Merge branch 'fc-fontmap-crash' into 'master'

Use atomic reference counting for PangoFcPatterns

Closes #571

See merge request GNOME/pango!354

1 files changed, 25 insertions, 22 deletions

diff --git a/pango/pangofc-fontmap.c b/pango/pangofc-fontmap.c
index 0df9de9f..7ea5dc52 100644
--- a/pango/pangofc-fontmap.c
+++ b/pango/pangofc-fontmap.c
@@ -100,13 +100,24 @@
  *   FcCharSetMerge().
  */
 
+typedef enum {
+  /* Initial state; Fontconfig is not initialized yet */
+  DEFAULT_CONFIG_NOT_INITIALIZED,
+
+  /* We have a thread doing Fontconfig initialization in the background */
+  DEFAULT_CONFIG_INITIALIZING,
+
+  /* FcInit() finished and its default configuration is loaded */
+  DEFAULT_CONFIG_INITIALIZED
+} DefaultConfig;
+
 /* We call FcInit in a thread and set fc_initialized
  * when done, and are protected by a mutex. The thread
  * signals the cond when FcInit is done.
  */
 static GMutex fc_init_mutex;
 static GCond fc_init_cond;
-static int fc_initialized = 0;
+static DefaultConfig fc_initialized = DEFAULT_CONFIG_NOT_INITIALIZED;
 
 
 typedef struct _PangoFcFontFaceData PangoFcFontFaceData;
@@ -743,8 +754,6 @@ pango_fc_font_key_get_variations (const PangoFcFontKey *key)
  */
 
 struct _PangoFcPatterns {
-  guint ref_count;
-
   PangoFcFontMap *fontmap;
 
   /* match and fontset are initialized in a thread,
@@ -883,11 +892,10 @@ pango_fc_patterns_new (FcPattern *pat, PangoFcFontMap *fontmap)
   if (pats)
     return pango_fc_patterns_ref (pats);
 
-  pats = g_slice_new0 (PangoFcPatterns);
+  pats = g_atomic_rc_box_new0 (PangoFcPatterns);
 
   pats->fontmap = fontmap;
 
-  pats->ref_count = 1;
   FcPatternReference (pat);
   pats->pattern = pat;
 
@@ -909,22 +917,13 @@ pango_fc_patterns_new (FcPattern *pat, PangoFcFontMap *fontmap)
 static PangoFcPatterns *
 pango_fc_patterns_ref (PangoFcPatterns *pats)
 {
-  g_return_val_if_fail (pats->ref_count > 0, NULL);
-
-  pats->ref_count++;
-
-  return pats;
+  return g_atomic_rc_box_acquire (pats);
 }
 
 static void
-pango_fc_patterns_unref (PangoFcPatterns *pats)
+free_patterns (gpointer data)
 {
-  g_return_if_fail (pats->ref_count > 0);
-
-  pats->ref_count--;
-
-  if (pats->ref_count)
-    return;
+  PangoFcPatterns *pats = data;
 
   /* Only remove from fontmap hash if we are in it.  This is not necessarily
    * the case after a cache_clear() call. */
@@ -944,8 +943,12 @@ pango_fc_patterns_unref (PangoFcPatterns *pats)
 
   g_cond_clear (&pats->cond);
   g_mutex_clear (&pats->mutex);
+}
 
-  g_slice_free (PangoFcPatterns, pats);
+static void
+pango_fc_patterns_unref (PangoFcPatterns *pats)
+{
+  g_atomic_rc_box_release_full (pats, free_patterns);
 }
 
 static FcPattern *
@@ -1350,7 +1353,7 @@ init_in_thread (gpointer task_data)
   pango_trace_mark (before, "FcInit", NULL);
 
   g_mutex_lock (&fc_init_mutex);
-  fc_initialized = 2;
+  fc_initialized = DEFAULT_CONFIG_INITIALIZED;
   g_cond_broadcast (&fc_init_cond);
   g_mutex_unlock (&fc_init_mutex);
 
@@ -1362,11 +1365,11 @@ start_init_in_thread (PangoFcFontMap *fcfontmap)
 {
   g_mutex_lock (&fc_init_mutex);
 
-  if (fc_initialized == 0)
+  if (fc_initialized == DEFAULT_CONFIG_NOT_INITIALIZED)
     {
       GThread *thread;
 
-      fc_initialized = 1;
+      fc_initialized = DEFAULT_CONFIG_INITIALIZING;
       thread = g_thread_new ("[pango] FcInit", init_in_thread, NULL);
       g_thread_unref (thread);
     }
@@ -1381,7 +1384,7 @@ wait_for_fc_init (void)
   gboolean waited = FALSE;
 
   g_mutex_lock (&fc_init_mutex);
-  while (fc_initialized < 2)
+  while (fc_initialized < DEFAULT_CONFIG_INITIALIZED)
     {
       waited = TRUE;
       g_cond_wait (&fc_init_cond, &fc_init_mutex);