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

[Matthew Barnes <mbarnes src gnome org>]

commit 07330938807945d000ada86be0af7c01cc72be72
Author: Matthew Barnes <mbarnes redhat com>
Date:   Fri Mar 8 09:38:27 2013 -0500

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

 calendar/libecal/e-cal-client.c |  144 +++++++++++++++++++++++----------------
 1 files changed, 86 insertions(+), 58 deletions(-)
---
diff --git a/calendar/libecal/e-cal-client.c b/calendar/libecal/e-cal-client.c
index f0d0ae7..6bc36b9 100644
--- a/calendar/libecal/e-cal-client.c
+++ b/calendar/libecal/e-cal-client.c
@@ -87,7 +87,7 @@ struct _AsyncContext {
 };
 
 struct _SignalClosure {
-       EClient *client;
+       GWeakRef client;
        gchar *property_name;
        gchar *error_message;
        gchar **free_busy_data;
@@ -179,7 +179,7 @@ async_context_free (AsyncContext *async_context)
 static void
 signal_closure_free (SignalClosure *signal_closure)
 {
-       g_object_unref (signal_closure->client);
+       g_weak_ref_set (&signal_closure->client, NULL);
 
        g_free (signal_closure->property_name);
        g_free (signal_closure->error_message);
@@ -399,10 +399,14 @@ static gboolean
 cal_client_emit_backend_died_idle_cb (gpointer user_data)
 {
        SignalClosure *signal_closure = user_data;
+       EClient *client;
 
-       g_signal_emit_by_name (
-               signal_closure->client,
-               "backend-died");
+       client = g_weak_ref_get (&signal_closure->client);
+
+       if (client != NULL) {
+               g_signal_emit_by_name (client, "backend-died");
+               g_object_unref (client);
+       }
 
        return FALSE;
 }
@@ -411,11 +415,16 @@ static gboolean
 cal_client_emit_backend_error_idle_cb (gpointer user_data)
 {
        SignalClosure *signal_closure = user_data;
+       EClient *client;
 
-       g_signal_emit_by_name (
-               signal_closure->client,
-               "backend-error",
-               signal_closure->error_message);
+       client = g_weak_ref_get (&signal_closure->client);
+
+       if (client != NULL) {
+               g_signal_emit_by_name (
+                       client, "backend-error",
+                       signal_closure->error_message);
+               g_object_unref (client);
+       }
 
        return FALSE;
 }
@@ -424,21 +433,29 @@ static gboolean
 cal_client_emit_backend_property_changed_idle_cb (gpointer user_data)
 {
        SignalClosure *signal_closure = user_data;
-       gchar *prop_value = NULL;
+       EClient *client;
 
-       /* XXX Despite appearances, this function does not block. */
-       e_client_get_backend_property_sync (
-               signal_closure->client,
-               signal_closure->property_name,
-               &prop_value, NULL, NULL);
+       client = g_weak_ref_get (&signal_closure->client);
 
-       if (prop_value != NULL) {
-               g_signal_emit_by_name (
-                       signal_closure->client,
-                       "backend-property-changed",
+       if (client != NULL) {
+               gchar *prop_value = NULL;
+
+               /* XXX Despite appearances, this function does not block. */
+               e_client_get_backend_property_sync (
+                       client,
                        signal_closure->property_name,
-                       prop_value);
-               g_free (prop_value);
+                       &prop_value, NULL, NULL);
+
+               if (prop_value != NULL) {
+                       g_signal_emit_by_name (
+                               client,
+                               "backend-property-changed",
+                               signal_closure->property_name,
+                               prop_value);
+                       g_free (prop_value);
+               }
+
+               g_object_unref (client);
        }
 
        return FALSE;
@@ -448,44 +465,50 @@ static gboolean
 cal_client_emit_free_busy_data_idle_cb (gpointer user_data)
 {
        SignalClosure *signal_closure = user_data;
-       GSList *list = NULL;
-       gchar **strv;
-       gint ii;
+       EClient *client;
 
-       strv = signal_closure->free_busy_data;
+       client = g_weak_ref_get (&signal_closure->client);
 
-       for (ii = 0; strv[ii] != NULL; ii++) {
-               ECalComponent *comp;
-               icalcomponent *icalcomp;
-               icalcomponent_kind kind;
+       if (client != NULL) {
+               GSList *list = NULL;
+               gchar **strv;
+               gint ii;
 
-               icalcomp = icalcomponent_new_from_string (strv[ii]);
-               if (icalcomp == NULL)
-                       continue;
+               strv = signal_closure->free_busy_data;
 
-               kind = icalcomponent_isa (icalcomp);
-               if (kind != ICAL_VFREEBUSY_COMPONENT) {
-                       icalcomponent_free (icalcomp);
-                       continue;
-               }
+               for (ii = 0; strv[ii] != NULL; ii++) {
+                       ECalComponent *comp;
+                       icalcomponent *icalcomp;
+                       icalcomponent_kind kind;
 
-               comp = e_cal_component_new ();
-               if (!e_cal_component_set_icalcomponent (comp, icalcomp)) {
-                       icalcomponent_free (icalcomp);
-                       g_object_unref (comp);
-                       continue;
+                       icalcomp = icalcomponent_new_from_string (strv[ii]);
+                       if (icalcomp == NULL)
+                               continue;
+
+                       kind = icalcomponent_isa (icalcomp);
+                       if (kind != ICAL_VFREEBUSY_COMPONENT) {
+                               icalcomponent_free (icalcomp);
+                               continue;
+                       }
+
+                       comp = e_cal_component_new ();
+                       if (!e_cal_component_set_icalcomponent (comp, icalcomp)) {
+                               icalcomponent_free (icalcomp);
+                               g_object_unref (comp);
+                               continue;
+                       }
+
+                       list = g_slist_prepend (list, comp);
                }
 
-               list = g_slist_prepend (list, comp);
-       }
+               list = g_slist_reverse (list);
 
-       list = g_slist_reverse (list);
+               g_signal_emit (client, signals[FREE_BUSY_DATA], 0, list);
 
-       g_signal_emit (
-               signal_closure->client,
-               signals[FREE_BUSY_DATA], 0, list);
+               g_slist_free_full (list, (GDestroyNotify) g_object_unref);
 
-       g_slist_free_full (list, (GDestroyNotify) g_object_unref);
+               g_object_unref (client);
+       }
 
        return FALSE;
 }
@@ -494,11 +517,16 @@ static gboolean
 cal_client_emit_timezone_added_idle_cb (gpointer user_data)
 {
        SignalClosure *signal_closure = user_data;
+       EClient *client;
+
+       client = g_weak_ref_get (&signal_closure->client);
 
-       g_signal_emit_by_name (
-               signal_closure->client,
-               "timezone-added",
-               signal_closure->cached_zone);
+       if (client != NULL) {
+               g_signal_emit_by_name (
+                       client, "timezone-added",
+                       signal_closure->cached_zone);
+               g_object_unref (client);
+       }
 
        return FALSE;
 }
@@ -513,7 +541,7 @@ cal_client_dbus_proxy_error_cb (EDBusCalendar *dbus_proxy,
        SignalClosure *signal_closure;
 
        signal_closure = g_slice_new0 (SignalClosure);
-       signal_closure->client = g_object_ref (client);
+       g_weak_ref_set (&signal_closure->client, client);
        signal_closure->error_message = g_strdup (error_message);
 
        main_context = e_client_ref_main_context (client);
@@ -596,7 +624,7 @@ cal_client_dbus_proxy_notify_cb (EDBusCalendar *dbus_proxy,
                SignalClosure *signal_closure;
 
                signal_closure = g_slice_new0 (SignalClosure);
-               signal_closure->client = g_object_ref (client);
+               g_weak_ref_set (&signal_closure->client, client);
                signal_closure->property_name = g_strdup (backend_prop_name);
 
                main_context = e_client_ref_main_context (client);
@@ -624,7 +652,7 @@ cal_client_dbus_proxy_free_busy_data_cb (EDBusCalendar *dbus_proxy,
        SignalClosure *signal_closure;
 
        signal_closure = g_slice_new0 (SignalClosure);
-       signal_closure->client = g_object_ref (client);
+       g_weak_ref_set (&signal_closure->client, client);
        signal_closure->free_busy_data = g_strdupv (free_busy_data);
 
        main_context = e_client_ref_main_context (client);
@@ -651,7 +679,7 @@ cal_client_name_vanished_cb (GDBusConnection *connection,
        SignalClosure *signal_closure;
 
        signal_closure = g_slice_new0 (SignalClosure);
-       signal_closure->client = g_object_ref (client);
+       g_weak_ref_set (&signal_closure->client, client);
 
        main_context = e_client_ref_main_context (client);
 
@@ -1186,7 +1214,7 @@ cal_client_add_cached_timezone (ETimezoneCache *cache,
                 * internally cached icaltimezone alive for the
                 * duration of the idle callback. */
                signal_closure = g_slice_new0 (SignalClosure);
-               signal_closure->client = g_object_ref (cache);
+               g_weak_ref_set (&signal_closure->client, cache);
                signal_closure->cached_zone = cached_zone;
 
                main_context = e_client_ref_main_context (E_CLIENT (cache));