[evolution-data-server] Make e_dbus_server_load_modules() idempotent.

[Matthew Barnes <mbarnes src gnome org>]

commit ed1963ee49973de94a189fa30974d5666fec8d0a
Author: Matthew Barnes <mbarnes redhat com>
Date:   Tue Apr 10 18:44:39 2012 -0400

    Make e_dbus_server_load_modules() idempotent.
    
    The function now keeps a static hash table of module directories it has
    loaded, and simply returns if it detects a previously loaded directory.

 libebackend/e-dbus-server.c |   18 ++++++++++++++++++
 1 files changed, 18 insertions(+), 0 deletions(-)
---
diff --git a/libebackend/e-dbus-server.c b/libebackend/e-dbus-server.c
index 52defc2..306b85a 100644
--- a/libebackend/e-dbus-server.c
+++ b/libebackend/e-dbus-server.c
@@ -60,6 +60,10 @@ enum {
 
 static guint signals[LAST_SIGNAL];
 
+static GHashTable *directories_loaded;
+G_LOCK_DEFINE_STATIC (directories_loaded);
+
+
 G_DEFINE_ABSTRACT_TYPE_WITH_CODE (
 	EDBusServer, e_dbus_server, G_TYPE_OBJECT,
 	G_IMPLEMENT_INTERFACE (E_TYPE_EXTENSIBLE, NULL))
@@ -424,6 +428,8 @@ void
 e_dbus_server_load_modules (EDBusServer *server)
 {
 	EDBusServerClass *class;
+	gboolean already_loaded;
+	const gchar *directory;
 	GList *list;
 
 	g_return_if_fail (E_IS_DBUS_SERVER (server));
@@ -431,6 +437,18 @@ e_dbus_server_load_modules (EDBusServer *server)
 	class = E_DBUS_SERVER_GET_CLASS (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);
+
+	if (already_loaded)
+		return;
+
 	list = e_module_load_all_in_directory (class->module_directory);
 	g_list_free_full (list, (GDestroyNotify) g_type_module_unuse);
 }