Gdk-3.0 ▶ Gdk ▶ threads_add_idleSince 2.12

Adds a function to be called whenever there are no higher priority events pending. If the function returns false it is automatically removed from the list of event sources and will not be called again.

This variant of g_idle_add_full() calls function with the GDK lock held. It can be thought of a MT-safe version for GTK+ widgets for the following use case, where you have to worry about idle_callback() running in thread A and accessing self after it has been finalized in thread B:

static gboolean
idle_callback (gpointer data)
{
   // `gdk_threads_enter()`; would be needed for `g_idle_add()`

   SomeWidget *self = data;
   // do stuff with self

   self->idle_id = 0;

   // `gdk_threads_leave()`; would be needed for `g_idle_add()`
   return FALSE;
}

static void
some_widget_do_stuff_later (SomeWidget *self)
{
   self->idle_id = gdk_threads_add_idle (idle_callback, self)
   // using `g_idle_add()` here would require thread protection in the callback
}

static void
some_widget_finalize (GObject *object)
{
   SomeWidget *self = SOME_WIDGET (object);
   if (self->idle_id)
     g_source_remove (self->idle_id);
   G_OBJECT_CLASS (parent_class)->finalize (object);
}
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