Discussion :

[Kazujoshi]

Bonjour à tous,

Pour comprendre comment utiliser Valgrind/Memcheck, j'ai pris ce petit programme qui ne fait rien sauf afficher un GtkTreeView dans une fenêtre.

Code :

Sélectionner tout - Visualiser dans une fenêtre à part

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#include <gtk/gtk.h>
 
#define UI_FILE "/home/kazujoshi/test_treeview/test.ui"
 
void create_treeview (GtkBuilder *builder)
{
	GtkWidget *treeview =
		(GtkWidget *) gtk_builder_get_object (builder, "treeview1");
	GtkCellRenderer *renderer;
	GtkTreeViewColumn *id, *name;
	GtkTreeViewColumn *day[31];
	GtkListStore *store;
 
	store = gtk_list_store_new (33,
		G_TYPE_STRING, G_TYPE_STRING, G_TYPE_STRING, G_TYPE_STRING,
		G_TYPE_STRING, G_TYPE_STRING, G_TYPE_STRING, G_TYPE_STRING,
		G_TYPE_STRING, G_TYPE_STRING, G_TYPE_STRING, G_TYPE_STRING,
		G_TYPE_STRING, G_TYPE_STRING, G_TYPE_STRING, G_TYPE_STRING,
		G_TYPE_STRING, G_TYPE_STRING, G_TYPE_STRING, G_TYPE_STRING,
		G_TYPE_STRING, G_TYPE_STRING, G_TYPE_STRING, G_TYPE_STRING,
		G_TYPE_STRING, G_TYPE_STRING, G_TYPE_STRING, G_TYPE_STRING,
		G_TYPE_STRING, G_TYPE_STRING, G_TYPE_STRING, G_TYPE_INT,
		G_TYPE_INT);
	renderer = gtk_cell_renderer_text_new ();
 
	id = gtk_tree_view_column_new_with_attributes ("id",
		renderer,
		"text",
		0,
		NULL);
 
	name = gtk_tree_view_column_new_with_attributes ("name",
	renderer,
	"text",
	1,
	NULL);
	gtk_tree_view_append_column (GTK_TREE_VIEW (treeview), name);
 
	gint i;
	gchar *title = NULL;
	for (i = 0; i < 31; i++) {
		title = g_strdup_printf (" %i ", i+1);
		day[i] = gtk_tree_view_column_new_with_attributes (title,
			renderer,
			"text",
			i+2,
			NULL);
		gtk_tree_view_append_column (GTK_TREE_VIEW (treeview), day[i]);
		g_free (title);
	}
 
	gtk_tree_view_set_model (GTK_TREE_VIEW(treeview), GTK_TREE_MODEL(store));
	gtk_tree_view_set_rules_hint (GTK_TREE_VIEW(treeview), TRUE);
	g_object_unref (store);
	}
 
GtkWidget *create_window ()
{
	GError *error = NULL;
 
	GtkBuilder *builder = gtk_builder_new ();
	if (!gtk_builder_add_from_file (builder, UI_FILE, &error))
	{
		g_warning ("Couldn't load builder file : %s", error->message);
		g_error_free (error);
	}
 
	GtkWidget *main_window =
		(GtkWidget *) gtk_builder_get_object (builder, "window");
	g_signal_connect (G_OBJECT (main_window),
		"destroy", gtk_main_quit, NULL);
 
	create_treeview (builder);
 
	return main_window;
}
 
int main (int argc, char *argv[])
{
	GtkWidget *window;
 
	gtk_set_locale ();
	gtk_init (&argc, &argv);
 
	window = create_window ();
	gtk_widget_show (window);
 
	gtk_main ();
 
	return 0;
}

Le fichier text.ui est créé avec Glade :

Code :

Sélectionner tout - Visualiser dans une fenêtre à part

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<?xml version="1.0"?>
<interface>
  <requires lib="gtk+" version="2.16"/>
  <!-- interface-naming-policy project-wide -->
  <object class="GtkWindow" id="window">
    <property name="default_width">440</property>
    <property name="default_height">250</property>
    <child>
      <object class="GtkTreeView" id="treeview1">
        <property name="visible">True</property>
        <property name="can_focus">True</property>
      </object>
    </child>
  </object>
</interface>

J'utilise Valgrind en faisant :

G_SLICE=always-malloc G_DEBUG=gc-friendly libtool --mode=execute valgrind --tool=memcheck --leak-check=full --show-reachable=yes --leak-resolution=high --num-callers=20 --log-file=vgdump_test /home/kazujoshi/test_treeview/test

Le log retourné est très long donc je ne vais pas tout poster mais juste quelques lignes se rapportant à mes questions. Tout d'abord, voici le bilan :

==2135== LEAK SUMMARY:
==2135== definitely lost: 1,352 bytes in 7 blocks
==2135== indirectly lost: 4,636 bytes in 202 blocks
==2135== possibly lost: 12,243 bytes in 376 blocks
==2135== still reachable: 449,547 bytes in 6,608 blocks
==2135== suppressed: 0 bytes in 0 blocks
==2135==
==2135== For counts of detected and suppressed errors, rerun with: -v
==2135== ERROR SUMMARY: 201 errors from 201 contexts (suppressed: 132 from 13)

Je ne comprends pas comment éviter les erreurs relatives au GtkBuilder :

==2135== 740 (36 direct, 704 indirect) bytes in 1 blocks are definitely lost in loss record 4,074 of 4,171
==2135== at 0x4023F50: malloc (vg_replace_malloc.c:236)
==2135== by 0x484CED3: g_malloc (in /lib/libglib-2.0.so.0.2400.1)
==2135== by 0x4862AB8: g_slice_alloc (in /lib/libglib-2.0.so.0.2400.1)
==2135== by 0x4862DB4: g_slice_alloc0 (in /lib/libglib-2.0.so.0.2400.1)
==2135== by 0x47E45C6: g_type_create_instance (in /usr/lib/libgobject-2.0.so.0.2400.1)
==2135== by 0x47C8907: ??? (in /usr/lib/libgobject-2.0.so.0.2400.1)
==2135== by 0x47CA079: g_object_newv (in /usr/lib/libgobject-2.0.so.0.2400.1)
==2135== by 0x47CA937: g_object_new (in /usr/lib/libgobject-2.0.so.0.2400.1)
==2135== by 0x413E8B6: gtk_builder_new (in /usr/lib/libgtk-x11-2.0.so.0.2000.1)
==2135== by 0x8048EBC: create_window (main.c:63)
==2135== by 0x8048F9C: main (main.c:87)

Est-ce qu'une erreur de ce style est de mon ressort ? Valgrind renvoie pas mal d'erreurs relatives à des fonctions que je n'ai pas écrites, à pango, au xml, etc.

==2135== 160 (40 direct, 120 indirect) bytes in 1 blocks are definitely lost in loss record 3,924 of 4,171
==2135== at 0x4023F50: malloc (vg_replace_malloc.c:236)
==2135== by 0x49C7A03: nss_parse_service_list (nsswitch.c:622)
==2135== by 0x49C8146: __nss_database_lookup (nsswitch.c:164)
==2135== by 0x4030EAB: ???
==2135== by 0x4031F84: ???
==2135== by 0x49815A4: getpwnam_r@@GLIBC_2.1.2 (getXXbyYY_r.c:253)
==2135== by 0x487956D: ??? (in /lib/libglib-2.0.so.0.2400.1)
==2135== by 0x487B55C: g_get_home_dir (in /lib/libglib-2.0.so.0.2400.1)
==2135== by 0x424C217: ??? (in /usr/lib/libgtk-x11-2.0.so.0.2000.1)
==2135== by 0x424E8EA: ??? (in /usr/lib/libgtk-x11-2.0.so.0.2000.1)
==2135== by 0x41FA714: ??? (in /usr/lib/libgtk-x11-2.0.so.0.2000.1)
==2135== by 0x485378E: g_option_context_parse (in /lib/libglib-2.0.so.0.2400.1)
==2135== by 0x41FA30B: gtk_parse_args (in /usr/lib/libgtk-x11-2.0.so.0.2000.1)
==2135== by 0x41FA383: gtk_init_check (in /usr/lib/libgtk-x11-2.0.so.0.2000.1)
==2135== by 0x41FA3C3: gtk_init (in /usr/lib/libgtk-x11-2.0.so.0.2000.1)
==2135== by 0x8048F97: main (main.c:85)

Et enfin, dans mon GtkTreeView je n'ajoute volontairement pas la première colonne. C'est une colonne qui servirait à recueillir des informations mais que j'aimerais ne pas afficher. Le résultat est bien celui escompté mais Valgrind renvoie :

==2135== 376 (124 direct, 252 indirect) bytes in 1 blocks are definitely lost in loss record 3,992 of 4,171
==2135== at 0x4023F50: malloc (vg_replace_malloc.c:236)
==2135== by 0x484CED3: g_malloc (in /lib/libglib-2.0.so.0.2400.1)
==2135== by 0x4862AB8: g_slice_alloc (in /lib/libglib-2.0.so.0.2400.1)
==2135== by 0x4862DB4: g_slice_alloc0 (in /lib/libglib-2.0.so.0.2400.1)
==2135== by 0x47E45C6: g_type_create_instance (in /usr/lib/libgobject-2.0.so.0.2400.1)
==2135== by 0x47C8907: ??? (in /usr/lib/libgobject-2.0.so.0.2400.1)
==2135== by 0x47CA079: g_object_newv (in /usr/lib/libgobject-2.0.so.0.2400.1)
==2135== by 0x47CA937: g_object_new (in /usr/lib/libgobject-2.0.so.0.2400.1)
==2135== by 0x431CB06: gtk_tree_view_column_new (in /usr/lib/libgtk-x11-2.0.so.0.2000.1)
==2135== by 0x431CB23: gtk_tree_view_column_new_with_attributes (in /usr/lib/libgtk-x11-2.0.so.0.2000.1)
==2135== by 0x8048D43: create_treeview (main.c:27)
==2135== by 0x8048F72: create_window (main.c:75)
==2135== by 0x8048F9C: main (main.c:87)

Quelle est mon erreur ?

En résumé, quelles sont les choses mal écrites dans le code, est-ce que mon utilisation de Valgrind est bonne, comment éviter tous ces "faux positifs" ? J'ajoute que j'utilise la version 2.20 de Gtk sur Debian si jamais ça avait une quelconque importance.

Merci beaucoup pour votre aide et les connaissances que vous partagez.