Re: Confusing about memory leak and GtkTreeView, GtkCellRendererCombo & GtkCellRendererSpin

[Yu Feng <rainwoodman gmail com>]

Hi Kim,

Usually if a property of a GObject is G_TYPE_OBJECT, the GObject will
hold a reference count of that property.

And because your GtkAdjustment is created in a floating state, you don't
need to unref it after setting it as a property value of a GObject.

refer to line 209:gtkcellrendererspin.c
   if (obj)
    priv->adjustment = g_object_ref_sink (obj);
      break;

and line 150:gtkcellrendererspin.c
  if (priv && priv->adjustment)
    g_object_unref (priv->adjustment);

> >       adj = GTK_ADJUSTMENT (gtk_adjustment_new (50.0, 0.0, 100.0, 5.0,
> 10.0, 0.0));

   adj->ref_count = unknown,
   adj->is_floating = true.

       renderer = gtk_cell_renderer_spin_new ();
   renderer->ref_count = unknown
   renderer->is_floating = true
> >
> >       g_object_set (renderer, "editable", TRUE, "adjustment", adj,
> "digits", 0, NULL);
> >
   renderer->ref_count = unknown
   renderer->is_floating = true
   adj->ref_count = 1
   adj->is_floating = -1


the remaining ref_count of adj shouldn't be freed by you. It will be
freed in  GObjectClass->dispose of renderer. (that's why that reference
is owned by renderer: who frees, who owns)

Yu

On Fri, 2008-12-12 at 14:10 +0900, Keedi Kim wrote:
> HI, :-)
> 
> Memory leak and reference counts are very confused.
> I am using GtkTreeView with GtkCellRendererCombo and GtkCellRenderSpin.
> So, I use Adjustment for GtkCellRendererSpin
> and GtkListStore(or GtkTreeStore) for GtkCellRenderCombo.
> 
> Some of columns uses same Adj, and TreeModel, so saved them in renderer.
> Rest of columns uses different so I saved them in GtkTreeModel and set
> attributes.
> 
> Anyway, I'm very confusing about memory management.
> 
> I have understood I have to decrease reference count to avoid memory leak
> when I use following API because they increase reference count:
> 
> g_object_set()
> gtk_tree_store_set()
> 
> Now I have some question about those API, and GtkCellRenderer{Combo|Spin}.
> 
> 1.
> If I use GtkCellRenderSpin and make new GtkAdjustment
> which is saved in the **Renderer**, then do I have to do g_object_unref(adj)
> ?
> 
> 2.
> If I use GtkCellRenderSpin and make new GtkAdjustment
> which is saved in the **GtkTreeModel** with setting attribute,
> then do I have to do g_object_unref(adj) ?
> 
> 3.
> If I use GtkCellRenderCombo and make new Gtk{Tree|List}Store
> which is saved in the **Renderer**, then do I have to do
> g_object_unref(model) ?
> 
> 4.
> If I use GtkCellRenderCombo and make new Gtk{Tree|List}Store
> which is saved in the **GtkTreeModel** with setting attribute,
> then do I have to do g_object_unref(adj) ?
> 
> 5.
> Is there any connection with floating issues?
> When I save GtkAdjustment in Renderer
> before saving, floating value is true
> and after saving floating value is false,
> But I save GtkAdjustment in GtkTreeModel,
> before saving, and after saving floating value is still true.
> 
> And here is some code snippets for asking this issues.
> 
> * code snippet which saves GtkAdjustment in Renderer
> code:
> >     {
> >       GtkAdjustment *adj;
> >       GtkCellRenderer *renderer;
> >       GtkTreeViewColumn *column;
> >
> >       adj = GTK_ADJUSTMENT (gtk_adjustment_new (50.0, 0.0, 100.0, 5.0,
> 10.0, 0.0));
> >       renderer = gtk_cell_renderer_spin_new ();
> >
> >         {
> >           gboolean colorness_float;
> >           colorness_float = g_object_is_floating (adj);
> >           g_debug ("=========> float: colorness(%d)\n", colorness_float);
> >         }
> >
> >       g_object_set (renderer, "editable", TRUE, "adjustment", adj,
> "digits", 0, NULL);
> >
> >         {
> >           gboolean colorness_float;
> >           colorness_float = g_object_is_floating (adj);
> >           g_debug ("=========> float: colorness(%d)\n", colorness_float);
> >         }
> >
> >       g_object_unref (adj); <----- /* DO I NEED THIS? */
> >
> >       g_signal_connect (G_OBJECT (renderer), "edited", G_CALLBACK
> (brightness_edited), window);
> >
> >       column = gtk_tree_view_column_new_with_attributes
> (_(column_titles[VIEW_CAMERA_BRIGHTNESS]),
> >                                                          renderer,
> >                                                          "text",
> MODEL_CAMERA_BRIGHTNESS,
> >                                                          "visible",
> MODEL_SUPPORT_CAMERA_PROPERTY,
> >                                                          "sensitive",
> MODEL_ONLINE,
> >                                                          NULL);
> >       gtk_tree_view_column_set_resizable (column, FALSE);
> >       gtk_tree_view_column_set_clickable (column, FALSE);
> >       gtk_tree_view_append_column (GTK_TREE_VIEW (tree_view), column);
> >     }
> 
> result:
> > =========> float: colorness(1)
> > =========> float: colorness(0)
> 
> * code snippet which saves GtkAdjustment and GtkListStore in GtkTreeModel.
> code:
> >     {
> >       GtkAdjustment *bitrate_adj, *gop_size_adj;
> >       GtkListStore *quality_model;
> >       gchar quality_str[1024];
> >
> >       bitrate_adj = GTK_ADJUSTMENT (gtk_adjustment_new (10.0, 10.0, 100.0,
> 10.0, 20.0, 0.0));
> >       gop_size_adj = GTK_ADJUSTMENT (gtk_adjustment_new (10.0, 10.0,
> 100.0, 10.0, 20.0, 0.0));
> >
> >       quality_model = gtk_list_store_new (2, G_TYPE_STRING, G_TYPE_INT);
> >         {
> >           GtkTreeIter combo_iter;
> >           gchar str[1024];
> >           gint value;
> >
> >           value = 1;
> >           g_snprintf (str, 1024, _("%d (Highest)"), value);
> >           g_strlcpy (quality_str, str, 1024);
> >           gtk_list_store_append (quality_model, &combo_iter);
> >           gtk_list_store_set (quality_model, &combo_iter, 0, str, 1,
> value, -1);
> >
> >           value = 2;
> >           g_snprintf (str, 1024, "%d", value);
> >           gtk_list_store_append (quality_model, &combo_iter);
> >           gtk_list_store_set (quality_model, &combo_iter, 0, str, 1,
> value, -1);
> >
> >           value = 3;
> >           g_snprintf (str, 1024, _("%d (Lowest)"), value);
> >           gtk_list_store_append (quality_model, &combo_iter);
> >           gtk_list_store_set (quality_model, &combo_iter, 0, str, 1,
> value, -1);
> >         }
> >
> >         {
> >           gboolean bitrate_float, gop_size_float, quality_float;
> >
> >           bitrate_float = g_object_is_floating (bitrate_adj);
> >           gop_size_float = g_object_is_floating (gop_size_adj);
> >           quality_float = g_object_is_floating (quality_model);
> >
> >           g_debug ("=========> float: bitrate(%d), gop_size(%d),
> quality(%d)\n", bitrate_float, gop_size_float, quality_float);
> >         }
> >
> >       g_object_ref_sink (bitrate_adj);
> >       g_object_ref_sink (gop_size_adj);
> >
> >       gtk_tree_store_set (GTK_TREE_STORE (model), iter,
> >                           MODEL_VIDEO_FRAME_RATE, 1,
> >                           MODEL_VIDEO_BITRATE, 10,
> >                           MODEL_VIDEO_GOP_SIZE, 10,
> >                           MODEL_VIDEO_QUALITY, 1,
> >                           MODEL_VIDEO_QUALITY_STRING, quality_str,
> >                           MODEL_VIDEO_BITRATE_ADJ, bitrate_adj,
> >                           MODEL_VIDEO_GOP_SIZE_ADJ, gop_size_adj,
> >                           MODEL_VIDEO_QUALITY_MODEL, quality_model,
> >                           -1);
> >         {
> >           gboolean bitrate_float, gop_size_float, quality_float;
> >
> >           bitrate_float = g_object_is_floating (bitrate_adj);
> >           gop_size_float = g_object_is_floating (gop_size_adj);
> >           quality_float = g_object_is_floating (quality_model);
> >
> >           g_debug ("=========> float: bitrate(%d), gop_size(%d),
> quality(%d)\n", bitrate_float, gop_size_float, quality_float);
> >         }
> >
> >       g_object_unref (bitrate_adj); <----- /* DO I NEED THIS? */
> >       g_object_unref (gop_size_adj); <----- /* DO I NEED THIS? */
> >       g_object_unref (quality_model); <----- /* DO I NEED THIS? */
> >     }
> 
> result:
> > =========> float: bitrate(1), gop_size(1), quality(0)
> > =========> float: bitrate(0), gop_size(0), quality(0)
> 
> 
> Any suggestions and help will be appreciated.
> Thanks, :-)
> 
> P.S.
> If there are documentations for this issues.
> Could you please recommand the url please?
>