[evolution-data-server] ESourceRegistry: Use weak references in signal closures.

[Matthew Barnes <mbarnes src gnome org>]

commit 3df3ea89438989a0bca45f4e7e778e6284e18e4b
Author: Matthew Barnes <mbarnes redhat com>
Date:   Fri Mar 8 09:20:23 2013 -0500

    ESourceRegistry: Use weak references in signal closures.
    
    Helps prevent the object from surviving beyond its natural life.

 libedataserver/e-source-registry.c |   89 ++++++++++++++++++++++++------------
 1 files changed, 60 insertions(+), 29 deletions(-)
---
diff --git a/libedataserver/e-source-registry.c b/libedataserver/e-source-registry.c
index fe9504f..3a8d9c3 100644
--- a/libedataserver/e-source-registry.c
+++ b/libedataserver/e-source-registry.c
@@ -138,7 +138,7 @@ struct _CreateContext {
 };
 
 struct _SourceClosure {
-       ESourceRegistry *registry;
+       GWeakRef registry;
        ESource *source;
 };
 
@@ -259,7 +259,7 @@ create_context_free (CreateContext *create_context)
 static void
 source_closure_free (SourceClosure *closure)
 {
-       g_object_unref (closure->registry);
+       g_weak_ref_set (&closure->registry, NULL);
        g_object_unref (closure->source);
 
        g_slice_free (SourceClosure, closure);
@@ -476,11 +476,17 @@ static gboolean
 source_registry_source_changed_idle_cb (gpointer user_data)
 {
        SourceClosure *closure = user_data;
+       ESourceRegistry *registry;
 
-       g_signal_emit (
-               closure->registry,
-               signals[SOURCE_CHANGED], 0,
-               closure->source);
+       registry = g_weak_ref_get (&closure->registry);
+
+       if (registry != NULL) {
+               g_signal_emit (
+                       registry,
+                       signals[SOURCE_CHANGED], 0,
+                       closure->source);
+               g_object_unref (registry);
+       }
 
        return FALSE;
 }
@@ -489,17 +495,24 @@ static gboolean
 source_registry_source_notify_enabled_idle_cb (gpointer user_data)
 {
        SourceClosure *closure = user_data;
+       ESourceRegistry *registry;
 
-       if (e_source_get_enabled (closure->source))
-               g_signal_emit (
-                       closure->registry,
-                       signals[SOURCE_ENABLED], 0,
-                       closure->source);
-       else
-               g_signal_emit (
-                       closure->registry,
-                       signals[SOURCE_DISABLED], 0,
-                       closure->source);
+       registry = g_weak_ref_get (&closure->registry);
+
+       if (registry != NULL) {
+               if (e_source_get_enabled (closure->source)) {
+                       g_signal_emit (
+                               registry,
+                               signals[SOURCE_ENABLED], 0,
+                               closure->source);
+               } else {
+                       g_signal_emit (
+                               registry,
+                               signals[SOURCE_DISABLED], 0,
+                               closure->source);
+               }
+               g_object_unref (registry);
+       }
 
        return FALSE;
 }
@@ -512,7 +525,7 @@ source_registry_source_changed_cb (ESource *source,
        SourceClosure *closure;
 
        closure = g_slice_new0 (SourceClosure);
-       closure->registry = g_object_ref (registry);
+       g_weak_ref_set (&closure->registry, registry);
        closure->source = g_object_ref (source);
 
        idle_source = g_idle_source_new ();
@@ -533,7 +546,7 @@ source_registry_source_notify_enabled_cb (ESource *source,
        SourceClosure *closure;
 
        closure = g_slice_new0 (SourceClosure);
-       closure->registry = g_object_ref (registry);
+       g_weak_ref_set (&closure->registry, registry);
        closure->source = g_object_ref (source);
 
        idle_source = g_idle_source_new ();
@@ -635,10 +648,17 @@ static gboolean
 source_registry_object_added_idle_cb (gpointer user_data)
 {
        SourceClosure *closure = user_data;
-       ESourceRegistry *registry = closure->registry;
-       ESource *source = closure->source;
+       ESourceRegistry *registry;
+
+       registry = g_weak_ref_get (&closure->registry);
 
-       g_signal_emit (registry, signals[SOURCE_ADDED], 0, source);
+       if (registry != NULL) {
+               g_signal_emit (
+                       registry,
+                       signals[SOURCE_ADDED], 0,
+                       closure->source);
+               g_object_unref (registry);
+       }
 
        return FALSE;
 }
@@ -664,7 +684,7 @@ source_registry_object_added_cb (GDBusObjectManager *object_manager,
        /* Schedule a callback on the ESourceRegistry's GMainContext. */
 
        closure = g_slice_new0 (SourceClosure);
-       closure->registry = g_object_ref (registry);
+       g_weak_ref_set (&closure->registry, registry);
        closure->source = g_object_ref (source);
 
        idle_source = g_idle_source_new ();
@@ -682,13 +702,24 @@ static gboolean
 source_registry_object_removed_idle_cb (gpointer user_data)
 {
        SourceClosure *closure = user_data;
-       ESourceRegistry *registry = closure->registry;
-       ESource *source = closure->source;
+       ESourceRegistry *registry;
+
+       registry = g_weak_ref_get (&closure->registry);
+
+       if (registry != NULL) {
+               ESource *source = closure->source;
 
-       /* Removing the ESource won't finalize it because the
-        * SourceClosure itself still holds a reference on it. */
-       if (source_registry_sources_remove (registry, source))
-               g_signal_emit (registry, signals[SOURCE_REMOVED], 0, source);
+               /* Removing the ESource won't finalize it because the
+                * SourceClosure itself still holds a reference on it. */
+               if (source_registry_sources_remove (registry, source)) {
+                       g_signal_emit (
+                               registry,
+                               signals[SOURCE_REMOVED], 0,
+                               source);
+               }
+
+               g_object_unref (registry);
+       }
 
        return FALSE;
 }
@@ -716,7 +747,7 @@ source_registry_object_removed_cb (GDBusObjectManager *manager,
        /* Schedule a callback on the ESourceRegistry's GMainContext. */
 
        closure = g_slice_new0 (SourceClosure);
-       closure->registry = g_object_ref (registry);
+       g_weak_ref_set (&closure->registry, registry);
        closure->source = g_object_ref (source);
 
        idle_source = g_idle_source_new ();