |       .-------------------.|                   |      .-------------------. |
      |       |                   ||                   |      |                   | |
      |       | on_mode_switched: ||                   |      | on_mode_switched: | |
      |       |   change label    ||                   |      |   change label    | |
      |       '-------------------'|                   |      '-------------------' |
      |                            |                   |                            |
      '----------------------------'                   '----------------------------'
             test svc client 1                               test svc client 2


Assuming the following events:

- The user clicks on the single button of the first client, the client 1
   calls the handle_key_pressed_event dbus method of the server.
- Then the server emits the dbus _signal_mode_switched, which is
   received by both clients.
- On the clients, the _signal_mode_switched signal emits the sigc
   signal_mode_switched.
- on_mode_switched, which is connected to signal_mode_switched,
   should change the label on both clients.

The problem is, on_mode_switch is only called on the client that didn't
sent signal_mode_switched.

The result is the same independently of the number of clients.
All work as supposed except the one calling handle_key_pressed_event()
on the server.

I have attached some sample code.

System Info:
Centos 5.2

dbus-python-0.70-7.el5
dbus-1.0.0-7.el5
dbus-glib-0.70-5
dbus-glib-devel-0.70-5
dbus-devel-1.0.0-7.el5
dbus-x11-1.0.0-7.el5


pygtk2-2.10.1-12.el5
gtk2-engines-2.8.0-3.el5
pygtk2-libglade-2.10.1-12.el5
libgtk-java-2.8.7-3.el5
gtkspell-2.0.11-2.1
gtksourceview-1.8.0-1.fc6
gtk2-2.10.4-20.el5
gtk2-devel-2.10.4-20.el5
gtkhtml3-3.16.3-1.el5
gtk-doc-1.7-1.fc6
gtkhtml2-2.11.0-3
gtkmm24-2.10.10-1.el5
pygtk2-codegen-2.10.1-12.el5
usermode-gtk-1.88-3.el5.1
authconfig-gtk-5.3.21-3.el5
gtkmm24-devel-2.10.10-1.el5
gnome-python2-gtksourceview-2.16.0-2.el5
pygtk2-devel-2.10.1-12.el5

latest dbus-c++ from git repo

-- 
Mit freundlichen Grüßen

Jesus Ruiz de Infante
(Entwicklung)
HALE electronic GmbH
Eugen-Müller-Straße 18, 5020 Salzburg, Austria
Tel:  +43 (662) 439011 0
Fax:  +43 (662) 439011 9
jesus.ruizdeinfante at hale.at
Firmenbuchnummer: FN 66801m HG Salzburg


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