[pango] Port pangofc-font.c to GWeakRef

[Behdad Esfahbod <behdad src gnome org>]

commit aca468cdc2ea66ce6dc8cfc70424a2c5309354fa
Author: Behdad Esfahbod <behdad behdad org>
Date:   Wed Aug 29 09:54:19 2012 -0400

    Port pangofc-font.c to GWeakRef

 configure.in         |    2 +-
 pango/pangofc-font.c |   50 ++++++++++++++++++++++++++------------------------
 2 files changed, 27 insertions(+), 25 deletions(-)
---
diff --git a/configure.in b/configure.in
index a8fb393..28c913d 100644
--- a/configure.in
+++ b/configure.in
@@ -450,7 +450,7 @@ fi
 #
 # Checks for GLib
 #
-GLIB_REQUIRED_VERSION=2.31.0
+GLIB_REQUIRED_VERSION=2.32.0
 GLIB_MODULES="glib-2.0 >= $GLIB_REQUIRED_VERSION gobject-2.0 gmodule-no-export-2.0"
 
 PKG_CHECK_MODULES(GLIB, $GLIB_MODULES, :,
diff --git a/pango/pangofc-font.c b/pango/pangofc-font.c
index f45298a..9e0ea5d 100644
--- a/pango/pangofc-font.c
+++ b/pango/pangofc-font.c
@@ -45,7 +45,6 @@ struct _PangoFcFontPrivate
   PangoFcDecoder *decoder;
   PangoFcFontKey *key;
   PangoFcCmapCache *cmap_cache;
-  gboolean has_weak_pointer; /* have set a weak_pointer from fontmap to us */
 };
 
 static gboolean pango_fc_font_real_has_char  (PangoFcFont *font,
@@ -136,19 +135,17 @@ pango_fc_font_finalize (GObject *object)
 {
   PangoFcFont *fcfont = PANGO_FC_FONT (object);
   PangoFcFontPrivate *priv = fcfont->priv;
+  PangoFcFontMap *fontmap;
 
   g_slist_foreach (fcfont->metrics_by_lang, (GFunc)free_metrics_info, NULL);
   g_slist_free (fcfont->metrics_by_lang);
 
-  if (fcfont->fontmap)
+  fontmap = g_weak_ref_get ((GWeakRef *) &fcfont->fontmap);
+  if (fontmap)
     {
       _pango_fc_font_map_remove (PANGO_FC_FONT_MAP (fcfont->fontmap), fcfont);
-      if (priv->has_weak_pointer)
-        {
-	  priv->has_weak_pointer = FALSE;
-	  g_object_remove_weak_pointer (G_OBJECT (fcfont->fontmap), (gpointer *) (gpointer) &fcfont->fontmap);
-	}
-      fcfont->fontmap = NULL;
+      g_weak_ref_clear ((GWeakRef *) &fcfont->fontmap);
+      g_object_unref (fontmap);
     }
 
   FcPatternDestroy (fcfont->font_pattern);
@@ -227,13 +224,7 @@ pango_fc_font_set_property (GObject       *object,
 	PangoFcFontMap *fcfontmap = PANGO_FC_FONT_MAP (g_value_get_object (value));
 
 	g_return_if_fail (fcfont->fontmap == NULL);
-	fcfont->fontmap = (PangoFontMap *) fcfontmap;
-	if (fcfont->fontmap)
-	  {
-	    PangoFcFontPrivate *priv = fcfont->priv;
-	    priv->has_weak_pointer = TRUE;
-	    g_object_add_weak_pointer (G_OBJECT (fcfont->fontmap), (gpointer *) (gpointer) &fcfont->fontmap);
-	  }
+	g_weak_ref_set ((GWeakRef *) &fcfont->fontmap, fcfontmap);
       }
       goto set_decoder;
 
@@ -267,7 +258,10 @@ pango_fc_font_get_property (GObject       *object,
     case PROP_FONTMAP:
       {
 	PangoFcFont *fcfont = PANGO_FC_FONT (object);
-	g_value_set_object (value, fcfont->fontmap);
+	PangoFontMap *fontmap = g_weak_ref_get ((GWeakRef *) &fcfont->fontmap);
+	g_value_set_object (value, fontmap);
+	if (fontmap)
+	  g_object_unref (fontmap);
       }
       break;
     default:
@@ -331,6 +325,8 @@ pango_fc_font_get_coverage (PangoFont     *font,
   PangoFcFont *fcfont = (PangoFcFont *)font;
   PangoFcFontPrivate *priv = fcfont->priv;
   FcCharSet *charset;
+  PangoFcFontMap *fontmap;
+  PangoCoverage *coverage;
 
   if (priv->decoder)
     {
@@ -338,11 +334,13 @@ pango_fc_font_get_coverage (PangoFont     *font,
       return _pango_fc_font_map_fc_to_coverage (charset);
     }
 
-  if (!fcfont->fontmap)
+  fontmap = g_weak_ref_get ((GWeakRef *) &fcfont->fontmap);
+  if (!fontmap)
     return pango_coverage_new ();
 
-  return _pango_fc_font_map_get_coverage (PANGO_FC_FONT_MAP (fcfont->fontmap),
-					  fcfont);
+  coverage = _pango_fc_font_map_get_coverage (fontmap, fcfont);
+  g_object_unref (fontmap);
+  return coverage;
 }
 
 /* For Xft, it would be slightly more efficient to simply to
@@ -540,11 +538,9 @@ pango_fc_font_get_metrics (PangoFont     *font,
       PangoFontMap *fontmap;
       PangoContext *context;
 
-      /* XXX this is racy.  because weakref's are racy... */
-      fontmap = fcfont->fontmap;
+      fontmap = g_weak_ref_get ((GWeakRef *) &fcfont->fontmap);
       if (!fontmap)
 	return pango_font_metrics_new ();
-      fontmap = g_object_ref (fontmap);
 
       info = g_slice_new0 (PangoFcMetricsInfo);
 
@@ -591,6 +587,7 @@ pango_fc_font_get_font_map (PangoFont *font)
 {
   PangoFcFont *fcfont = PANGO_FC_FONT (font);
 
+  /* MT-unsafe.  Oh well...  The API is unsafe. */
   return fcfont->fontmap;
 }
 
@@ -621,8 +618,13 @@ pango_fc_font_real_get_glyph (PangoFcFont *font,
 
   if (G_UNLIKELY (priv->cmap_cache == NULL))
     {
-      priv->cmap_cache = _pango_fc_font_map_get_cmap_cache ((PangoFcFontMap *) font->fontmap,
-							    font);
+      PangoFcFontMap *fontmap = g_weak_ref_get ((GWeakRef *) &font->fontmap);
+      if (G_UNLIKELY (!fontmap))
+        return 0;
+
+      priv->cmap_cache = _pango_fc_font_map_get_cmap_cache (fontmap, font);
+
+      g_object_unref (fontmap);
 
       if (G_UNLIKELY (!priv->cmap_cache))
 	return 0;