Re: Crashes using custom signals

[dexter <dexter balabit hu>]

Sorry, I forgot your main problem.

It seems that the error comes from the initialization of the _signal_a 
member. Try to change the order of the main_window, signal_a variable to 
this:

>>>     SignalTypeA _signal_a;
>>>     std::auto_ptr<MainWindow> _main_window;

So the _signal_a should be _before_ the _main_window.

> ----- Original Message -----
> From: "Phillip Neiswanger" <sigsegv0 gmail com>
> To: dexter <dexter balabit hu>
> Sent: Thu, Jan 15, 2009 10:53:34 AM +0100
> Subject: Crashes using custom signals
>
> Thanks.
>
> That solves the gtk warnings, but does not solve the core dump when 
> trying to connect() in the MainWindow constructor.
> --
> phil
>
>
> On Thu, 15 Jan 2009 02:06:22 -0700, dexter <dexter balabit hu> wrote:
>
> > Hi,
> >
> > I'm not sure, but I think you're missing the Gtk::Main initialization 
> > before creating the mainwindow. So this:
> >  > Application::Application()
> >  >     : _main_window(new MainWindow)
> >  > {
> >
> > should be something like this:
> >  > Application::Application(int &argc, char **&argv)
> >  >     : Gtk::Main(argc, argv), _main_window(new MainWindow)
> >  > {
> >
> >
> > > ----- Original Message -----
> > > From: "Phillip Neiswanger" <sigsegv0 gmail com>
> > > To: gtkmm-list gnome org
> > > Sent: Thu, Jan 15, 2009 3:02:13 AM +0100
> > > Subject: Crashes using custom signals
> > >  Hi,
> > >  At this end of this message is a simple test program. Note the 
> > > connect() call in the Application constructor. If I move the 
> > > connect() out of that constructor and into the MainWindow constructor 
> > > like so:
> > >  MainWindow::MainWindow()
> > > {
> > >     Application::instance()->
> > >         signal_a().
> > >            connect(sigc::mem_fun(*this, &MainWindow::on_a));
> > > }
> > >  I get a core dump in the connect() call. The back trace looks like 
> > > this:
> > >  (gdb) bt
> > > #0  0x48cfb89f in std::_List_node_base::hook () from 
> > > /usr/lib/libstdc++.so.5
> > > #1  0x48808501 in std::list<sigc::slot_base, 
> > > std::allocator<sigc::slot_base> >::insert () from 
> > > /usr/X11R6/lib/libglibmm-2.4.so.1
> > > #2  0x488292ff in sigc::internal::signal_impl::insert ()
> > >    from /usr/X11R6/lib/libsigc-2.0.so.0
> > > #3  0x48829343 in sigc::internal::signal_impl::connect ()
> > >    from /usr/X11R6/lib/libsigc-2.0.so.0
> > > #4  0x48829526 in sigc::signal_base::connect ()
> > >    from /usr/X11R6/lib/libsigc-2.0.so.0
> > > #5  0x0804ce7c in sigc::signal0<void, sigc::nil>::connect 
> > > (this=0xbfbfe7c0,
> > >     slot_= 0xbfbfe7e0) at signal.h:2655
> > > #6  0x0804c3fe in MainWindow (this=0x8092180) at t.cc:39
> > > #7  0x0804c96c in Application (this=0xbfbfe860) at t.cc:54
> > > #8  0x0804cc91 in main () at t.cc:82
> > >  Why? What's wrong with my code?
> > >  Here's the code:
> > >  #include <gtkmm/main.h>
> > > #include <gtkmm/window.h>
> > >  #include <memory>
> > > #include <iostream>
> > >  typedef sigc::signal<void> SignalTypeA;
> > >  class MainWindow;
> > >  class Application : public Gtk::Main
> > > {
> > >   public:
> > >     Application();
> > >    ~Application();
> > >      SignalTypeA signal_a();
> > >      static Application* instance();
> > >      void run();
> > >    private:
> > >     std::auto_ptr<MainWindow> _main_window;
> > >     SignalTypeA _signal_a;
> > > };
> > >  class MainWindow : public Gtk::Window
> > > {
> > >   public:
> > >     MainWindow();
> > >    ~MainWindow();
> > >      void on_a();
> > > };
> > >  MainWindow::MainWindow()
> > > {
> > > }
> > >  MainWindow::~MainWindow()
> > > {
> > > }
> > >  void
> > > MainWindow::on_a()
> > > {
> > > std::cout << "Test output" << std::endl;
> > > }
> > >  Application::Application()
> > >     : _main_window(new MainWindow)
> > > {
> > >     signal_a().connect(sigc::mem_fun(*_main_window, &MainWindow::on_a));
> > > }
> > >  Application::~Application()
> > > {
> > > }
> > >  SignalTypeA
> > > Application::signal_a()
> > > {
> > >     return _signal_a;
> > > }
> > >  Application*
> > > Application::instance()
> > > {
> > >     return dynamic_cast<Application*>(Gtk::Main::instance());
> > > }
> > >  void
> > > Application::run()
> > > {
> > >     Gtk::Main::run(*_main_window);
> > > }
> > >  int
> > > main()
> > > {
> > >     Application app;
> > >      app.run();
> > >      return 0;
> > > }
> > > _______________________________________________
> > > gtkmm-list mailing list
> > > gtkmm-list gnome org
> > > http://mail.gnome.org/mailman/listinfo/gtkmm-list