glib/gobject/gtypemodule.c
changeset 18 47c74d1534e1
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/glib/gobject/gtypemodule.c	Fri Apr 16 16:46:38 2010 +0300
@@ -0,0 +1,610 @@
+/* GObject - GLib Type, Object, Parameter and Signal Library
+ * Copyright (C) 2000 Red Hat, Inc.
+ * Portions copyright (c) 2006-2009 Nokia Corporation.  All rights reserved.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ */
+
+#include "config.h"
+
+#include <stdlib.h>
+
+#include "gtypeplugin.h"
+#include "gtypemodule.h"
+#include "gobjectalias.h"
+
+#ifdef __SYMBIAN32__
+#include "gobject_wsd.h"
+#endif /* __SYMBIAN32__ */
+/**
+ * SECTION:gtypemodule
+ * @short_description: Type loading modules
+ * @see_also:<variablelist>
+ * <varlistentry>
+ * <term>#GTypePlugin</term>
+ * <listitem><para>The abstract type loader interface.</para></listitem>
+ * </varlistentry>
+ * <varlistentry>
+ * <term>#GModule</term>
+ * <listitem><para>Portable mechanism for dynamically loaded modules.</para></listitem>
+ * </varlistentry>
+ * </variablelist>
+ * @title: GTypeModule
+ *
+ * #GTypeModule provides a simple implementation of the #GTypePlugin
+ * interface. The model of #GTypeModule is a dynamically loaded module
+ * which implements some number of types and interface
+ * implementations. When the module is loaded, it registers its types
+ * and interfaces using g_type_module_register_type() and
+ * g_type_module_add_interface().  As long as any instances of these
+ * types and interface implementations are in use, the module is kept
+ * loaded. When the types and interfaces are gone, the module may be
+ * unloaded. If the types and interfaces become used again, the module
+ * will be reloaded. Note that the last unref can not happen in module
+ * code, since that would lead to the caller's code being unloaded before
+ * g_object_unref() returns to it.
+ *
+ * Keeping track of whether the module should be loaded or not is done by
+ * using a use count - it starts at zero, and whenever it is greater than
+ * zero, the module is loaded. The use count is maintained internally by
+ * the type system, but also can be explicitly controlled by
+ * g_type_module_use() and g_type_module_unuse(). Typically, when loading
+ * a module for the first type, g_type_module_use() will be used to load
+ * it so that it can initialize its types. At some later point, when the
+ * module no longer needs to be loaded except for the type
+ * implementations it contains, g_type_module_unuse() is called.
+ *
+ * #GTypeModule does not actually provide any implementation of module
+ * loading and unloading. To create a particular module type you must
+ * derive from #GTypeModule and implement the load and unload functions
+ * in #GTypeModuleClass.
+ */
+
+
+typedef struct _ModuleTypeInfo ModuleTypeInfo;
+typedef struct _ModuleInterfaceInfo ModuleInterfaceInfo;
+
+struct _ModuleTypeInfo 
+{
+  gboolean  loaded;
+  GType     type;
+  GType     parent_type;
+  GTypeInfo info;
+};
+
+struct _ModuleInterfaceInfo 
+{
+  gboolean       loaded;
+  GType          instance_type;
+  GType          interface_type;
+  GInterfaceInfo info;
+};
+
+static void g_type_module_use_plugin              (GTypePlugin     *plugin);
+static void g_type_module_complete_type_info      (GTypePlugin     *plugin,
+						   GType            g_type,
+						   GTypeInfo       *info,
+						   GTypeValueTable *value_table);
+static void g_type_module_complete_interface_info (GTypePlugin     *plugin,
+						   GType            instance_type,
+						   GType            interface_type,
+						   GInterfaceInfo  *info);
+
+#if EMULATOR
+
+PLS(parent_class ,gtypemodule,gpointer)
+#define parent_class  (*FUNCTION_NAME(parent_class,gtypemodule)())
+
+#else
+ 
+static gpointer parent_class = NULL;
+
+#endif /* EMULATOR*/
+static void
+g_type_module_dispose (GObject *object)
+{
+  GTypeModule *module = G_TYPE_MODULE (object);
+  
+  if (module->type_infos || module->interface_infos)
+    {
+      g_warning (G_STRLOC ": unsolicitated invocation of g_object_dispose() on GTypeModule");
+	     
+      g_object_ref (object);
+    }
+
+  G_OBJECT_CLASS (parent_class)->dispose (object);
+}
+
+static void
+g_type_module_finalize (GObject *object)
+{
+  GTypeModule *module = G_TYPE_MODULE (object);
+
+  g_free (module->name);
+
+  G_OBJECT_CLASS (parent_class)->finalize (object);
+}
+
+static void
+g_type_module_class_init (GTypeModuleClass *class)
+{
+  GObjectClass *gobject_class = G_OBJECT_CLASS (class);
+
+  parent_class = G_OBJECT_CLASS (g_type_class_peek_parent (class));
+  
+  gobject_class->dispose = g_type_module_dispose;
+  gobject_class->finalize = g_type_module_finalize;
+}
+
+static void
+g_type_module_iface_init (GTypePluginClass *iface)
+{
+  iface->use_plugin = g_type_module_use_plugin;
+  iface->unuse_plugin = (void (*) (GTypePlugin *))g_type_module_unuse;
+  iface->complete_type_info = g_type_module_complete_type_info;
+  iface->complete_interface_info = g_type_module_complete_interface_info;
+}
+
+#if EMULATOR
+
+PLS(type_module_type,g_type_module_get_type ,GType)
+#define type_module_type (*FUNCTION_NAME(type_module_type,g_type_module_get_type )())
+
+#endif /* EMULATOR */
+
+EXPORT_C GType
+g_type_module_get_type (void)
+{
+  #if !(EMULATOR)
+  static GType type_module_type = 0;
+  #endif /* EMULATOR */
+
+  if (!type_module_type)
+    {
+      static const GTypeInfo type_module_info = {
+        sizeof (GTypeModuleClass),
+        NULL,           /* base_init */
+        NULL,           /* base_finalize */
+        (GClassInitFunc) g_type_module_class_init,
+        NULL,           /* class_finalize */
+        NULL,           /* class_data */
+        sizeof (GTypeModule),
+        0,              /* n_preallocs */
+        NULL,           /* instance_init */
+      };
+      static const GInterfaceInfo iface_info = {
+        (GInterfaceInitFunc) g_type_module_iface_init,
+        NULL,               /* interface_finalize */
+        NULL,               /* interface_data */
+      };
+
+      type_module_type = g_type_register_static (G_TYPE_OBJECT, g_intern_static_string ("GTypeModule"), &type_module_info, G_TYPE_FLAG_ABSTRACT);
+
+      g_type_add_interface_static (type_module_type, G_TYPE_TYPE_PLUGIN, &iface_info);
+    }
+  
+  return type_module_type;
+}
+
+#if EMULATOR
+#undef  type_module_type
+#endif /* EMULATOR */
+
+/**
+ * g_type_module_set_name:
+ * @module: a #GTypeModule.
+ * @name: a human-readable name to use in error messages.
+ * 
+ * Sets the name for a #GTypeModule 
+ */
+EXPORT_C void
+g_type_module_set_name (GTypeModule  *module,
+			const gchar  *name)
+{
+  g_return_if_fail (G_IS_TYPE_MODULE (module));
+
+  g_free (module->name);
+  module->name = g_strdup (name);
+}
+
+static ModuleTypeInfo *
+g_type_module_find_type_info (GTypeModule *module,
+			      GType        type)
+{
+  GSList *tmp_list = module->type_infos;
+  while (tmp_list)
+    {
+      ModuleTypeInfo *type_info = tmp_list->data;
+      if (type_info->type == type)
+	return type_info;
+      
+      tmp_list = tmp_list->next;
+    }
+
+  return NULL;
+}
+
+static ModuleInterfaceInfo *
+g_type_module_find_interface_info (GTypeModule *module,
+				   GType        instance_type,
+				   GType        interface_type)
+{
+  GSList *tmp_list = module->interface_infos;
+  while (tmp_list)
+    {
+      ModuleInterfaceInfo *interface_info = tmp_list->data;
+      if (interface_info->instance_type == instance_type &&
+	  interface_info->interface_type == interface_type)
+	return interface_info;
+      
+      tmp_list = tmp_list->next;
+    }
+
+  return NULL;
+}
+
+/**
+ * g_type_module_use:
+ * @module: a #GTypeModule
+ * 
+ * Increases the use count of a #GTypeModule by one. If the
+ * use count was zero before, the plugin will be loaded.
+ * If loading the plugin fails, the use count is reset to 
+ * its prior value. 
+ * 
+ * Returns: %FALSE if the plugin needed to be loaded and
+ *  loading the plugin failed.
+ */
+EXPORT_C gboolean
+g_type_module_use (GTypeModule *module)
+{
+  g_return_val_if_fail (G_IS_TYPE_MODULE (module), FALSE);
+
+  module->use_count++;
+  if (module->use_count == 1)
+    {
+      GSList *tmp_list;
+      
+      if (!G_TYPE_MODULE_GET_CLASS (module)->load (module))
+	{
+	  module->use_count--;
+	  return FALSE;
+	}
+
+      tmp_list = module->type_infos;
+      while (tmp_list)
+	{
+	  ModuleTypeInfo *type_info = tmp_list->data;
+	  if (!type_info->loaded)
+	    {
+	      g_warning ("plugin '%s' failed to register type '%s'\n",
+			 module->name ? module->name : "(unknown)",
+			 g_type_name (type_info->type));
+	      module->use_count--;
+	      return FALSE;
+	    }
+	  
+	  tmp_list = tmp_list->next;
+	}
+    }
+ 
+  return TRUE;
+}
+
+/**
+ * g_type_module_unuse:
+ * @module: a #GTypeModule
+ *
+ * Decreases the use count of a #GTypeModule by one. If the
+ * result is zero, the module will be unloaded. (However, the
+ * #GTypeModule will not be freed, and types associated with the
+ * #GTypeModule are not unregistered. Once a #GTypeModule is
+ * initialized, it must exist forever.)
+ */
+EXPORT_C void
+g_type_module_unuse (GTypeModule *module)
+{
+  g_return_if_fail (G_IS_TYPE_MODULE (module));
+  g_return_if_fail (module->use_count > 0);
+
+  module->use_count--;
+
+  if (module->use_count == 0)
+    {
+      GSList *tmp_list;
+
+      G_TYPE_MODULE_GET_CLASS (module)->unload (module);
+
+      tmp_list = module->type_infos;
+      while (tmp_list)
+	{
+	  ModuleTypeInfo *type_info = tmp_list->data;
+	  type_info->loaded = FALSE;
+
+	  tmp_list = tmp_list->next;
+	}
+    }
+}
+	
+static void
+g_type_module_use_plugin (GTypePlugin *plugin)
+{
+  GTypeModule *module = G_TYPE_MODULE (plugin);
+
+  if (!g_type_module_use (module))
+    {
+      g_warning ("Fatal error - Could not reload previously loaded plugin '%s'\n",
+		 module->name ? module->name : "(unknown)");
+      exit (1);
+    }
+}
+
+static void
+g_type_module_complete_type_info (GTypePlugin     *plugin,
+				  GType            g_type,
+				  GTypeInfo       *info,
+				  GTypeValueTable *value_table)
+{
+  GTypeModule *module = G_TYPE_MODULE (plugin);
+  ModuleTypeInfo *module_type_info = g_type_module_find_type_info (module, g_type);
+
+  *info = module_type_info->info;
+  
+  if (module_type_info->info.value_table)
+    *value_table = *module_type_info->info.value_table;
+}
+
+static void 
+g_type_module_complete_interface_info (GTypePlugin    *plugin,
+				       GType           instance_type,
+				       GType           interface_type,
+				       GInterfaceInfo *info)
+{
+  GTypeModule *module = G_TYPE_MODULE (plugin);
+  ModuleInterfaceInfo *module_interface_info = g_type_module_find_interface_info (module, instance_type, interface_type);
+
+  *info = module_interface_info->info;
+}
+
+/**
+ * g_type_module_register_type:
+ * @module: a #GTypeModule
+ * @parent_type: the type for the parent class
+ * @type_name: name for the type
+ * @type_info: type information structure
+ * @flags: flags field providing details about the type
+ *
+ * Looks up or registers a type that is implemented with a particular
+ * type plugin. If a type with name @type_name was previously registered,
+ * the #GType identifier for the type is returned, otherwise the type
+ * is newly registered, and the resulting #GType identifier returned.
+ *
+ * When reregistering a type (typically because a module is unloaded
+ * then reloaded, and reinitialized), @module and @parent_type must
+ * be the same as they were previously.
+ *
+ * As long as any instances of the type exist, the type plugin will
+ * not be unloaded.
+ *
+ * Returns: the new or existing type ID
+ */
+EXPORT_C GType
+g_type_module_register_type (GTypeModule     *module,
+			     GType            parent_type,
+			     const gchar     *type_name,
+			     const GTypeInfo *type_info,
+			     GTypeFlags       flags)
+{
+  ModuleTypeInfo *module_type_info = NULL;
+  GType type;
+  
+  g_return_val_if_fail (module != NULL, 0);
+  g_return_val_if_fail (type_name != NULL, 0);
+  g_return_val_if_fail (type_info != NULL, 0);
+
+  type = g_type_from_name (type_name);
+  if (type)
+    {
+      GTypePlugin *old_plugin = g_type_get_plugin (type);
+
+      if (old_plugin != G_TYPE_PLUGIN (module))
+	{
+	  g_warning ("Two different plugins tried to register '%s'.", type_name);
+	  return 0;
+	}
+    }
+
+  if (type)
+    {
+      module_type_info = g_type_module_find_type_info (module, type);
+
+      if (module_type_info->parent_type != parent_type)
+	{
+	  const gchar *parent_type_name = g_type_name (parent_type);
+	  
+	  g_warning ("Type '%s' recreated with different parent type.\n"
+		     "(was '%s', now '%s')", type_name,
+		     g_type_name (module_type_info->parent_type),
+		     parent_type_name ? parent_type_name : "(unknown)");
+	  return 0;
+	}
+
+      if (module_type_info->info.value_table)
+	g_free ((GTypeValueTable *) module_type_info->info.value_table);
+    }
+  else
+    {
+      module_type_info = g_new (ModuleTypeInfo, 1);
+      
+      module_type_info->parent_type = parent_type;
+      module_type_info->type = g_type_register_dynamic (parent_type, type_name, G_TYPE_PLUGIN (module), flags);
+      
+      module->type_infos = g_slist_prepend (module->type_infos, module_type_info);
+    }
+
+  module_type_info->loaded = TRUE;
+  module_type_info->info = *type_info;
+  if (type_info->value_table)
+    module_type_info->info.value_table = g_memdup (type_info->value_table,
+						   sizeof (GTypeValueTable));
+
+  return module_type_info->type;
+}
+
+/**
+ * g_type_module_add_interface:
+ * @module: a #GTypeModule
+ * @instance_type: type to which to add the interface.
+ * @interface_type: interface type to add
+ * @interface_info: type information structure
+ *
+ * Registers an additional interface for a type, whose interface lives
+ * in the given type plugin. If the interface was already registered
+ * for the type in this plugin, nothing will be done.
+ *
+ * As long as any instances of the type exist, the type plugin will
+ * not be unloaded.
+ */
+EXPORT_C void
+g_type_module_add_interface (GTypeModule          *module,
+			     GType                 instance_type,
+			     GType                 interface_type,
+			     const GInterfaceInfo *interface_info)
+{
+  ModuleInterfaceInfo *module_interface_info = NULL;
+  
+  g_return_if_fail (module != NULL);
+  g_return_if_fail (interface_info != NULL);
+
+  if (g_type_is_a (instance_type, interface_type))
+    {
+      GTypePlugin *old_plugin = g_type_interface_get_plugin (instance_type,
+							     interface_type);
+
+      if (!old_plugin)
+	{
+	  g_warning ("Interface '%s' for '%s' was previously registered statically or for a parent type.",
+		     g_type_name (interface_type), g_type_name (instance_type));
+	  return;
+	}
+      else if (old_plugin != G_TYPE_PLUGIN (module))
+	{
+	  g_warning ("Two different plugins tried to register interface '%s' for '%s'.",
+		     g_type_name (interface_type), g_type_name (instance_type));
+	  return;
+	}
+      
+      module_interface_info = g_type_module_find_interface_info (module, instance_type, interface_type);
+
+      g_assert (module_interface_info);
+    }
+  else
+    {
+      module_interface_info = g_new (ModuleInterfaceInfo, 1);
+      
+      module_interface_info->instance_type = instance_type;
+      module_interface_info->interface_type = interface_type;
+      
+      g_type_add_interface_dynamic (instance_type, interface_type, G_TYPE_PLUGIN (module));
+      
+      module->interface_infos = g_slist_prepend (module->interface_infos, module_interface_info);
+    }
+  
+  module_interface_info->loaded = TRUE;
+  module_interface_info->info = *interface_info;
+}
+
+/**
+ * g_type_module_register_enum:
+ * @module: a #GTypeModule
+ * @name: name for the type
+ * @const_static_values: an array of #GEnumValue structs for the
+ *                       possible enumeration values. The array is
+ *                       terminated by a struct with all members being
+ *                       0.
+ *
+ * Looks up or registers an enumeration that is implemented with a particular
+ * type plugin. If a type with name @type_name was previously registered,
+ * the #GType identifier for the type is returned, otherwise the type
+ * is newly registered, and the resulting #GType identifier returned.
+ *
+ * As long as any instances of the type exist, the type plugin will
+ * not be unloaded.
+ *
+ * Since: 2.6
+ *
+ * Returns: the new or existing type ID
+ */
+EXPORT_C GType
+g_type_module_register_enum (GTypeModule      *module,
+                             const gchar      *name,
+                             const GEnumValue *const_static_values)
+{
+  GTypeInfo enum_type_info = { 0, };
+
+  g_return_val_if_fail (G_IS_TYPE_MODULE (module), 0);
+  g_return_val_if_fail (name != NULL, 0);
+  g_return_val_if_fail (const_static_values != NULL, 0);
+
+  g_enum_complete_type_info (G_TYPE_ENUM,
+                             &enum_type_info, const_static_values);
+
+  return g_type_module_register_type (G_TYPE_MODULE (module),
+                                      G_TYPE_ENUM, name, &enum_type_info, 0);
+}
+
+/**
+ * g_type_module_register_flags:
+ * @module: a #GTypeModule
+ * @name: name for the type
+ * @const_static_values: an array of #GFlagsValue structs for the
+ *                       possible flags values. The array is
+ *                       terminated by a struct with all members being
+ *                       0.
+ *
+ * Looks up or registers a flags type that is implemented with a particular
+ * type plugin. If a type with name @type_name was previously registered,
+ * the #GType identifier for the type is returned, otherwise the type
+ * is newly registered, and the resulting #GType identifier returned.
+ *
+ * As long as any instances of the type exist, the type plugin will
+ * not be unloaded.
+ *
+ * Since: 2.6
+ *
+ * Returns: the new or existing type ID
+ */
+EXPORT_C GType
+g_type_module_register_flags (GTypeModule      *module,
+                             const gchar       *name,
+                             const GFlagsValue *const_static_values)
+{
+  GTypeInfo flags_type_info = { 0, };
+
+  g_return_val_if_fail (G_IS_TYPE_MODULE (module), 0);
+  g_return_val_if_fail (name != NULL, 0);
+  g_return_val_if_fail (const_static_values != NULL, 0);
+
+  g_flags_complete_type_info (G_TYPE_FLAGS,
+                             &flags_type_info, const_static_values);
+
+  return g_type_module_register_type (G_TYPE_MODULE (module),
+                                      G_TYPE_FLAGS, name, &flags_type_info, 0);
+}
+
+
+#define __G_TYPE_MODULE_C__
+#include "gobjectaliasdef.c"