[pango/threadsafe-failed-attempt: 5/11] Make PangoFcFontSet threadsafe

[Behdad Esfahbod <behdad src gnome org>]

commit 0336db39ebbd94a2ba53370e188b40dcab6b9a32
Author: Behdad Esfahbod <behdad behdad org>
Date:   Mon Oct 15 19:56:42 2012 -0500

    Make PangoFcFontSet threadsafe

 pango/pangofc-fontmap.c |   26 ++++++++++++++++++++------
 1 files changed, 20 insertions(+), 6 deletions(-)
---
diff --git a/pango/pangofc-fontmap.c b/pango/pangofc-fontmap.c
index 5be2b81..6e47d08 100644
--- a/pango/pangofc-fontmap.c
+++ b/pango/pangofc-fontmap.c
@@ -811,6 +811,8 @@ struct _PangoFcFontset
   GPtrArray *coverages;
 
   GList *cache_link;
+
+  GMutex lock;
 };
 
 typedef PangoFontsetClass PangoFcFontsetClass;
@@ -873,13 +875,21 @@ static PangoFont *
 pango_fc_fontset_get_font_at (PangoFcFontset *fontset,
 			      unsigned int i)
 {
-  while (i >= fontset->fonts->len)
+  /* Meh, mixing atomic and mutexes in a haphazard way... */
+  int len = g_atomic_int_get (&fontset->fonts->len);
+
+  if (i >= len)
     {
-      PangoFont *font = pango_fc_fontset_load_next_font (fontset);
-      g_ptr_array_add (fontset->fonts, font);
-      g_ptr_array_add (fontset->coverages, NULL);
-      if (!font)
-        return NULL;
+      g_mutex_lock (&fontset->lock);
+      while (i >= fontset->fonts->len)
+	{
+	  PangoFont *font = pango_fc_fontset_load_next_font (fontset);
+	  g_ptr_array_add (fontset->fonts, font);
+	  g_ptr_array_add (fontset->coverages, NULL);
+	  if (!font)
+	    return NULL;
+	}
+      g_mutex_unlock (&fontset->lock);
     }
 
   return g_ptr_array_index (fontset->fonts, i);
@@ -933,6 +943,10 @@ pango_fc_fontset_finalize (GObject *object)
   if (fontset->patterns)
     pango_fc_patterns_unref (fontset->patterns);
 
+  if (fontset->lock.p) /* Work around bug 686192 */
+    g_mutex_clear (&fontset->lock);
+
+
   G_OBJECT_CLASS (pango_fc_fontset_parent_class)->finalize (object);
 }