[evolution-data-server] Make sure EDBusServer modules are loaded only once

[Milan Crha <mcrha src gnome org>]

commit 9191fbe83497c25962f26f14bd93866ad8f7be6e
Author: Milan Crha <mcrha redhat com>
Date:   Tue Nov 24 11:46:18 2015 +0100

    Make sure EDBusServer modules are loaded only once
    
    After recent commit which checks for modules directory changes
    the changed modules could be loaded multiple times, which results
    in a GType runtime warnings and eventually a crash. This commit
    ensures that each module is loaded only once, for a price of not
    have loaded the most recent version of the module, which is not
    a problem, because it's not the aim of the modules directory
    change watcher.

 libebackend/e-data-factory.c |    3 +-
 libebackend/e-dbus-server.c  |   56 +++++++++++++++++++++++++++++------------
 2 files changed, 41 insertions(+), 18 deletions(-)
---
diff --git a/libebackend/e-data-factory.c b/libebackend/e-data-factory.c
index 80ecd9d..85a2bd4 100644
--- a/libebackend/e-data-factory.c
+++ b/libebackend/e-data-factory.c
@@ -812,7 +812,8 @@ data_factory_quit_server (EDBusServer *server,
        class = E_DATA_FACTORY_GET_CLASS (E_DATA_FACTORY (server));
 
        skeleton_interface = class->get_dbus_interface_skeleton (server);
-       g_dbus_interface_skeleton_unexport (skeleton_interface);
+       if (skeleton_interface && g_dbus_interface_skeleton_get_connection (skeleton_interface))
+               g_dbus_interface_skeleton_unexport (skeleton_interface);
 
        /* Chain up to parent's quit_server() method. */
        E_DBUS_SERVER_CLASS (e_data_factory_parent_class)->
diff --git a/libebackend/e-dbus-server.c b/libebackend/e-dbus-server.c
index a801760..9e86e25 100644
--- a/libebackend/e-dbus-server.c
+++ b/libebackend/e-dbus-server.c
@@ -66,8 +66,8 @@ enum {
 
 static guint signals[LAST_SIGNAL];
 
-static GHashTable *directories_loaded;
-G_LOCK_DEFINE_STATIC (directories_loaded);
+static GHashTable *loaded_modules;
+G_LOCK_DEFINE_STATIC (loaded_modules);
 
 G_DEFINE_ABSTRACT_TYPE_WITH_CODE (
        EDBusServer, e_dbus_server, G_TYPE_OBJECT,
@@ -254,8 +254,10 @@ dbus_server_quit_server (EDBusServer *server,
        /* If we're reloading, voluntarily relinquish our bus
         * name to avoid triggering a "bus-name-lost" signal. */
        if (code == E_DBUS_SERVER_EXIT_RELOAD) {
-               g_bus_unown_name (server->priv->bus_owner_id);
-               server->priv->bus_owner_id = 0;
+               if (server->priv->bus_owner_id) {
+                       g_bus_unown_name (server->priv->bus_owner_id);
+                       server->priv->bus_owner_id = 0;
+               }
        }
 
        server->priv->exit_code = code;
@@ -546,11 +548,19 @@ dbus_server_module_directory_changed_cb (GFileMonitor *monitor,
                if (filename && g_str_has_suffix (filename, "." G_MODULE_SUFFIX)) {
                        if (event_type == G_FILE_MONITOR_EVENT_CREATED ||
                            event_type == G_FILE_MONITOR_EVENT_MOVED_IN) {
-                               EModule *module;
+                               G_LOCK (loaded_modules);
+
+                               if (!g_hash_table_contains (loaded_modules, filename)) {
+                                       EModule *module;
+
+                                       g_hash_table_add (loaded_modules, g_strdup (filename));
 
-                               module = e_module_load_file (filename);
-                               if (module)
-                                       g_type_module_unuse ((GTypeModule *) module);
+                                       module = e_module_load_file (filename);
+                                       if (module)
+                                               g_type_module_unuse ((GTypeModule *) module);
+                               }
+
+                               G_UNLOCK (loaded_modules);
                        }
 
                        e_dbus_server_quit (server, E_DBUS_SERVER_EXIT_RELOAD);
@@ -574,8 +584,7 @@ e_dbus_server_load_modules (EDBusServer *server)
 {
        EDBusServerClass *class;
        gboolean already_loaded;
-       const gchar *directory;
-       GList *list;
+       GList *list, *link;
 
        g_return_if_fail (E_IS_DBUS_SERVER (server));
 
@@ -583,13 +592,13 @@ e_dbus_server_load_modules (EDBusServer *server)
        g_return_if_fail (class->module_directory != NULL);
 
        /* This ensures a module directory is only loaded once. */
-       G_LOCK (directories_loaded);
-       if (directories_loaded == NULL)
-               directories_loaded = g_hash_table_new (NULL, NULL);
-       directory = g_intern_string (class->module_directory);
-       already_loaded = g_hash_table_contains (directories_loaded, directory);
-       g_hash_table_add (directories_loaded, (gpointer) directory);
-       G_UNLOCK (directories_loaded);
+       G_LOCK (loaded_modules);
+       if (loaded_modules == NULL)
+               loaded_modules = g_hash_table_new_full (g_str_hash, g_str_equal, g_free, NULL);
+       already_loaded = g_hash_table_contains (loaded_modules, class->module_directory);
+       if (!already_loaded)
+               g_hash_table_add (loaded_modules, g_strdup (class->module_directory));
+       G_UNLOCK (loaded_modules);
 
        if (!server->priv->directory_monitor) {
                GFile *dir_file;
@@ -607,6 +616,19 @@ e_dbus_server_load_modules (EDBusServer *server)
        if (already_loaded)
                return;
 
+       G_LOCK (loaded_modules);
+
        list = e_module_load_all_in_directory (class->module_directory);
+       for (link = list; link; link = g_list_next (link)) {
+               EModule *module = link->data;
+
+               if (!module || !e_module_get_filename (module))
+                       continue;
+
+               g_hash_table_add (loaded_modules, g_strdup (e_module_get_filename (module)));
+       }
+
+       G_UNLOCK (loaded_modules);
+
        g_list_free_full (list, (GDestroyNotify) g_type_module_unuse);
 }