gobject/gtypemodule.c

   1 /* GObject - GLib Type, Object, Parameter and Signal Library
   2  * Copyright (C) 2000 Red Hat, Inc.
   3  *
   4  * This library is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU Lesser General Public
   6  * License as published by the Free Software Foundation; either
   7  * version 2 of the License, or (at your option) any later version.
   8  *
   9  * This library is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  * Lesser General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU Lesser General Public
  15  * License along with this library; if not, write to the
  16  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  17  * Boston, MA 02111-1307, USA.
  18  */
  19
  20 #include <stdlib.h>
  21
  22 #include "gtypeplugin.h"
  23 #include "gtypemodule.h"
  24
  25 typedef struct _ModuleTypeInfo ModuleTypeInfo;
  26 typedef struct _ModuleInterfaceInfo ModuleInterfaceInfo;
  27
  28 struct _ModuleTypeInfo
  29 {
  30   gboolean  loaded;
  31   GType     type;
  32   GType     parent_type;
  33   GTypeInfo info;
  34 };
  35
  36 struct _ModuleInterfaceInfo
  37 {
  38   gboolean       loaded;
  39   GType          instance_type;
  40   GType          interface_type;
  41   GInterfaceInfo info;
  42 };
  43
  44 static void g_type_module_use_plugin              (GTypePlugin     *plugin);
  45 static void g_type_module_complete_type_info      (GTypePlugin     *plugin,
  46                                                    GType            g_type,
  47                                                    GTypeInfo       *info,
  48                                                    GTypeValueTable *value_table);
  49 static void g_type_module_complete_interface_info (GTypePlugin     *plugin,
  50                                                    GType            instance_type,
  51                                                    GType            interface_type,
  52                                                    GInterfaceInfo  *info);
  53
  54 static gpointer parent_class = NULL;
  55
  56 static void
  57 g_type_module_dispose (GObject *object)
  58 {
  59   GTypeModule *module = G_TYPE_MODULE (object);
  60
  61   if (module->type_infos || module->interface_infos)
  62     {
  63       g_warning (G_STRLOC ": unsolicitated invocation of g_object_dispose() on GTypeModule");
  64
  65       g_object_ref (object);
  66     }
  67
  68   G_OBJECT_CLASS (parent_class)->dispose (object);
  69 }
  70
  71 static void
  72 g_type_module_finalize (GObject *object)
  73 {
  74   GTypeModule *module = G_TYPE_MODULE (object);
  75
  76   g_free (module->name);
  77
  78   G_OBJECT_CLASS (parent_class)->finalize (object);
  79 }
  80
  81 static void
  82 g_type_module_class_init (GTypeModuleClass *class)
  83 {
  84   GObjectClass *gobject_class = G_OBJECT_CLASS (class);
  85
  86   parent_class = G_OBJECT_CLASS (g_type_class_peek_parent (class));
  87
  88   gobject_class->dispose = g_type_module_dispose;
  89   gobject_class->finalize = g_type_module_finalize;
  90 }
  91
  92 static void
  93 g_type_module_iface_init (GTypePluginClass *iface)
  94 {
  95   iface->use_plugin = g_type_module_use_plugin;
  96   iface->unuse_plugin = (void (*) (GTypePlugin *))g_type_module_unuse;
  97   iface->complete_type_info = g_type_module_complete_type_info;
  98   iface->complete_interface_info = g_type_module_complete_interface_info;
  99 }
 100
 101 GType
 102 g_type_module_get_type (void)
 103 {
 104   static GType type_module_type = 0;
 105
 106   if (!type_module_type)
 107     {
 108       static const GTypeInfo type_module_info = {
 109         sizeof (GTypeModuleClass),
 110         NULL,           /* base_init */
 111         NULL,           /* base_finalize */
 112         (GClassInitFunc) g_type_module_class_init,
 113         NULL,           /* class_finalize */
 114         NULL,           /* class_data */
 115         sizeof (GTypeModule),
 116         0,              /* n_preallocs */
 117         NULL,           /* instance_init */
 118       };
 119       static const GInterfaceInfo iface_info = {
 120         (GInterfaceInitFunc) g_type_module_iface_init,
 121         NULL,               /* interface_finalize */
 122         NULL,               /* interface_data */
 123       };
 124
 125       type_module_type = g_type_register_static (G_TYPE_OBJECT, "GTypeModule", &type_module_info, G_TYPE_FLAG_ABSTRACT);
 126
 127       g_type_add_interface_static (type_module_type, G_TYPE_TYPE_PLUGIN, &iface_info);
 128     }
 129
 130   return type_module_type;
 131 }
 132
 133 /**
 134  * g_type_module_set_name
 135  * @module: a #GTypeModule.
 136  * @name: a human-readable name to use in error messages.
 137  *
 138  * Sets the name for a #GTypeModule
 139  **/
 140 void
 141 g_type_module_set_name (GTypeModule  *module,
 142                         const gchar  *name)
 143 {
 144   g_return_if_fail (G_IS_TYPE_MODULE (module));
 145
 146   g_free (module->name);
 147   module->name = g_strdup (name);
 148 }
 149
 150 static ModuleTypeInfo *
 151 g_type_module_find_type_info (GTypeModule *module,
 152                               GType        type)
 153 {
 154   GSList *tmp_list = module->type_infos;
 155   while (tmp_list)
 156     {
 157       ModuleTypeInfo *type_info = tmp_list->data;
 158       if (type_info->type == type)
 159         return type_info;
 160
 161       tmp_list = tmp_list->next;
 162     }
 163
 164   return NULL;
 165 }
 166
 167 static ModuleInterfaceInfo *
 168 g_type_module_find_interface_info (GTypeModule *module,
 169                                    GType        instance_type,
 170                                    GType        interface_type)
 171 {
 172   GSList *tmp_list = module->interface_infos;
 173   while (tmp_list)
 174     {
 175       ModuleInterfaceInfo *interface_info = tmp_list->data;
 176       if (interface_info->instance_type == instance_type &&
 177           interface_info->interface_type == interface_type)
 178         return interface_info;
 179
 180       tmp_list = tmp_list->next;
 181     }
 182
 183   return NULL;
 184 }
 185
 186 /**
 187  * g_type_module_use:
 188  * @module: a #GTypeModule
 189  *
 190  * Increases the use count of a #GTypeModule by one. If the
 191  * use count was zero before, the plugin will be loaded.
 192  *
 193  * Return Value: %FALSE if the plugin needed to be loaded and
 194  *               loading the plugin failed.
 195  **/
 196 gboolean
 197 g_type_module_use (GTypeModule *module)
 198 {
 199   g_return_val_if_fail (G_IS_TYPE_MODULE (module), FALSE);
 200
 201   module->use_count++;
 202   if (module->use_count == 1)
 203     {
 204       GSList *tmp_list;
 205
 206       if (!G_TYPE_MODULE_GET_CLASS (module)->load (module))
 207         {
 208           module->use_count--;
 209           return FALSE;
 210         }
 211
 212       tmp_list = module->type_infos;
 213       while (tmp_list)
 214         {
 215           ModuleTypeInfo *type_info = tmp_list->data;
 216           if (!type_info->loaded)
 217             {
 218               g_warning ("plugin '%s' failed to register type '%s'\n",
 219                          module->name ? module->name : "(unknown)",
 220                          g_type_name (type_info->type));
 221               return FALSE;
 222             }
 223
 224           tmp_list = tmp_list->next;
 225         }
 226     }
 227
 228   return TRUE;
 229 }
 230
 231 /**
 232  * g_type_module_unuse:
 233  * @module: a #GTypeModule
 234  *
 235  * Decreases the use count of a #GTypeModule by one. If the
 236  * result is zero, the module will be unloaded. (However, the
 237  * #GTypeModule will not be freed, and types associated with the
 238  * #GTypeModule are not unregistered. Once a #GTypeModule is
 239  * initialized, it must exist forever.)
 240  **/
 241 void
 242 g_type_module_unuse (GTypeModule *module)
 243 {
 244   g_return_if_fail (G_IS_TYPE_MODULE (module));
 245   g_return_if_fail (module->use_count > 0);
 246
 247   module->use_count--;
 248
 249   if (module->use_count == 0)
 250     {
 251       GSList *tmp_list;
 252
 253       G_TYPE_MODULE_GET_CLASS (module)->unload (module);
 254
 255       tmp_list = module->type_infos;
 256       while (tmp_list)
 257         {
 258           ModuleTypeInfo *type_info = tmp_list->data;
 259           type_info->loaded = FALSE;
 260
 261           tmp_list = tmp_list->next;
 262         }
 263     }
 264 }
 265
 266 static void
 267 g_type_module_use_plugin (GTypePlugin *plugin)
 268 {
 269   GTypeModule *module = G_TYPE_MODULE (plugin);
 270
 271   if (!g_type_module_use (module))
 272     {
 273       g_warning ("Fatal error - Could not reload previously loaded plugin '%s'\n",
 274                  module->name ? module->name : "(unknown)");
 275       exit (1);
 276     }
 277 }
 278
 279 static void
 280 g_type_module_complete_type_info (GTypePlugin     *plugin,
 281                                   GType            g_type,
 282                                   GTypeInfo       *info,
 283                                   GTypeValueTable *value_table)
 284 {
 285   GTypeModule *module = G_TYPE_MODULE (plugin);
 286   ModuleTypeInfo *module_type_info = g_type_module_find_type_info (module, g_type);
 287
 288   *info = module_type_info->info;
 289
 290   if (module_type_info->info.value_table)
 291     *value_table = *module_type_info->info.value_table;
 292 }
 293
 294 static void
 295 g_type_module_complete_interface_info (GTypePlugin    *plugin,
 296                                        GType           instance_type,
 297                                        GType           interface_type,
 298                                        GInterfaceInfo *info)
 299 {
 300   GTypeModule *module = G_TYPE_MODULE (plugin);
 301   ModuleInterfaceInfo *module_interface_info = g_type_module_find_interface_info (module, interface_type, instance_type);
 302
 303   *info = module_interface_info->info;
 304 }
 305
 306 /**
 307  * g_type_module_register_type:
 308  * @module:  a #GTypeModule
 309  * @parent_type:    the type for the parent class
 310  * @type_name:      name for the type
 311  * @type_info:      type information structure
 312  * @flags:          flags field providing details about the type
 313  *
 314  * Looks up or registers a type that is implemented with a particular
 315  * type plugin. If a type with name @type_name is already registered,
 316  * the #GType identifier for the type is returned, otherwise the type
 317  * is newly registered, and the resulting #GType identifier returned.
 318  *
 319  * As long as any instances of the type exist, the type plugin will
 320  * not be unloaded.
 321  *
 322  * Return value: the type ID for the class.
 323  **/
 324 GType
 325 g_type_module_register_type (GTypeModule     *module,
 326                              GType            parent_type,
 327                              const gchar     *type_name,
 328                              const GTypeInfo *type_info,
 329                              GTypeFlags       flags)
 330 {
 331   ModuleTypeInfo *module_type_info = NULL;
 332   GType type;
 333
 334   g_return_val_if_fail (module != NULL, 0);
 335   g_return_val_if_fail (type_name != NULL, 0);
 336   g_return_val_if_fail (type_info != NULL, 0);
 337
 338   type = g_type_from_name (type_name);
 339   if (type)
 340     {
 341       GTypePlugin *old_plugin = g_type_get_plugin (type);
 342
 343       if (old_plugin != G_TYPE_PLUGIN (module))
 344         {
 345           g_warning ("Two different plugins tried to register '%s'.", type_name);
 346           return 0;
 347         }
 348     }
 349
 350   if (type)
 351     {
 352       module_type_info = g_type_module_find_type_info (module, type);
 353
 354       if (module_type_info->parent_type != parent_type)
 355         {
 356           const gchar *parent_type_name = g_type_name (parent_type);
 357
 358           g_warning ("Type '%s' recreated with different parent type.\n"
 359                      "(was '%s', now '%s')", type_name,
 360                      g_type_name (module_type_info->parent_type),
 361                      parent_type_name ? parent_type_name : "(unknown)");
 362           return 0;
 363         }
 364     }
 365   else
 366     {
 367       module_type_info = g_new (ModuleTypeInfo, 1);
 368
 369       module_type_info->parent_type = parent_type;
 370       module_type_info->type = g_type_register_dynamic (parent_type, type_name, G_TYPE_PLUGIN (module), flags);
 371
 372       module->type_infos = g_slist_prepend (module->type_infos, module_type_info);
 373     }
 374
 375   module_type_info->loaded = TRUE;
 376   module_type_info->info = *type_info;
 377   if (type_info->value_table)
 378     module_type_info->info.value_table = g_memdup (type_info->value_table,
 379                                                    sizeof (type_info->value_table));
 380
 381   return module_type_info->type;
 382 }
 383
 384 /**
 385  * g_type_module_add_interface:
 386  * @module: a #GTypeModule
 387  * @instance_type: type to which to add the interface.
 388  * @interface_type: interface type to add
 389  * @interface_info: type information structure
 390  *
 391  * Registers an additional interface for a type, whose interface
 392  * lives in the given type plugin. If the interface was already registered
 393  * for the type in this plugin, nothing will be done.
 394  *
 395  * As long as any instances of the type exist, the type plugin will
 396  * not be unloaded.
 397  **/
 398 void
 399 g_type_module_add_interface (GTypeModule    *module,
 400                              GType           instance_type,
 401                              GType           interface_type,
 402                              GInterfaceInfo *interface_info)
 403 {
 404   ModuleInterfaceInfo *module_interface_info = NULL;
 405
 406   g_return_if_fail (module != NULL);
 407   g_return_if_fail (interface_info != NULL);
 408
 409   if (g_type_is_a (instance_type, interface_type))
 410     {
 411       GTypePlugin *old_plugin = g_type_interface_get_plugin (instance_type,
 412                                                              interface_type);
 413
 414       if (!old_plugin)
 415         {
 416           g_warning ("Interface '%s' for '%s' was previously registered statically or for a parent type.",
 417                      g_type_name (interface_type), g_type_name (instance_type));
 418           return;
 419         }
 420       else if (old_plugin != G_TYPE_PLUGIN (module))
 421         {
 422           g_warning ("Two different plugins tried to register interface '%s' for '%s'.",
 423                      g_type_name (interface_type), g_type_name (instance_type));
 424           return;
 425         }
 426
 427       module_interface_info = g_type_module_find_interface_info (module, instance_type, interface_type);
 428
 429       g_assert (module_interface_info);
 430     }
 431   else
 432     {
 433       module_interface_info = g_new (ModuleInterfaceInfo, 1);
 434
 435       module_interface_info->instance_type = instance_type;
 436       module_interface_info->interface_type = interface_type;
 437
 438       g_type_add_interface_dynamic (instance_type, interface_type, G_TYPE_PLUGIN (module));
 439
 440       module->interface_infos = g_slist_prepend (module->interface_infos, module_interface_info);
 441     }
 442
 443   module_interface_info->loaded = TRUE;
 444   module_interface_info->info = *interface_info;
 445 }