[maemo-developers] Runtime exception in Multithreading N800

[From: Richard Pickler]

This little document got me through some rough nights when trying to
multithread my gtk app.

http://research.operationaldynamics.com/blogs/andrew/software/gnome-desktop/gtk-thread-awareness.html

Don't remember where I first came across it, but I owe that man a beer.

On Sun, Mar 23, 2008 at 6:54 AM, Chris Lord <chris at openedhand.com> wrote:
> On Sat, 2008-03-22 at 11:49 -0500, nisha jain wrote:
>  > Hi All,
>  >
>  > I have used pthread in my application and Hildon APIs for the GUI.
>  >
>  > In my application the main() is used for the GUI and pthread for
>  > communication.
>  >
>  > I am getting following run time exception some times while running
>  > number of times...
>  >
>  > Though i am not able to identify the cause...
>  >
>  >
>  > N800App[2455]: GLIB CRITICAL ** Gtk - gtk_box_pack_start: assertion
>  > `child->parent == NULL' failed
>  >
>  > Please let me know if some one has any idea about it?
>
>  You'd get this error when trying to pack a widget into a Gtk[VH]Box when
>  that widget is already contained (i.e. it has a parent). To re-pack a
>  widget, you need to g_object_ref it, (assuming you don't hold a
>  reference), remove it from its container (gtk_container_remove) and then
>  you'll be able to pack it into the box successfully (remember to unref
>  afterwards).
>
>  Also note, GTK is not thread-safe, so GTK functions mustn't be called
>  outside of the main thread. You can use gdk_threads_enter/leave, but
>  it's generally easier to use idle callbacks (if you g_idle_add in a
>  thread, the callback will happen in the thread of the mainloop, as
>  opposed to whatever thread you called it from).
>
>  Hope that helps!
>
>  --Chris
>
>
>
>
>
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