Hi Stefan, It is the simplest method!
Thanks Stefan and all people replied on this thread. On Dec 8, 2007 6:23 PM, Stefan Kost <[EMAIL PROTECTED]> wrote: > Hi Ben, > > Ben Lau schrieb: > > hi all, > > > > I am implementing a GObject (a simple video player) that creates a > > GStreamer pipeline for video processing. Soon it receives a new > > GstBuffer of video frame from the pipeline, it will emit a signal. As > > GStreamer processes the pipeline with multiple threads. The signal > > handler may not be involved inside the main thread. If my GObject > > calls g_signal_emit() within the handler, then client's callback > > function may also not be involved from the main thread. > > > You should use the GstBus. In the signal handler create an application message > and post it to the bus. The bus will marshall data and invoke signal handler > in > you application thread. your app need to have signal handlers on the bus to > listen for the application message. > Here is an example: > http://buzztard.cvs.sourceforge.net/buzztard/buzztard/src/ui/edit/main-toolbar.c?view=markup > look for > on_channels_negotiated() > > Stefan > > > > > If the callback uses any Gdk/Gtk functions, then it may cause a race > > condition. Ofcoz it could be avoided by using > > gdk_threads_enter/gdk_threads_leave pair. However, I want to hide the > > multi-threading issue from user ,so that they don't need to care > > about. > > > > To achieve this purpose, the signal should be emitted within the main > > thread. Could anybody suggest a method to ensure that a signal is > > emitted within the main thread? > > > > I am thinking about to create a GSource to attach to the main > > context. Soon a new frame is ready, it will dispatch the event to my > > video player in main thread. But I wonder would it have any other > > simpler method to achieve the goal? > > > > Thanks for any advise. > > _______________________________________________ > > gtk-app-devel-list mailing list > > gtk-app-devel-list@gnome.org > > http://mail.gnome.org/mailman/listinfo/gtk-app-devel-list > > _______________________________________________ gtk-app-devel-list mailing list gtk-app-devel-list@gnome.org http://mail.gnome.org/mailman/listinfo/gtk-app-devel-list
