You modify your label from a thread that is not the main/ui thread. Gtk+ is not threadsafe (few exceptions). Use g_idle_add/ g_timeout_add/ and friends (those are threadsafe) to implicitly serialize your ui modifications into the gtk mainloop.
Do not use GDK_THREADS_ENTER/LEAVE foo unless you are maintaining a legacy codebase and you know exactly what this means including its implications. Best Bernhard On Nov 26, 2014 9:02 AM, "Sergei Naumov" <vo...@rambler.ru> wrote: > Hi! > > I am writing an application that periodically reads data from network > sockets > (from Modbus enabled devices actually) and displays them in GTK+ > application. I > read some tutorials about GTK threads and created a separate thread that > encompasses Modbus reads and updates to GTK labels: > > modbus_thread = g_thread_new ("update_from_modbus",update_ > from_modbus,NULL); > > The update_from_modbus() has a bunch of socket reads (inside > xantrex_read_value()) > and gtk_label_set_text() > > sprintf(params_val_text,"%-5.1f (%4.1f Hz)\n%-4.1f\n%-4d", > 0.001*xantrex_read_value(modbus_pointer,0x004C,RECONSTRUCT_YES), > 0.01*xantrex_read_value(modbus_pointer,0x004E,RECONSTRUCT_YES), > 0.001*xantrex_read_value(modbus_pointer,0x0054,RECONSTRUCT_YES), > xantrex_read_value(modbus_pointer,0x0052,RECONSTRUCT_YES)); > gtk_label_set_text (GTK_LABEL(ac1_params_val),params_val_text); > gtk_label_set_justify(GTK_LABEL(ac1_params_val),GTK_JUSTIFY_LEFT); > > However after several hours I see crashes when the program tries to > reconnect to > my device. I tried to enclose GTK operations into gtk_threads_enter() / > gtk_threads_leave() but it has no effect. Can anyone, please explain what > is > wrong here or may be point to a good example of multithreaded GTK code > which has > network socket operations in it? > > Thanks in advance, > > -- Sergei > _______________________________________________ > gtk-app-devel-list mailing list > gtk-app-devel-list@gnome.org > https://mail.gnome.org/mailman/listinfo/gtk-app-devel-list > _______________________________________________ gtk-app-devel-list mailing list gtk-app-devel-list@gnome.org https://mail.gnome.org/mailman/listinfo/gtk-app-devel-list