[gtksourceview] Use a DSO destructor

[Sébastien Wilmet <swilmet src gnome org>]

commit e761de9c2bee90c232875bbc41e6e73e1f63e145
Author: Sébastien Wilmet <swilmet gnome org>
Date:   Tue Aug 2 07:54:59 2016 +0200

    Use a DSO destructor
    
    For the unit tests in testsuite/, the destructor is not called because
    libgtksourceview-core.la is statically linked to the unit test programs.
    A solution would be to have the private function
    _gtksourceview_shutdown() that can be called in unit tests.
    
    But the destructor is correctly called in e.g. tests/test-widget or
    gedit, so it is already useful.
    
    At least with gobject-list
    https://blogs.gnome.org/danni/2011/02/17/ld_preload-gobject-lifetime-debugging-tool/
    we can verify that all GtkSource GObjects are finalized. Unfortunately
    the GtkSourceView destructor runs *after* the "Still Alive:" list that
    gobject-list prints. But by counting the number of "Finalized object"
    lines that follow, we can verify that all GObject are finalized.

 gtksourceview/gtksourcelanguagemanager.c    |   20 ++++++++++-----
 gtksourceview/gtksourcelanguagemanager.h    |    3 ++
 gtksourceview/gtksourcestyleschememanager.c |   20 ++++++++++-----
 gtksourceview/gtksourcestyleschememanager.h |    4 +++
 gtksourceview/gtksourceview-init.c          |   34 ++++++++++++++++++++++++++-
 5 files changed, 66 insertions(+), 15 deletions(-)
---
diff --git a/gtksourceview/gtksourcelanguagemanager.c b/gtksourceview/gtksourcelanguagemanager.c
index ff3850d..3f56a35 100644
--- a/gtksourceview/gtksourcelanguagemanager.c
+++ b/gtksourceview/gtksourcelanguagemanager.c
@@ -68,6 +68,8 @@ struct _GtkSourceLanguageManagerPrivate
        gchar          **ids; /* Cache the IDs of the available languages */
 };
 
+static GtkSourceLanguageManager *default_instance;
+
 G_DEFINE_TYPE_WITH_PRIVATE (GtkSourceLanguageManager, gtk_source_language_manager, G_TYPE_OBJECT)
 
 static void
@@ -203,16 +205,20 @@ gtk_source_language_manager_new (void)
 GtkSourceLanguageManager *
 gtk_source_language_manager_get_default (void)
 {
-       static GtkSourceLanguageManager *instance;
-
-       if (instance == NULL)
+       if (default_instance == NULL)
        {
-               instance = gtk_source_language_manager_new ();
-               g_object_add_weak_pointer (G_OBJECT (instance),
-                                          (gpointer) &instance);
+               default_instance = gtk_source_language_manager_new ();
+               g_object_add_weak_pointer (G_OBJECT (default_instance),
+                                          (gpointer) &default_instance);
        }
 
-       return instance;
+       return default_instance;
+}
+
+GtkSourceLanguageManager *
+_gtk_source_language_manager_peek_default (void)
+{
+       return default_instance;
 }
 
 static void
diff --git a/gtksourceview/gtksourcelanguagemanager.h b/gtksourceview/gtksourcelanguagemanager.h
index d3d7657..71ce257 100644
--- a/gtksourceview/gtksourcelanguagemanager.h
+++ b/gtksourceview/gtksourcelanguagemanager.h
@@ -92,6 +92,9 @@ GtkSourceLanguage      *gtk_source_language_manager_guess_language            
(GtkSourceLangua
                                                                                 const gchar              
*filename,
                                                                                 const gchar              
*content_type);
 
+G_GNUC_INTERNAL
+GtkSourceLanguageManager *_gtk_source_language_manager_peek_default            (void);
+
 G_END_DECLS
 
 #endif /* GTK_SOURCE_LANGUAGE_MANAGER_H */
diff --git a/gtksourceview/gtksourcestyleschememanager.c b/gtksourceview/gtksourcestyleschememanager.c
index 161536e..eeae1fd 100644
--- a/gtksourceview/gtksourcestyleschememanager.c
+++ b/gtksourceview/gtksourcestyleschememanager.c
@@ -57,6 +57,8 @@ enum {
        PROP_SCHEME_IDS
 };
 
+static GtkSourceStyleSchemeManager *default_instance;
+
 G_DEFINE_TYPE_WITH_PRIVATE (GtkSourceStyleSchemeManager, gtk_source_style_scheme_manager, G_TYPE_OBJECT)
 
 static void
@@ -202,16 +204,20 @@ gtk_source_style_scheme_manager_new (void)
 GtkSourceStyleSchemeManager *
 gtk_source_style_scheme_manager_get_default (void)
 {
-       static GtkSourceStyleSchemeManager *instance;
-
-       if (instance == NULL)
+       if (default_instance == NULL)
        {
-               instance = gtk_source_style_scheme_manager_new ();
-               g_object_add_weak_pointer (G_OBJECT (instance),
-                                          (gpointer) &instance);
+               default_instance = gtk_source_style_scheme_manager_new ();
+               g_object_add_weak_pointer (G_OBJECT (default_instance),
+                                          (gpointer) &default_instance);
        }
 
-       return instance;
+       return default_instance;
+}
+
+GtkSourceStyleSchemeManager *
+_gtk_source_style_scheme_manager_peek_default (void)
+{
+       return default_instance;
 }
 
 static gboolean
diff --git a/gtksourceview/gtksourcestyleschememanager.h b/gtksourceview/gtksourcestyleschememanager.h
index ed35d0a..f0225ea 100644
--- a/gtksourceview/gtksourcestyleschememanager.h
+++ b/gtksourceview/gtksourcestyleschememanager.h
@@ -99,6 +99,10 @@ GTK_SOURCE_AVAILABLE_IN_ALL
 GtkSourceStyleScheme   *gtk_source_style_scheme_manager_get_scheme             (GtkSourceStyleSchemeManager  
  *manager,
                                                                                 const gchar                  
  *scheme_id);
 
+G_GNUC_INTERNAL
+GtkSourceStyleSchemeManager *
+                        _gtk_source_style_scheme_manager_peek_default          (void);
+
 G_END_DECLS
 
 #endif /* GTK_SOURCE_STYLE_SCHEME_MANAGER_H */
diff --git a/gtksourceview/gtksourceview-init.c b/gtksourceview/gtksourceview-init.c
index 03eb647..1403c7e 100644
--- a/gtksourceview/gtksourceview-init.c
+++ b/gtksourceview/gtksourceview-init.c
@@ -19,7 +19,10 @@
  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  */
 
-/* Init i18n */
+/* Constructor to init i18n.
+ * Destructor to release remaining allocated memory (useful when using
+ * memory-debugging tools).
+ */
 
 #ifdef HAVE_CONFIG_H
 #include <config.h>
@@ -30,6 +33,8 @@
 #endif
 
 #include "gconstructor.h"
+#include "gtksourcelanguagemanager.h"
+#include "gtksourcestyleschememanager.h"
 
 #ifdef G_OS_WIN32
 static HMODULE gtksourceview_dll;
@@ -127,6 +132,19 @@ gtksourceview_init (void)
 #endif /* ENABLE_NLS */
 }
 
+static void
+gtksourceview_shutdown (void)
+{
+       GtkSourceLanguageManager *language_manager;
+       GtkSourceStyleSchemeManager *style_scheme_manager;
+
+       language_manager = _gtk_source_language_manager_peek_default ();
+       g_clear_object (&language_manager);
+
+       style_scheme_manager = _gtk_source_style_scheme_manager_peek_default ();
+       g_clear_object (&style_scheme_manager);
+}
+
 #if defined (G_OS_WIN32)
 
 BOOL WINAPI DllMain (HINSTANCE hinstDLL,
@@ -146,6 +164,9 @@ DllMain (HINSTANCE hinstDLL,
                        break;
 
                case DLL_THREAD_DETACH:
+                       gtksourceview_shutdown ();
+                       break;
+
                default:
                        /* do nothing */
                        break;
@@ -167,6 +188,17 @@ gtksourceview_constructor (void)
        gtksourceview_init ();
 }
 
+#  ifdef G_DEFINE_DESTRUCTOR_NEEDS_PRAGMA
+#    pragma G_DEFINE_DESTRUCTOR_PRAGMA_ARGS(gtksourceview_destructor)
+#  endif
+G_DEFINE_DESTRUCTOR (gtksourceview_destructor)
+
+static void
+gtksourceview_destructor (void)
+{
+       gtksourceview_shutdown ();
+}
+
 #else
 #  error Your platform/compiler is missing constructor support
 #endif