Remove some unused plugin functionality

Revert the early_initialize changes (which get in the way in the
"libmutter-wm" paradigm), remove the GConf key for setting plugins,
and remove plugin "params", which weren't being used. Also remove all
the logic for unloading and reloading plugins, since the list never
changes after startup now.

https://bugzilla.gnome.org/show_bug.cgi?id=643959

1 files changed, 50 insertions, 312 deletions

diff --git a/src/compositor/meta-plugin-manager.c b/src/compositor/meta-plugin-manager.c
index eee5ffad2..13171ffaf 100644
--- a/src/compositor/meta-plugin-manager.c
+++ b/src/compositor/meta-plugin-manager.c
@@ -35,10 +35,7 @@
 
 #include <clutter/x11/clutter-x11.h>
 
-/*
- * There is only one instace of each module per the process.
- */
-static GHashTable *plugin_modules = NULL;
+static GSList *plugin_types;
 
 /*
  * We have one "default plugin manager" that acts for the first screen,
@@ -46,313 +43,68 @@ static GHashTable *plugin_modules = NULL;
  * plugin managers for each screen. (This is ugly. Probably we should
  * have one plugin manager and only make the plugins per-screen.)
  */
-
 static MetaPluginManager *default_plugin_manager;
 
-static gboolean meta_plugin_manager_reload (MetaPluginManager *plugin_mgr);
-
 struct MetaPluginManager
 {
   MetaScreen   *screen;
 
-  gboolean plugin_load_attempted;
-
-  GList /* MetaPlugin */       *plugins;  /* TODO -- maybe use hash table */
-  GList                        *unload;  /* Plugins that are disabled and pending unload */
-
-  guint         idle_unload_id;
+  GList /* MetaPlugin */ *plugins;  /* TODO -- maybe use hash table */
 };
 
 /*
- * Checks that the plugin is compatible with the WM and sets up the plugin
- * struct.
+ * Loads the given plugin.
  */
-static MetaPlugin *
-meta_plugin_load (MetaPluginManager *mgr,
-                  MetaModule        *module,
-                  const gchar       *params)
-{
-  MetaPlugin *plugin = NULL;
-  GType         plugin_type = meta_module_get_plugin_type (module);
-
-  if (!plugin_type)
-    {
-      g_warning ("Plugin type not registered !!!");
-      return NULL;
-    }
-
-  plugin = g_object_new (plugin_type,
-                         "params", params,
-                         NULL);
-
-  return plugin;
-}
-
-/*
- * Attempst to unload a plugin; returns FALSE if plugin cannot be unloaded at
- * present (e.g., and effect is in progress) and should be scheduled for
- * removal later.
- */
-static gboolean
-meta_plugin_unload (MetaPlugin *plugin)
-{
-  if (meta_plugin_running (plugin))
-    {
-      g_object_set (plugin, "disabled", TRUE, NULL);
-      return FALSE;
-    }
-
-  g_object_unref (plugin);
-
-  return TRUE;
-}
-
-/*
- * Iddle callback to remove plugins that could not be removed directly and are
- * pending for removal.
- */
-static gboolean
-meta_plugin_manager_idle_unload (MetaPluginManager *plugin_mgr)
-{
-  GList *l = plugin_mgr->unload;
-  gboolean dont_remove = TRUE;
-
-  while (l)
-    {
-      MetaPlugin *plugin = l->data;
-
-      if (meta_plugin_unload (plugin))
-        {
-          /* Remove from list */
-          GList *p = l->prev;
-          GList *n = l->next;
-
-          if (!p)
-            plugin_mgr->unload = n;
-          else
-            p->next = n;
-
-          if (n)
-            n->prev = p;
-
-          g_list_free_1 (l);
-
-          l = n;
-        }
-      else
-        l = l->next;
-    }
-
-  if (!plugin_mgr->unload)
-    {
-      /* If no more unloads are pending, remove the handler as well */
-      dont_remove = FALSE;
-      plugin_mgr->idle_unload_id = 0;
-    }
-
-  return dont_remove;
-}
-
-/*
- * Unloads all plugins
- */
-static void
-meta_plugin_manager_unload (MetaPluginManager *plugin_mgr)
-{
-  GList *plugins = plugin_mgr->plugins;
-
-  while (plugins)
-    {
-      MetaPlugin *plugin = plugins->data;
-
-      /* If the plugin could not be removed, move it to the unload list */
-      if (!meta_plugin_unload (plugin))
-        {
-          plugin_mgr->unload = g_list_prepend (plugin_mgr->unload, plugin);
-
-          if (!plugin_mgr->idle_unload_id)
-            {
-              plugin_mgr->idle_unload_id = g_idle_add ((GSourceFunc)
-                            meta_plugin_manager_idle_unload,
-                            plugin_mgr);
-            }
-        }
-
-      plugins = plugins->next;
-    }
-
-  g_list_free (plugin_mgr->plugins);
-  plugin_mgr->plugins = NULL;
-
-  plugin_mgr->plugin_load_attempted = FALSE;
-}
-
-static void
-prefs_changed_callback (MetaPreference pref,
-                        void          *data)
-{
-  MetaPluginManager *plugin_mgr = data;
-
-  if (pref == META_PREF_CLUTTER_PLUGINS)
-    {
-      meta_plugin_manager_reload (plugin_mgr);
-    }
-}
-
-static MetaModule *
-meta_plugin_manager_get_module (const gchar *path)
-{
-  MetaModule *module = g_hash_table_lookup (plugin_modules, path);
-
-  if (!module &&
-      (module = g_object_new (META_TYPE_MODULE, "path", path, NULL)))
-    {
-      g_hash_table_insert (plugin_modules, g_strdup (path), module);
-    }
-
-  return module;
-}
-
-/*
- * Loads all plugins listed in gconf registry.
- */
-gboolean
-meta_plugin_manager_load (MetaPluginManager *plugin_mgr)
+void
+meta_plugin_manager_load (MetaPluginManager *plugin_mgr,
+                          const gchar       *plugin_name)
 {
   const gchar *dpath = MUTTER_PLUGIN_DIR "/";
-  GSList      *plugins, *fallback = NULL;
+  gchar       *path;
+  MetaModule  *module;
+  GType        plugin_type;
+  MetaPlugin  *plugin;
 
-  if (plugin_mgr->plugin_load_attempted)
-    return TRUE;
-  plugin_mgr->plugin_load_attempted = TRUE;
-
-  plugins = meta_prefs_get_clutter_plugins ();
+  if (g_path_is_absolute (plugin_name))
+    path = g_strdup (plugin_name);
+  else
+    path = g_strconcat (dpath, plugin_name, ".so", NULL);
 
-  if (!plugins)
+  module = g_object_new (META_TYPE_MODULE, "path", path, NULL);
+  if (!module || !g_type_module_use (G_TYPE_MODULE (module)))
     {
-      /*
-       * If no plugins are specified, try to load the default plugin.
+      /* This is fatal under the assumption that a monitoring
+       * process like gnome-session will take over and handle
+       * our untimely exit.
        */
-      fallback = g_slist_append (fallback, "default");
-      plugins = fallback;
-    }
-
-  while (plugins)
-    {
-      gchar   *plugin_string;
-      gchar   *params;
-
-      plugin_string = g_strdup (plugins->data);
-
-      if (plugin_string)
-        {
-          MetaModule *module;
-          gchar        *path;
-
-          params = strchr (plugin_string, ':');
-
-          if (params)
-            {
-              *params = 0;
-              ++params;
-            }
-
-          if (g_path_is_absolute (plugin_string))
-            path = g_strdup (plugin_string);
-          else
-            path = g_strconcat (dpath, plugin_string, ".so", NULL);
-
-          module = meta_plugin_manager_get_module (path);
-
-          if (module)
-            {
-              gboolean      use_succeeded;
-
-              /*
-               * This dlopens the module and registers the plugin type with the
-               * GType system, if the module is not already loaded.  When we
-               * create a plugin, the type system also calls g_type_module_use()
-               * to guarantee the module will not be unloaded during the plugin
-               * life time. Consequently we can unuse() the module again.
-               */
-              use_succeeded = g_type_module_use (G_TYPE_MODULE (module));
-
-              if (use_succeeded)
-                {
-                  MetaPlugin *plugin = meta_plugin_load (plugin_mgr, module, params);
-
-                  if (plugin)
-                    plugin_mgr->plugins = g_list_prepend (plugin_mgr->plugins, plugin);
-                  else
-                    g_warning ("Plugin load for [%s] failed", path);
-
-                  g_type_module_unuse (G_TYPE_MODULE (module));
-                }
-            }
-          else
-            {
-              /* This is fatal under the assumption that a monitoring
-               * process like gnome-session will take over and handle
-               * our untimely exit.
-               */
-              g_printerr ("Unable to load plugin module [%s]: %s",
-                          path, g_module_error());
-              exit (1);
-            }
-
-          g_free (path);
-          g_free (plugin_string);
-        }
-
-      plugins = plugins->next;
+      g_printerr ("Unable to load plugin module [%s]: %s",
+                  path, g_module_error());
+      exit (1);
     }
 
+  plugin_type = meta_module_get_plugin_type (module);
+  plugin_types = g_slist_prepend (plugin_types, GSIZE_TO_POINTER (plugin_type));
 
-  if (fallback)
-    g_slist_free (fallback);
+  plugin = g_object_new (plugin_type, NULL);
+  plugin_mgr->plugins = g_list_prepend (plugin_mgr->plugins, plugin);
 
-  if (plugin_mgr->plugins != NULL)
-    {
-      meta_prefs_add_listener (prefs_changed_callback, plugin_mgr);
-      return TRUE;
-    }
-
-  return FALSE;
+  g_type_module_unuse (G_TYPE_MODULE (module));
+  g_free (path);
 }
 
-/**
- * meta_plugin_manager_initialize_early:
- * @plugin_mgr: a #MetaPluginManager
- *
- * This function invokes any plugin handling code that needs to be run
- * effectively immediately after we know which plugins are going to be
- * used.  This means before the process has an X connection, or
- * talks to the session manager, for example.
- *
- * An example intended use is claiming DBus names.
- */
-gboolean
-meta_plugin_manager_initialize_early (MetaPluginManager *plugin_mgr)
+void
+meta_plugin_manager_initialize (MetaPluginManager *plugin_mgr)
 {
   GList *iter;
 
-  for (iter = plugin_mgr->plugins; iter; iter = iter->next)
+  if (!plugin_mgr->plugins)
     {
-      MetaPlugin *plugin = (MetaPlugin*) iter->data;
-      MetaPluginClass *klass = META_PLUGIN_GET_CLASS (plugin);
-
-      if (klass->early_initialize)
-        klass->early_initialize (plugin);
+      /*
+       * If no plugins are specified, load the default plugin.
+       */
+      meta_plugin_manager_load (plugin_mgr, "default");
     }
 
-  return TRUE;
-}
-
-gboolean
-meta_plugin_manager_initialize (MetaPluginManager *plugin_mgr)
-{
-  GList *iter;
-
   for (iter = plugin_mgr->plugins; iter; iter = iter->next)
     {
       MetaPlugin *plugin = (MetaPlugin*) iter->data;
@@ -365,26 +117,6 @@ meta_plugin_manager_initialize (MetaPluginManager *plugin_mgr)
       if (klass->start)
         klass->start (plugin);
     }
-
-  return TRUE;
-}
-
-/*
- * Reloads all plugins
- */
-static gboolean
-meta_plugin_manager_reload (MetaPluginManager *plugin_mgr)
-{
-  /* TODO -- brute force; should we build a list of plugins to load and list of
-   * plugins to unload? We are probably not going to have large numbers of
-   * plugins loaded at the same time, so it might not be worth it.
-   */
-
-  /* Prevent stale grabs on unloaded plugins */
-  meta_check_end_modal (plugin_mgr->screen);
-
-  meta_plugin_manager_unload (plugin_mgr);
-  return meta_plugin_manager_load (plugin_mgr);
 }
 
 static MetaPluginManager *
@@ -392,15 +124,8 @@ meta_plugin_manager_new (MetaScreen *screen)
 {
   MetaPluginManager *plugin_mgr;
 
-  if (!plugin_modules)
-    {
-      plugin_modules = g_hash_table_new_full (g_str_hash, g_str_equal, g_free,
-                                              NULL);
-    }
-
   plugin_mgr = g_new0 (MetaPluginManager, 1);
-
-  plugin_mgr->screen        = screen;
+  plugin_mgr->screen = screen;
 
   if (screen)
     g_object_set_data (G_OBJECT (screen), "meta-plugin-manager", plugin_mgr);
@@ -441,7 +166,20 @@ meta_plugin_manager_get (MetaScreen *screen)
     }
   else
     {
-      return meta_plugin_manager_new (screen);
+      GSList *iter;
+      GType plugin_type;
+      MetaPlugin *plugin;
+
+      plugin_mgr = meta_plugin_manager_new (screen);
+
+      for (iter = plugin_types; iter; iter = iter->next)
+        {
+          plugin_type = (GType)GPOINTER_TO_SIZE (iter->data);
+          plugin = g_object_new (plugin_type, "screen", screen,  NULL);
+          plugin_mgr->plugins = g_list_prepend (plugin_mgr->plugins, plugin);
+        }
+
+      return plugin_mgr;
     }
 }