/* GObject - GLib Type, Object, Parameter and Signal Library
* Copyright (C) 2000 Red Hat, Inc.
*
* 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 2.1 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, see <http://www.gnu.org/licenses/>.
*/
#include "config.h"
#include <stdlib.h>
#include "gtypeplugin.h"
#include "gtypemodule.h"
/**
* SECTION:gtypemodule
* @short_description: Type loading modules
* @see_also: #GTypePlugin, #GModule
* @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 cannot 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);
static gpointer parent_class = NULL;
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_run_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;
}
GType
g_type_module_get_type (void)
{
static GType type_module_type = 0;
if (!type_module_type)
{
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 */
};
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;
}
/**
* g_type_module_set_name:
* @module: a #GTypeModule.
* @name: a human-readable name to use in error messages.
*
* Sets the name for a #GTypeModule
*/
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.
*/
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.)
*/
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: (nullable): 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.
*
* Since 2.56 if @module is %NULL this will call g_type_register_static()
* instead. This can be used when making a static build of the module.
*
* Returns: the new or existing type ID
*/
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 (type_name != NULL, 0);
g_return_val_if_fail (type_info != NULL, 0);
if (module == NULL)
{
/* Cannot pass type_info directly to g_type_register_static() here because
* it has class_finalize != NULL and that's forbidden for static types */
return g_type_register_static_simple (parent_type,
type_name,
type_info->class_size,
type_info->class_init,
type_info->instance_size,
type_info->instance_init,
flags);
}
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: (nullable): 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.
*
* Since 2.56 if @module is %NULL this will call g_type_add_interface_static()
* instead. This can be used when making a static build of the module.
*/
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 (interface_info != NULL);
if (module == NULL)
{
g_type_add_interface_static (instance_type, interface_type, interface_info);
return;
}
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: (nullable): 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 2.56 if @module is %NULL this will call g_type_register_static()
* instead. This can be used when making a static build of the module.
*
* Since: 2.6
*
* Returns: the new or existing type ID
*/
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 (module == NULL || 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: (nullable): 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 2.56 if @module is %NULL this will call g_type_register_static()
* instead. This can be used when making a static build of the module.
*
* Since: 2.6
*
* Returns: the new or existing type ID
*/
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 (module == NULL || 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);
}