glib/gio/giomodule.c
Sebastian Dröge b4a5157f95 Fix compiler warning about uninitialized variable in giomodule
It could've never been uninitialized in this code but the code flow is
not obvious to the compiler. Initialize it to NULL and for clarity also
add an assertion that it is not NULL anymore on usage.

In file included from ../glib/glib.h:62,
                 from ../gobject/gbinding.h:28,
                 from ../glib/glib-object.h:23,
                 from ../gio/gioenums.h:28,
                 from ../gio/giotypes.h:28,
                 from ../gio/giomodule.h:28,
                 from ../gio/giomodule.c:25:
../gio/giomodule.c: In function ‘_g_io_module_get_default’:
../glib/gmessages.h:343:25: warning: ‘extension’ may be used uninitialized in this function [-Wmaybe-uninitialized]
 #define g_debug(...)    g_log (G_LOG_DOMAIN,         \
                         ^~~~~
../gio/giomodule.c:912:17: note: ‘extension’ was declared here
   GIOExtension *extension, *preferred;
                 ^~~~~~~~~
2019-01-24 16:35:13 +02:00

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/* GIO - GLib Input, Output and Streaming Library
*
* Copyright (C) 2006-2007 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/>.
*
* Author: Alexander Larsson <alexl@redhat.com>
*/
#include "config.h"
#include <string.h>
#include "giomodule.h"
#include "giomodule-priv.h"
#include "glocalfilemonitor.h"
#include "gnativevolumemonitor.h"
#include "gproxyresolver.h"
#include "gproxy.h"
#include "gsettingsbackendinternal.h"
#include "ghttpproxy.h"
#include "gsocks4proxy.h"
#include "gsocks4aproxy.h"
#include "gsocks5proxy.h"
#include "gtlsbackend.h"
#include "gvfs.h"
#include "gnotificationbackend.h"
#include "ginitable.h"
#include "gnetworkmonitor.h"
#ifdef G_OS_WIN32
#include "gregistrysettingsbackend.h"
#endif
#include <glib/gstdio.h>
#if defined(G_OS_UNIX) && !defined(HAVE_COCOA)
#include "gdesktopappinfo.h"
#endif
#ifdef HAVE_COCOA
#include "gosxappinfo.h"
#endif
#ifdef HAVE_COCOA
#include <AvailabilityMacros.h>
#endif
/**
* SECTION:giomodule
* @short_description: Loadable GIO Modules
* @include: gio/gio.h
*
* Provides an interface and default functions for loading and unloading
* modules. This is used internally to make GIO extensible, but can also
* be used by others to implement module loading.
*
**/
/**
* SECTION:extensionpoints
* @short_description: Extension Points
* @include: gio.h
* @see_also: [Extending GIO][extending-gio]
*
* #GIOExtensionPoint provides a mechanism for modules to extend the
* functionality of the library or application that loaded it in an
* organized fashion.
*
* An extension point is identified by a name, and it may optionally
* require that any implementation must be of a certain type (or derived
* thereof). Use g_io_extension_point_register() to register an
* extension point, and g_io_extension_point_set_required_type() to
* set a required type.
*
* A module can implement an extension point by specifying the #GType
* that implements the functionality. Additionally, each implementation
* of an extension point has a name, and a priority. Use
* g_io_extension_point_implement() to implement an extension point.
*
* |[<!-- language="C" -->
* GIOExtensionPoint *ep;
*
* // Register an extension point
* ep = g_io_extension_point_register ("my-extension-point");
* g_io_extension_point_set_required_type (ep, MY_TYPE_EXAMPLE);
* ]|
*
* |[<!-- language="C" -->
* // Implement an extension point
* G_DEFINE_TYPE (MyExampleImpl, my_example_impl, MY_TYPE_EXAMPLE)
* g_io_extension_point_implement ("my-extension-point",
* my_example_impl_get_type (),
* "my-example",
* 10);
* ]|
*
* It is up to the code that registered the extension point how
* it uses the implementations that have been associated with it.
* Depending on the use case, it may use all implementations, or
* only the one with the highest priority, or pick a specific
* one by name.
*
* To avoid opening all modules just to find out what extension
* points they implement, GIO makes use of a caching mechanism,
* see [gio-querymodules][gio-querymodules].
* You are expected to run this command after installing a
* GIO module.
*
* The `GIO_EXTRA_MODULES` environment variable can be used to
* specify additional directories to automatically load modules
* from. This environment variable has the same syntax as the
* `PATH`. If two modules have the same base name in different
* directories, then the latter one will be ignored. If additional
* directories are specified GIO will load modules from the built-in
* directory last.
*/
/**
* GIOModuleScope:
*
* Represents a scope for loading IO modules. A scope can be used for blocking
* duplicate modules, or blocking a module you don't want to load.
*
* The scope can be used with g_io_modules_load_all_in_directory_with_scope()
* or g_io_modules_scan_all_in_directory_with_scope().
*
* Since: 2.30
*/
struct _GIOModuleScope {
GIOModuleScopeFlags flags;
GHashTable *basenames;
};
/**
* g_io_module_scope_new:
* @flags: flags for the new scope
*
* Create a new scope for loading of IO modules. A scope can be used for
* blocking duplicate modules, or blocking a module you don't want to load.
*
* Specify the %G_IO_MODULE_SCOPE_BLOCK_DUPLICATES flag to block modules
* which have the same base name as a module that has already been seen
* in this scope.
*
* Returns: (transfer full): the new module scope
*
* Since: 2.30
*/
GIOModuleScope *
g_io_module_scope_new (GIOModuleScopeFlags flags)
{
GIOModuleScope *scope = g_new0 (GIOModuleScope, 1);
scope->flags = flags;
scope->basenames = g_hash_table_new_full (g_str_hash, g_str_equal, g_free, NULL);
return scope;
}
/**
* g_io_module_scope_free:
* @scope: a module loading scope
*
* Free a module scope.
*
* Since: 2.30
*/
void
g_io_module_scope_free (GIOModuleScope *scope)
{
if (!scope)
return;
g_hash_table_destroy (scope->basenames);
g_free (scope);
}
/**
* g_io_module_scope_block:
* @scope: a module loading scope
* @basename: the basename to block
*
* Block modules with the given @basename from being loaded when
* this scope is used with g_io_modules_scan_all_in_directory_with_scope()
* or g_io_modules_load_all_in_directory_with_scope().
*
* Since: 2.30
*/
void
g_io_module_scope_block (GIOModuleScope *scope,
const gchar *basename)
{
gchar *key;
g_return_if_fail (scope != NULL);
g_return_if_fail (basename != NULL);
key = g_strdup (basename);
g_hash_table_add (scope->basenames, key);
}
static gboolean
_g_io_module_scope_contains (GIOModuleScope *scope,
const gchar *basename)
{
return g_hash_table_contains (scope->basenames, basename);
}
struct _GIOModule {
GTypeModule parent_instance;
gchar *filename;
GModule *library;
gboolean initialized; /* The module was loaded at least once */
void (* load) (GIOModule *module);
void (* unload) (GIOModule *module);
};
struct _GIOModuleClass
{
GTypeModuleClass parent_class;
};
static void g_io_module_finalize (GObject *object);
static gboolean g_io_module_load_module (GTypeModule *gmodule);
static void g_io_module_unload_module (GTypeModule *gmodule);
/**
* GIOExtension:
*
* #GIOExtension is an opaque data structure and can only be accessed
* using the following functions.
*/
struct _GIOExtension {
char *name;
GType type;
gint priority;
};
/**
* GIOExtensionPoint:
*
* #GIOExtensionPoint is an opaque data structure and can only be accessed
* using the following functions.
*/
struct _GIOExtensionPoint {
GType required_type;
char *name;
GList *extensions;
GList *lazy_load_modules;
};
static GHashTable *extension_points = NULL;
G_LOCK_DEFINE_STATIC(extension_points);
G_DEFINE_TYPE (GIOModule, g_io_module, G_TYPE_TYPE_MODULE)
static void
g_io_module_class_init (GIOModuleClass *class)
{
GObjectClass *object_class = G_OBJECT_CLASS (class);
GTypeModuleClass *type_module_class = G_TYPE_MODULE_CLASS (class);
object_class->finalize = g_io_module_finalize;
type_module_class->load = g_io_module_load_module;
type_module_class->unload = g_io_module_unload_module;
}
static void
g_io_module_init (GIOModule *module)
{
}
static void
g_io_module_finalize (GObject *object)
{
GIOModule *module = G_IO_MODULE (object);
g_free (module->filename);
G_OBJECT_CLASS (g_io_module_parent_class)->finalize (object);
}
static gboolean
load_symbols (GIOModule *module)
{
gchar *name;
gchar *load_symname;
gchar *unload_symname;
gboolean ret;
name = _g_io_module_extract_name (module->filename);
load_symname = g_strconcat ("g_io_", name, "_load", NULL);
unload_symname = g_strconcat ("g_io_", name, "_unload", NULL);
ret = g_module_symbol (module->library,
load_symname,
(gpointer) &module->load) &&
g_module_symbol (module->library,
unload_symname,
(gpointer) &module->unload);
if (!ret)
{
/* Fallback to old names */
ret = g_module_symbol (module->library,
"g_io_module_load",
(gpointer) &module->load) &&
g_module_symbol (module->library,
"g_io_module_unload",
(gpointer) &module->unload);
}
g_free (name);
g_free (load_symname);
g_free (unload_symname);
return ret;
}
static gboolean
g_io_module_load_module (GTypeModule *gmodule)
{
GIOModule *module = G_IO_MODULE (gmodule);
if (!module->filename)
{
g_warning ("GIOModule path not set");
return FALSE;
}
module->library = g_module_open (module->filename, G_MODULE_BIND_LAZY | G_MODULE_BIND_LOCAL);
if (!module->library)
{
g_printerr ("%s\n", g_module_error ());
return FALSE;
}
/* Make sure that the loaded library contains the required methods */
if (!load_symbols (module))
{
g_printerr ("%s\n", g_module_error ());
g_module_close (module->library);
return FALSE;
}
/* Initialize the loaded module */
module->load (module);
module->initialized = TRUE;
return TRUE;
}
static void
g_io_module_unload_module (GTypeModule *gmodule)
{
GIOModule *module = G_IO_MODULE (gmodule);
module->unload (module);
g_module_close (module->library);
module->library = NULL;
module->load = NULL;
module->unload = NULL;
}
/**
* g_io_module_new:
* @filename: (type filename): filename of the shared library module.
*
* Creates a new GIOModule that will load the specific
* shared library when in use.
*
* Returns: a #GIOModule from given @filename,
* or %NULL on error.
**/
GIOModule *
g_io_module_new (const gchar *filename)
{
GIOModule *module;
g_return_val_if_fail (filename != NULL, NULL);
module = g_object_new (G_IO_TYPE_MODULE, NULL);
module->filename = g_strdup (filename);
return module;
}
static gboolean
is_valid_module_name (const gchar *basename,
GIOModuleScope *scope)
{
gboolean result;
#if !defined(G_OS_WIN32) && !defined(G_WITH_CYGWIN)
if (!g_str_has_prefix (basename, "lib") ||
!g_str_has_suffix (basename, ".so"))
return FALSE;
#else
if (!g_str_has_suffix (basename, ".dll"))
return FALSE;
#endif
result = TRUE;
if (scope)
{
result = _g_io_module_scope_contains (scope, basename) ? FALSE : TRUE;
if (result && (scope->flags & G_IO_MODULE_SCOPE_BLOCK_DUPLICATES))
g_io_module_scope_block (scope, basename);
}
return result;
}
/**
* g_io_modules_scan_all_in_directory_with_scope:
* @dirname: (type filename): pathname for a directory containing modules
* to scan.
* @scope: a scope to use when scanning the modules
*
* Scans all the modules in the specified directory, ensuring that
* any extension point implemented by a module is registered.
*
* This may not actually load and initialize all the types in each
* module, some modules may be lazily loaded and initialized when
* an extension point it implementes is used with e.g.
* g_io_extension_point_get_extensions() or
* g_io_extension_point_get_extension_by_name().
*
* If you need to guarantee that all types are loaded in all the modules,
* use g_io_modules_load_all_in_directory().
*
* Since: 2.30
**/
void
g_io_modules_scan_all_in_directory_with_scope (const char *dirname,
GIOModuleScope *scope)
{
const gchar *name;
char *filename;
GDir *dir;
GStatBuf statbuf;
char *data;
time_t cache_mtime;
GHashTable *cache;
if (!g_module_supported ())
return;
dir = g_dir_open (dirname, 0, NULL);
if (!dir)
return;
filename = g_build_filename (dirname, "giomodule.cache", NULL);
cache = g_hash_table_new_full (g_str_hash, g_str_equal,
g_free, (GDestroyNotify)g_strfreev);
cache_mtime = 0;
if (g_stat (filename, &statbuf) == 0 &&
g_file_get_contents (filename, &data, NULL, NULL))
{
char **lines;
int i;
/* Cache mtime is the time the cache file was created, any file
* that has a ctime before this was created then and not modified
* since then (userspace can't change ctime). Its possible to change
* the ctime forward without changing the file content, by e.g.
* chmoding the file, but this is uncommon and will only cause us
* to not use the cache so will not cause bugs.
*/
cache_mtime = statbuf.st_mtime;
lines = g_strsplit (data, "\n", -1);
g_free (data);
for (i = 0; lines[i] != NULL; i++)
{
char *line = lines[i];
char *file;
char *colon;
char **extension_points;
if (line[0] == '#')
continue;
colon = strchr (line, ':');
if (colon == NULL || line == colon)
continue; /* Invalid line, ignore */
*colon = 0; /* terminate filename */
file = g_strdup (line);
colon++; /* after colon */
while (g_ascii_isspace (*colon))
colon++;
extension_points = g_strsplit (colon, ",", -1);
g_hash_table_insert (cache, file, extension_points);
}
g_strfreev (lines);
}
while ((name = g_dir_read_name (dir)))
{
if (is_valid_module_name (name, scope))
{
GIOExtensionPoint *extension_point;
GIOModule *module;
gchar *path;
char **extension_points;
int i;
path = g_build_filename (dirname, name, NULL);
module = g_io_module_new (path);
extension_points = g_hash_table_lookup (cache, name);
if (extension_points != NULL &&
g_stat (path, &statbuf) == 0 &&
statbuf.st_ctime <= cache_mtime)
{
/* Lazy load/init the library when first required */
for (i = 0; extension_points[i] != NULL; i++)
{
extension_point =
g_io_extension_point_register (extension_points[i]);
extension_point->lazy_load_modules =
g_list_prepend (extension_point->lazy_load_modules,
module);
}
}
else
{
/* Try to load and init types */
if (g_type_module_use (G_TYPE_MODULE (module)))
g_type_module_unuse (G_TYPE_MODULE (module)); /* Unload */
else
{ /* Failure to load */
g_printerr ("Failed to load module: %s\n", path);
g_object_unref (module);
g_free (path);
continue;
}
}
g_free (path);
}
}
g_dir_close (dir);
g_hash_table_destroy (cache);
g_free (filename);
}
/**
* g_io_modules_scan_all_in_directory:
* @dirname: (type filename): pathname for a directory containing modules
* to scan.
*
* Scans all the modules in the specified directory, ensuring that
* any extension point implemented by a module is registered.
*
* This may not actually load and initialize all the types in each
* module, some modules may be lazily loaded and initialized when
* an extension point it implementes is used with e.g.
* g_io_extension_point_get_extensions() or
* g_io_extension_point_get_extension_by_name().
*
* If you need to guarantee that all types are loaded in all the modules,
* use g_io_modules_load_all_in_directory().
*
* Since: 2.24
**/
void
g_io_modules_scan_all_in_directory (const char *dirname)
{
g_io_modules_scan_all_in_directory_with_scope (dirname, NULL);
}
/**
* g_io_modules_load_all_in_directory_with_scope:
* @dirname: (type filename): pathname for a directory containing modules
* to load.
* @scope: a scope to use when scanning the modules.
*
* Loads all the modules in the specified directory.
*
* If don't require all modules to be initialized (and thus registering
* all gtypes) then you can use g_io_modules_scan_all_in_directory()
* which allows delayed/lazy loading of modules.
*
* Returns: (element-type GIOModule) (transfer full): a list of #GIOModules loaded
* from the directory,
* All the modules are loaded into memory, if you want to
* unload them (enabling on-demand loading) you must call
* g_type_module_unuse() on all the modules. Free the list
* with g_list_free().
*
* Since: 2.30
**/
GList *
g_io_modules_load_all_in_directory_with_scope (const char *dirname,
GIOModuleScope *scope)
{
const gchar *name;
GDir *dir;
GList *modules;
if (!g_module_supported ())
return NULL;
dir = g_dir_open (dirname, 0, NULL);
if (!dir)
return NULL;
modules = NULL;
while ((name = g_dir_read_name (dir)))
{
if (is_valid_module_name (name, scope))
{
GIOModule *module;
gchar *path;
path = g_build_filename (dirname, name, NULL);
module = g_io_module_new (path);
if (!g_type_module_use (G_TYPE_MODULE (module)))
{
g_printerr ("Failed to load module: %s\n", path);
g_object_unref (module);
g_free (path);
continue;
}
g_free (path);
modules = g_list_prepend (modules, module);
}
}
g_dir_close (dir);
return modules;
}
/**
* g_io_modules_load_all_in_directory:
* @dirname: (type filename): pathname for a directory containing modules
* to load.
*
* Loads all the modules in the specified directory.
*
* If don't require all modules to be initialized (and thus registering
* all gtypes) then you can use g_io_modules_scan_all_in_directory()
* which allows delayed/lazy loading of modules.
*
* Returns: (element-type GIOModule) (transfer full): a list of #GIOModules loaded
* from the directory,
* All the modules are loaded into memory, if you want to
* unload them (enabling on-demand loading) you must call
* g_type_module_unuse() on all the modules. Free the list
* with g_list_free().
**/
GList *
g_io_modules_load_all_in_directory (const char *dirname)
{
return g_io_modules_load_all_in_directory_with_scope (dirname, NULL);
}
static gpointer
try_class (GIOExtension *extension,
guint is_supported_offset)
{
GType type = g_io_extension_get_type (extension);
typedef gboolean (*verify_func) (void);
gpointer class;
class = g_type_class_ref (type);
if (!is_supported_offset || (* G_STRUCT_MEMBER(verify_func, class, is_supported_offset)) ())
return class;
g_type_class_unref (class);
return NULL;
}
static void
print_help (const char *envvar,
GIOExtensionPoint *ep)
{
g_print ("Supported arguments for %s environment variable:\n", envvar);
if (g_io_extension_point_get_extensions (ep) == NULL)
g_print (" (none)\n");
else
{
GList *l;
GIOExtension *extension;
int width = 0;
for (l = g_io_extension_point_get_extensions (ep); l; l = l->next)
{
extension = l->data;
width = MAX (width, strlen (g_io_extension_get_name (extension)));
}
for (l = g_io_extension_point_get_extensions (ep); l; l = l->next)
{
extension = l->data;
g_print (" %*s - %d\n", width, g_io_extension_get_name (extension), g_io_extension_get_priority (extension));
}
}
}
/**
* _g_io_module_get_default_type:
* @extension_point: the name of an extension point
* @envvar: (nullable): the name of an environment variable to
* override the default implementation.
* @is_supported_offset: a vtable offset, or zero
*
* Retrieves the default class implementing @extension_point.
*
* If @envvar is not %NULL, and the environment variable with that
* name is set, then the implementation it specifies will be tried
* first. After that, or if @envvar is not set, all other
* implementations will be tried in order of decreasing priority.
*
* If @is_supported_offset is non-zero, then it is the offset into the
* class vtable at which there is a function that takes no arguments and
* returns a boolean. This function will be called on each candidate
* implementation to check if it is actually usable or not.
*
* The result is cached after it is generated the first time, and
* the function is thread-safe.
*
* Returns: (transfer none): the type to instantiate to implement
* @extension_point, or %G_TYPE_INVALID if there are no usable
* implementations.
*/
GType
_g_io_module_get_default_type (const gchar *extension_point,
const gchar *envvar,
guint is_supported_offset)
{
static GRecMutex default_modules_lock;
static GHashTable *default_modules;
const char *use_this;
GList *l;
GIOExtensionPoint *ep;
GIOExtension *extension, *preferred;
gpointer impl;
g_rec_mutex_lock (&default_modules_lock);
if (default_modules)
{
gpointer key;
if (g_hash_table_lookup_extended (default_modules, extension_point, &key, &impl))
{
g_rec_mutex_unlock (&default_modules_lock);
return impl ? G_OBJECT_CLASS_TYPE (impl) : G_TYPE_INVALID;
}
}
else
{
default_modules = g_hash_table_new (g_str_hash, g_str_equal);
}
_g_io_modules_ensure_loaded ();
ep = g_io_extension_point_lookup (extension_point);
if (!ep)
{
g_warn_if_reached ();
g_rec_mutex_unlock (&default_modules_lock);
return G_TYPE_INVALID;
}
use_this = envvar ? g_getenv (envvar) : NULL;
if (g_strcmp0 (use_this, "help") == 0)
{
print_help (envvar, ep);
use_this = NULL;
}
if (use_this)
{
preferred = g_io_extension_point_get_extension_by_name (ep, use_this);
if (preferred)
{
impl = try_class (preferred, is_supported_offset);
if (impl)
goto done;
}
else
g_warning ("Can't find module '%s' specified in %s", use_this, envvar);
}
else
preferred = NULL;
for (l = g_io_extension_point_get_extensions (ep); l != NULL; l = l->next)
{
extension = l->data;
if (extension == preferred)
continue;
impl = try_class (extension, is_supported_offset);
if (impl)
goto done;
}
impl = NULL;
done:
g_hash_table_insert (default_modules, g_strdup (extension_point), impl);
g_rec_mutex_unlock (&default_modules_lock);
return impl ? G_OBJECT_CLASS_TYPE (impl) : G_TYPE_INVALID;
}
static gpointer
try_implementation (const char *extension_point,
GIOExtension *extension,
GIOModuleVerifyFunc verify_func)
{
GType type = g_io_extension_get_type (extension);
gpointer impl;
if (g_type_is_a (type, G_TYPE_INITABLE))
{
GError *error = NULL;
impl = g_initable_new (type, NULL, &error, NULL);
if (impl)
return impl;
g_debug ("Failed to initialize %s (%s) for %s: %s",
g_io_extension_get_name (extension),
g_type_name (type),
extension_point,
error ? error->message : "");
g_clear_error (&error);
return NULL;
}
else
{
impl = g_object_new (type, NULL);
if (!verify_func || verify_func (impl))
return impl;
g_object_unref (impl);
return NULL;
}
}
/**
* _g_io_module_get_default:
* @extension_point: the name of an extension point
* @envvar: (nullable): the name of an environment variable to
* override the default implementation.
* @verify_func: (nullable): a function to call to verify that
* a given implementation is usable in the current environment.
*
* Retrieves the default object implementing @extension_point.
*
* If @envvar is not %NULL, and the environment variable with that
* name is set, then the implementation it specifies will be tried
* first. After that, or if @envvar is not set, all other
* implementations will be tried in order of decreasing priority.
*
* If an extension point implementation implements #GInitable, then
* that implementation will only be used if it initializes
* successfully. Otherwise, if @verify_func is not %NULL, then it will
* be called on each candidate implementation after construction, to
* check if it is actually usable or not.
*
* The result is cached after it is generated the first time, and
* the function is thread-safe.
*
* Returns: (transfer none): an object implementing
* @extension_point, or %NULL if there are no usable
* implementations.
*/
gpointer
_g_io_module_get_default (const gchar *extension_point,
const gchar *envvar,
GIOModuleVerifyFunc verify_func)
{
static GRecMutex default_modules_lock;
static GHashTable *default_modules;
const char *use_this;
GList *l;
GIOExtensionPoint *ep;
GIOExtension *extension = NULL, *preferred;
gpointer impl;
g_rec_mutex_lock (&default_modules_lock);
if (default_modules)
{
gpointer key;
if (g_hash_table_lookup_extended (default_modules, extension_point,
&key, &impl))
{
/* Dont debug here, since were returning a cached object which was
* already printed earlier. */
g_rec_mutex_unlock (&default_modules_lock);
return impl;
}
}
else
{
default_modules = g_hash_table_new (g_str_hash, g_str_equal);
}
_g_io_modules_ensure_loaded ();
ep = g_io_extension_point_lookup (extension_point);
if (!ep)
{
g_debug ("%s: Failed to find extension point %s",
G_STRFUNC, extension_point);
g_warn_if_reached ();
g_rec_mutex_unlock (&default_modules_lock);
return NULL;
}
use_this = envvar ? g_getenv (envvar) : NULL;
if (g_strcmp0 (use_this, "help") == 0)
{
print_help (envvar, ep);
use_this = NULL;
}
if (use_this)
{
preferred = g_io_extension_point_get_extension_by_name (ep, use_this);
if (preferred)
{
impl = try_implementation (extension_point, preferred, verify_func);
extension = preferred;
if (impl)
goto done;
}
else
g_warning ("Can't find module '%s' specified in %s", use_this, envvar);
}
else
preferred = NULL;
for (l = g_io_extension_point_get_extensions (ep); l != NULL; l = l->next)
{
extension = l->data;
if (extension == preferred)
continue;
impl = try_implementation (extension_point, extension, verify_func);
if (impl)
goto done;
}
impl = NULL;
done:
g_hash_table_insert (default_modules,
g_strdup (extension_point),
impl ? g_object_ref (impl) : NULL);
g_rec_mutex_unlock (&default_modules_lock);
if (impl != NULL)
{
g_assert (extension != NULL);
g_debug ("%s: Found default implementation %s (%s) for %s",
G_STRFUNC, g_io_extension_get_name (extension),
G_OBJECT_TYPE_NAME (impl), extension_point);
}
else
g_debug ("%s: Failed to find default implementation for %s",
G_STRFUNC, extension_point);
return impl;
}
G_LOCK_DEFINE_STATIC (registered_extensions);
G_LOCK_DEFINE_STATIC (loaded_dirs);
extern GType g_fen_file_monitor_get_type (void);
extern GType g_inotify_file_monitor_get_type (void);
extern GType g_kqueue_file_monitor_get_type (void);
extern GType g_win32_file_monitor_get_type (void);
extern GType _g_unix_volume_monitor_get_type (void);
extern GType _g_local_vfs_get_type (void);
extern GType _g_win32_volume_monitor_get_type (void);
extern GType _g_winhttp_vfs_get_type (void);
extern GType _g_dummy_proxy_resolver_get_type (void);
extern GType _g_dummy_tls_backend_get_type (void);
extern GType g_network_monitor_base_get_type (void);
#ifdef HAVE_NETLINK
extern GType _g_network_monitor_netlink_get_type (void);
extern GType _g_network_monitor_nm_get_type (void);
#endif
#ifdef G_OS_UNIX
extern GType g_fdo_notification_backend_get_type (void);
extern GType g_gtk_notification_backend_get_type (void);
extern GType g_portal_notification_backend_get_type (void);
extern GType g_proxy_resolver_portal_get_type (void);
extern GType g_network_monitor_portal_get_type (void);
#endif
#if MAC_OS_X_VERSION_MIN_REQUIRED >= 1090
extern GType g_cocoa_notification_backend_get_type (void);
#endif
#ifdef G_PLATFORM_WIN32
extern GType g_win32_notification_backend_get_type (void);
#include <windows.h>
extern GType _g_win32_network_monitor_get_type (void);
static HMODULE gio_dll = NULL;
#ifdef DLL_EXPORT
BOOL WINAPI DllMain (HINSTANCE hinstDLL,
DWORD fdwReason,
LPVOID lpvReserved);
BOOL WINAPI
DllMain (HINSTANCE hinstDLL,
DWORD fdwReason,
LPVOID lpvReserved)
{
if (fdwReason == DLL_PROCESS_ATTACH)
gio_dll = hinstDLL;
return TRUE;
}
#endif
void *
_g_io_win32_get_module (void)
{
if (!gio_dll)
GetModuleHandleExA (GET_MODULE_HANDLE_EX_FLAG_FROM_ADDRESS,
(const char *) _g_io_win32_get_module,
&gio_dll);
return gio_dll;
}
#endif
void
_g_io_modules_ensure_extension_points_registered (void)
{
static gboolean registered_extensions = FALSE;
GIOExtensionPoint *ep;
G_LOCK (registered_extensions);
if (!registered_extensions)
{
registered_extensions = TRUE;
#if defined(G_OS_UNIX) && !defined(HAVE_COCOA)
#if !GLIB_CHECK_VERSION (3, 0, 0)
ep = g_io_extension_point_register (G_DESKTOP_APP_INFO_LOOKUP_EXTENSION_POINT_NAME);
G_GNUC_BEGIN_IGNORE_DEPRECATIONS
g_io_extension_point_set_required_type (ep, G_TYPE_DESKTOP_APP_INFO_LOOKUP);
G_GNUC_END_IGNORE_DEPRECATIONS
#endif
#endif
ep = g_io_extension_point_register (G_LOCAL_FILE_MONITOR_EXTENSION_POINT_NAME);
g_io_extension_point_set_required_type (ep, G_TYPE_LOCAL_FILE_MONITOR);
ep = g_io_extension_point_register (G_NFS_FILE_MONITOR_EXTENSION_POINT_NAME);
g_io_extension_point_set_required_type (ep, G_TYPE_LOCAL_FILE_MONITOR);
ep = g_io_extension_point_register (G_VOLUME_MONITOR_EXTENSION_POINT_NAME);
g_io_extension_point_set_required_type (ep, G_TYPE_VOLUME_MONITOR);
ep = g_io_extension_point_register (G_NATIVE_VOLUME_MONITOR_EXTENSION_POINT_NAME);
g_io_extension_point_set_required_type (ep, G_TYPE_NATIVE_VOLUME_MONITOR);
ep = g_io_extension_point_register (G_VFS_EXTENSION_POINT_NAME);
g_io_extension_point_set_required_type (ep, G_TYPE_VFS);
ep = g_io_extension_point_register ("gsettings-backend");
g_io_extension_point_set_required_type (ep, G_TYPE_OBJECT);
ep = g_io_extension_point_register (G_PROXY_RESOLVER_EXTENSION_POINT_NAME);
g_io_extension_point_set_required_type (ep, G_TYPE_PROXY_RESOLVER);
ep = g_io_extension_point_register (G_PROXY_EXTENSION_POINT_NAME);
g_io_extension_point_set_required_type (ep, G_TYPE_PROXY);
ep = g_io_extension_point_register (G_TLS_BACKEND_EXTENSION_POINT_NAME);
g_io_extension_point_set_required_type (ep, G_TYPE_TLS_BACKEND);
ep = g_io_extension_point_register (G_NETWORK_MONITOR_EXTENSION_POINT_NAME);
g_io_extension_point_set_required_type (ep, G_TYPE_NETWORK_MONITOR);
ep = g_io_extension_point_register (G_NOTIFICATION_BACKEND_EXTENSION_POINT_NAME);
g_io_extension_point_set_required_type (ep, G_TYPE_NOTIFICATION_BACKEND);
}
G_UNLOCK (registered_extensions);
}
static gchar *
get_gio_module_dir (void)
{
gchar *module_dir;
module_dir = g_strdup (g_getenv ("GIO_MODULE_DIR"));
if (module_dir == NULL)
{
#ifdef G_OS_WIN32
gchar *install_dir;
install_dir = g_win32_get_package_installation_directory_of_module (gio_dll);
#ifdef _MSC_VER
/* On Visual Studio builds we have all the libraries and binaries in bin
* so better load the gio modules from bin instead of lib
*/
module_dir = g_build_filename (install_dir,
"bin", "gio", "modules",
NULL);
#else
module_dir = g_build_filename (install_dir,
"lib", "gio", "modules",
NULL);
#endif
g_free (install_dir);
#else
module_dir = g_strdup (GIO_MODULE_DIR);
#endif
}
return module_dir;
}
void
_g_io_modules_ensure_loaded (void)
{
static gboolean loaded_dirs = FALSE;
const char *module_path;
GIOModuleScope *scope;
_g_io_modules_ensure_extension_points_registered ();
G_LOCK (loaded_dirs);
if (!loaded_dirs)
{
gchar *module_dir;
loaded_dirs = TRUE;
scope = g_io_module_scope_new (G_IO_MODULE_SCOPE_BLOCK_DUPLICATES);
/* First load any overrides, extras */
module_path = g_getenv ("GIO_EXTRA_MODULES");
if (module_path)
{
gchar **paths;
int i;
paths = g_strsplit (module_path, G_SEARCHPATH_SEPARATOR_S, 0);
for (i = 0; paths[i] != NULL; i++)
{
g_io_modules_scan_all_in_directory_with_scope (paths[i], scope);
}
g_strfreev (paths);
}
/* Then load the compiled in path */
module_dir = get_gio_module_dir ();
g_io_modules_scan_all_in_directory_with_scope (module_dir, scope);
g_free (module_dir);
g_io_module_scope_free (scope);
/* Initialize types from built-in "modules" */
g_type_ensure (g_null_settings_backend_get_type ());
g_type_ensure (g_memory_settings_backend_get_type ());
#if defined(HAVE_INOTIFY_INIT1)
g_type_ensure (g_inotify_file_monitor_get_type ());
#endif
#if defined(HAVE_KQUEUE)
g_type_ensure (g_kqueue_file_monitor_get_type ());
#endif
#if defined(HAVE_FEN)
g_type_ensure (g_fen_file_monitor_get_type ());
#endif
#ifdef G_OS_WIN32
g_type_ensure (_g_win32_volume_monitor_get_type ());
g_type_ensure (g_win32_file_monitor_get_type ());
g_type_ensure (g_registry_backend_get_type ());
#endif
#ifdef HAVE_COCOA
g_type_ensure (g_nextstep_settings_backend_get_type ());
g_type_ensure (g_osx_app_info_get_type ());
#endif
#ifdef G_OS_UNIX
g_type_ensure (_g_unix_volume_monitor_get_type ());
g_type_ensure (g_fdo_notification_backend_get_type ());
g_type_ensure (g_gtk_notification_backend_get_type ());
g_type_ensure (g_portal_notification_backend_get_type ());
g_type_ensure (g_network_monitor_portal_get_type ());
g_type_ensure (g_proxy_resolver_portal_get_type ());
#endif
#if HAVE_MAC_OS_X_VERSION_MIN_REQUIRED >= 1090
g_type_ensure (g_cocoa_notification_backend_get_type ());
#endif
#ifdef G_OS_WIN32
g_type_ensure (g_win32_notification_backend_get_type ());
g_type_ensure (_g_winhttp_vfs_get_type ());
#endif
g_type_ensure (_g_local_vfs_get_type ());
g_type_ensure (_g_dummy_proxy_resolver_get_type ());
g_type_ensure (_g_http_proxy_get_type ());
g_type_ensure (_g_https_proxy_get_type ());
g_type_ensure (_g_socks4a_proxy_get_type ());
g_type_ensure (_g_socks4_proxy_get_type ());
g_type_ensure (_g_socks5_proxy_get_type ());
g_type_ensure (_g_dummy_tls_backend_get_type ());
g_type_ensure (g_network_monitor_base_get_type ());
#ifdef HAVE_NETLINK
g_type_ensure (_g_network_monitor_netlink_get_type ());
g_type_ensure (_g_network_monitor_nm_get_type ());
#endif
#ifdef G_OS_WIN32
g_type_ensure (_g_win32_network_monitor_get_type ());
#endif
}
G_UNLOCK (loaded_dirs);
}
static void
g_io_extension_point_free (GIOExtensionPoint *ep)
{
g_free (ep->name);
g_free (ep);
}
/**
* g_io_extension_point_register:
* @name: The name of the extension point
*
* Registers an extension point.
*
* Returns: (transfer none): the new #GIOExtensionPoint. This object is
* owned by GIO and should not be freed.
*/
GIOExtensionPoint *
g_io_extension_point_register (const char *name)
{
GIOExtensionPoint *ep;
G_LOCK (extension_points);
if (extension_points == NULL)
extension_points = g_hash_table_new_full (g_str_hash,
g_str_equal,
NULL,
(GDestroyNotify)g_io_extension_point_free);
ep = g_hash_table_lookup (extension_points, name);
if (ep != NULL)
{
G_UNLOCK (extension_points);
return ep;
}
ep = g_new0 (GIOExtensionPoint, 1);
ep->name = g_strdup (name);
g_hash_table_insert (extension_points, ep->name, ep);
G_UNLOCK (extension_points);
return ep;
}
/**
* g_io_extension_point_lookup:
* @name: the name of the extension point
*
* Looks up an existing extension point.
*
* Returns: (transfer none): the #GIOExtensionPoint, or %NULL if there
* is no registered extension point with the given name.
*/
GIOExtensionPoint *
g_io_extension_point_lookup (const char *name)
{
GIOExtensionPoint *ep;
G_LOCK (extension_points);
ep = NULL;
if (extension_points != NULL)
ep = g_hash_table_lookup (extension_points, name);
G_UNLOCK (extension_points);
return ep;
}
/**
* g_io_extension_point_set_required_type:
* @extension_point: a #GIOExtensionPoint
* @type: the #GType to require
*
* Sets the required type for @extension_point to @type.
* All implementations must henceforth have this type.
*/
void
g_io_extension_point_set_required_type (GIOExtensionPoint *extension_point,
GType type)
{
extension_point->required_type = type;
}
/**
* g_io_extension_point_get_required_type:
* @extension_point: a #GIOExtensionPoint
*
* Gets the required type for @extension_point.
*
* Returns: the #GType that all implementations must have,
* or #G_TYPE_INVALID if the extension point has no required type
*/
GType
g_io_extension_point_get_required_type (GIOExtensionPoint *extension_point)
{
return extension_point->required_type;
}
static void
lazy_load_modules (GIOExtensionPoint *extension_point)
{
GIOModule *module;
GList *l;
for (l = extension_point->lazy_load_modules; l != NULL; l = l->next)
{
module = l->data;
if (!module->initialized)
{
if (g_type_module_use (G_TYPE_MODULE (module)))
g_type_module_unuse (G_TYPE_MODULE (module)); /* Unload */
else
g_printerr ("Failed to load module: %s\n",
module->filename);
}
}
}
/**
* g_io_extension_point_get_extensions:
* @extension_point: a #GIOExtensionPoint
*
* Gets a list of all extensions that implement this extension point.
* The list is sorted by priority, beginning with the highest priority.
*
* Returns: (element-type GIOExtension) (transfer none): a #GList of
* #GIOExtensions. The list is owned by GIO and should not be
* modified.
*/
GList *
g_io_extension_point_get_extensions (GIOExtensionPoint *extension_point)
{
g_return_val_if_fail (extension_point != NULL, NULL);
lazy_load_modules (extension_point);
return extension_point->extensions;
}
/**
* g_io_extension_point_get_extension_by_name:
* @extension_point: a #GIOExtensionPoint
* @name: the name of the extension to get
*
* Finds a #GIOExtension for an extension point by name.
*
* Returns: (transfer none): the #GIOExtension for @extension_point that has the
* given name, or %NULL if there is no extension with that name
*/
GIOExtension *
g_io_extension_point_get_extension_by_name (GIOExtensionPoint *extension_point,
const char *name)
{
GList *l;
g_return_val_if_fail (name != NULL, NULL);
lazy_load_modules (extension_point);
for (l = extension_point->extensions; l != NULL; l = l->next)
{
GIOExtension *e = l->data;
if (e->name != NULL &&
strcmp (e->name, name) == 0)
return e;
}
return NULL;
}
static gint
extension_prio_compare (gconstpointer a,
gconstpointer b)
{
const GIOExtension *extension_a = a, *extension_b = b;
if (extension_a->priority > extension_b->priority)
return -1;
if (extension_b->priority > extension_a->priority)
return 1;
return 0;
}
/**
* g_io_extension_point_implement:
* @extension_point_name: the name of the extension point
* @type: the #GType to register as extension
* @extension_name: the name for the extension
* @priority: the priority for the extension
*
* Registers @type as extension for the extension point with name
* @extension_point_name.
*
* If @type has already been registered as an extension for this
* extension point, the existing #GIOExtension object is returned.
*
* Returns: (transfer none): a #GIOExtension object for #GType
*/
GIOExtension *
g_io_extension_point_implement (const char *extension_point_name,
GType type,
const char *extension_name,
gint priority)
{
GIOExtensionPoint *extension_point;
GIOExtension *extension;
GList *l;
g_return_val_if_fail (extension_point_name != NULL, NULL);
extension_point = g_io_extension_point_lookup (extension_point_name);
if (extension_point == NULL)
{
g_warning ("Tried to implement non-registered extension point %s", extension_point_name);
return NULL;
}
if (extension_point->required_type != 0 &&
!g_type_is_a (type, extension_point->required_type))
{
g_warning ("Tried to register an extension of the type %s to extension point %s. "
"Expected type is %s.",
g_type_name (type),
extension_point_name,
g_type_name (extension_point->required_type));
return NULL;
}
/* It's safe to register the same type multiple times */
for (l = extension_point->extensions; l != NULL; l = l->next)
{
extension = l->data;
if (extension->type == type)
return extension;
}
extension = g_slice_new0 (GIOExtension);
extension->type = type;
extension->name = g_strdup (extension_name);
extension->priority = priority;
extension_point->extensions = g_list_insert_sorted (extension_point->extensions,
extension, extension_prio_compare);
return extension;
}
/**
* g_io_extension_ref_class:
* @extension: a #GIOExtension
*
* Gets a reference to the class for the type that is
* associated with @extension.
*
* Returns: (transfer full): the #GTypeClass for the type of @extension
*/
GTypeClass *
g_io_extension_ref_class (GIOExtension *extension)
{
return g_type_class_ref (extension->type);
}
/**
* g_io_extension_get_type:
* @extension: a #GIOExtension
*
* Gets the type associated with @extension.
*
* Returns: the type of @extension
*/
GType
g_io_extension_get_type (GIOExtension *extension)
{
return extension->type;
}
/**
* g_io_extension_get_name:
* @extension: a #GIOExtension
*
* Gets the name under which @extension was registered.
*
* Note that the same type may be registered as extension
* for multiple extension points, under different names.
*
* Returns: the name of @extension.
*/
const char *
g_io_extension_get_name (GIOExtension *extension)
{
return extension->name;
}
/**
* g_io_extension_get_priority:
* @extension: a #GIOExtension
*
* Gets the priority with which @extension was registered.
*
* Returns: the priority of @extension
*/
gint
g_io_extension_get_priority (GIOExtension *extension)
{
return extension->priority;
}