2 * Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
3 * 2000 Wim Taymans <wtay@chello.be>
5 * gstplugin.c: Plugin subsystem for loading elements, types, and libs
7 * This library is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Library General Public
9 * License as published by the Free Software Foundation; either
10 * version 2 of the License, or (at your option) any later version.
12 * This library is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Library General Public License for more details.
17 * You should have received a copy of the GNU Library General Public
18 * License along with this library; if not, write to the
19 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
20 * Boston, MA 02111-1307, USA.
26 #include <sys/types.h>
37 #include "gst_private.h"
39 #include "gstplugin.h"
40 #include "gstversion.h"
41 #include "gstregistrypool.h"
43 #include "gstfilter.h"
46 #define GST_CAT_DEFAULT GST_CAT_PLUGIN_LOADING
48 static GModule *main_module = NULL;
49 static GList *_gst_plugin_static = NULL;
51 /* static variables for segfault handling of plugin loading */
52 static char *_gst_plugin_fault_handler_filename = NULL;
53 extern gboolean *_gst_disable_segtrap; /* see gst.c */
56 static gboolean *_gst_plugin_fault_handler_is_setup = FALSE;
59 /* list of valid licenses.
60 * One of these must be specified or the plugin won't be loaded
61 * Contact gstreamer-devel@lists.sourceforge.net if your license should be
64 * GPL: http://www.gnu.org/copyleft/gpl.html
65 * LGPL: http://www.gnu.org/copyleft/lesser.html
66 * QPL: http://www.trolltech.com/licenses/qpl.html
68 static gchar *valid_licenses[] = {
69 "LGPL", /* GNU Lesser General Public License */
70 "GPL", /* GNU General Public License */
71 "QPL", /* Trolltech Qt Public License */
72 "GPL/QPL", /* Combi-license of GPL + QPL */
73 GST_LICENSE_UNKNOWN, /* some other license */
77 static void gst_plugin_desc_copy (GstPluginDesc * dest,
78 const GstPluginDesc * src);
80 static GstPlugin *gst_plugin_register_func (GstPlugin * plugin,
81 GModule * module, GstPluginDesc * desc);
84 gst_plugin_copy (GstPlugin * plugin)
86 return g_memdup (plugin, sizeof (*plugin));
90 gst_plugin_get_type (void)
92 static GType plugin_type;
94 if (plugin_type == 0) {
95 plugin_type = g_boxed_type_register_static ("GstPlugin",
96 (GBoxedCopyFunc) gst_plugin_copy, g_free);
103 gst_plugin_error_quark (void)
105 static GQuark quark = 0;
108 quark = g_quark_from_static_string ("gst_plugin_error");
112 /* this function can be called in the GCC constructor extension, before
113 * the _gst_plugin_initialize() was called. In that case, we store the
114 * plugin description in a list to initialize it when we open the main
116 * When the main module is known, we can register the plugin right away.
119 _gst_plugin_register_static (GstPluginDesc * desc)
121 if (main_module == NULL) {
123 GST_LOG ("queueing static plugin \"%s\" for loading later on",
125 _gst_plugin_static = g_list_prepend (_gst_plugin_static, desc);
130 GST_LOG ("attempting to load static plugin \"%s\" now...", desc->name);
131 plugin = g_new0 (GstPlugin, 1);
132 if (gst_plugin_register_func (plugin, main_module, desc)) {
134 GST_INFO ("loaded static plugin \"%s\"", desc->name);
135 gst_registry_pool_add_plugin (plugin);
141 _gst_plugin_initialize (void)
143 main_module = g_module_open (NULL, G_MODULE_BIND_LAZY);
145 /* now register all static plugins */
146 g_list_foreach (_gst_plugin_static, (GFunc) _gst_plugin_register_static,
150 /* this function could be extended to check if the plugin license matches the
151 * applications license (would require the app to register its license somehow).
152 * We'll wait for someone who's interested in it to code it :)
155 gst_plugin_check_license (const gchar * license)
157 gchar **check_license = valid_licenses;
159 g_assert (check_license);
161 while (*check_license) {
162 if (strcmp (license, *check_license) == 0)
170 gst_plugin_check_version (gint major, gint minor)
172 /* return NULL if the major and minor version numbers are not compatible */
174 if (major != GST_VERSION_MAJOR || minor != GST_VERSION_MINOR)
181 gst_plugin_register_func (GstPlugin * plugin, GModule * module,
182 GstPluginDesc * desc)
184 g_assert (plugin->module == NULL);
186 if (!gst_plugin_check_version (desc->major_version, desc->minor_version)) {
188 GST_INFO ("plugin \"%s\" has incompatible version, not loading",
193 if (!desc->license || !desc->description || !desc->package || !desc->origin) {
195 GST_INFO ("plugin \"%s\" has incorrect GstPluginDesc, not loading",
200 if (!gst_plugin_check_license (desc->license)) {
202 GST_INFO ("plugin \"%s\" has invalid license \"%s\", not loading",
203 plugin->filename, desc->license);
207 gst_plugin_desc_copy (&plugin->desc, desc);
208 plugin->module = module;
210 if (!((desc->plugin_init) (plugin))) {
212 GST_INFO ("plugin \"%s\" failed to initialise", plugin->filename);
213 plugin->module = NULL;
218 GST_LOG ("plugin \"%s\" initialised", GST_STR_NULL (plugin->filename));
225 * _gst_plugin_fault_handler_restore:
226 * segfault handler restorer
229 _gst_plugin_fault_handler_restore (void)
231 struct sigaction action;
233 memset (&action, 0, sizeof (action));
234 action.sa_handler = SIG_DFL;
236 sigaction (SIGSEGV, &action, NULL);
240 * _gst_plugin_fault_handler_sighandler:
241 * segfault handler implementation
244 _gst_plugin_fault_handler_sighandler (int signum)
246 /* We need to restore the fault handler or we'll keep getting it */
247 _gst_plugin_fault_handler_restore ();
251 g_print ("\nERROR: ");
252 g_print ("Caught a segmentation fault while loading plugin file:\n");
253 g_print ("%s\n\n", _gst_plugin_fault_handler_filename);
254 g_print ("Please either:\n");
255 g_print ("- remove it and restart.\n");
256 g_print ("- run with --gst-disable-segtrap and debug.\n");
260 g_print ("Caught unhandled signal on plugin loading\n");
266 * _gst_plugin_fault_handler_setup:
267 * sets up the segfault handler
270 _gst_plugin_fault_handler_setup (void)
272 struct sigaction action;
274 /* if asked to leave segfaults alone, just return */
275 if (_gst_disable_segtrap)
278 if (_gst_plugin_fault_handler_is_setup)
281 memset (&action, 0, sizeof (action));
282 action.sa_handler = _gst_plugin_fault_handler_sighandler;
284 sigaction (SIGSEGV, &action, NULL);
288 _gst_plugin_fault_handler_restore (void)
293 _gst_plugin_fault_handler_setup (void)
298 static void _gst_plugin_fault_handler_setup ();
301 * gst_plugin_check_file:
302 * @filename: the plugin filename to check for pluginness
303 * @error: pointer to a NULL-valued GError
305 * Checks if the given path represents a GStreamer plugin.
307 * Returns: TRUE if the given path is a GStreamer plugin.
310 gst_plugin_check_file (const gchar * filename, GError ** error)
313 struct stat file_status;
316 g_return_val_if_fail (filename != NULL, FALSE);
318 if (g_module_supported () == FALSE) {
321 GST_PLUGIN_ERROR_MODULE, "Dynamic loading not supported");
325 if (stat (filename, &file_status)) {
328 GST_PLUGIN_ERROR_MODULE, "Problem accessing file %s: %s\n", filename,
333 module = g_module_open (filename, G_MODULE_BIND_LAZY);
335 if (module == NULL) {
336 GST_DEBUG ("Error loading plugin %s, reason: %s\n", filename,
338 g_set_error (error, GST_PLUGIN_ERROR, GST_PLUGIN_ERROR_MODULE,
339 "Error loading plugin %s, reason: %s\n", filename, g_module_error ());
343 if (!g_module_symbol (module, "gst_plugin_desc", &ptr)) {
344 GST_DEBUG ("Could not find plugin entry point in \"%s\"", filename);
347 GST_PLUGIN_ERROR_MODULE,
348 "Could not find plugin entry point in \"%s\"", filename);
349 g_module_close (module);
353 GST_INFO ("looks like a gst plugin \"%s\"", filename);
354 g_module_close (module);
359 * gst_plugin_load_file:
360 * @filename: the plugin filename to load
361 * @error: pointer to a NULL-valued GError
363 * Loads the given plugin.
365 * Returns: a new GstPlugin or NULL, if an error occurred.
368 gst_plugin_load_file (const gchar * filename, GError ** error)
373 gboolean free_plugin;
376 g_return_val_if_fail (filename != NULL, NULL);
378 GST_CAT_DEBUG (GST_CAT_PLUGIN_LOADING, "attempt to load plugin \"%s\"",
381 if (!gst_plugin_check_file (filename, error))
384 module = g_module_open (filename, G_MODULE_BIND_LAZY);
389 if (!g_module_symbol (module, "gst_plugin_desc", &ptr))
392 desc = (GstPluginDesc *) ptr;
394 plugin = gst_registry_pool_find_plugin (desc->name);
397 plugin = g_new0 (GstPlugin, 1);
398 plugin->filename = g_strdup (filename);
399 GST_DEBUG ("created new GstPlugin %p for file \"%s\"", plugin, filename);
402 if (gst_plugin_is_loaded (plugin)) {
403 if (plugin->filename && strcmp (plugin->filename, filename) != 0) {
405 ("plugin %p from file \"%s\" with same name %s is already "
406 "loaded, aborting loading of \"%s\"", plugin, plugin->filename,
407 plugin->desc.name, filename);
408 g_set_error (error, GST_PLUGIN_ERROR,
409 GST_PLUGIN_ERROR_NAME_MISMATCH,
410 "plugin %p from file \"%s\" with same name %s is already "
411 "loaded, aborting loading of \"%s\"", plugin, plugin->filename,
412 plugin->desc.name, filename);
417 GST_LOG ("Plugin %p for file \"%s\" already loaded, returning it now",
422 GST_LOG ("Plugin %p for file \"%s\" prepared, calling entry function...",
425 if (g_module_symbol (module, "plugin_init", &ptr)) {
427 ("plugin %p from file \"%s\" exports a symbol named plugin_init\n",
428 plugin, plugin->filename);
429 g_set_error (error, GST_PLUGIN_ERROR, GST_PLUGIN_ERROR_NAME_MISMATCH,
430 "plugin \"%s\" exports a symbol named plugin_init", desc->name);
433 /* this is where we load the actual .so, so let's trap SIGSEGV */
434 _gst_plugin_fault_handler_setup ();
435 _gst_plugin_fault_handler_filename = plugin->filename;
437 if (gst_plugin_register_func (plugin, module, desc)) {
438 /* remove signal handler */
439 _gst_plugin_fault_handler_restore ();
440 _gst_plugin_fault_handler_filename = NULL;
441 GST_INFO ("plugin \"%s\" loaded", plugin->filename);
444 /* remove signal handler */
445 _gst_plugin_fault_handler_restore ();
446 GST_DEBUG ("gst_plugin_register_func failed for plugin \"%s\"", filename);
450 GST_PLUGIN_ERROR_MODULE,
451 "gst_plugin_register_func failed for plugin \"%s\"", filename);
459 GST_PLUGIN_ERROR_MODULE, "generic load error for \"%s\"", filename);
464 gst_plugin_desc_copy (GstPluginDesc * dest, const GstPluginDesc * src)
466 dest->major_version = src->major_version;
467 dest->minor_version = src->minor_version;
469 dest->name = g_strdup (src->name);
470 g_free (dest->description);
471 dest->description = g_strdup (src->description);
472 dest->plugin_init = src->plugin_init;
473 dest->plugin_exit = src->plugin_exit;
474 g_free (dest->version);
475 dest->version = g_strdup (src->version);
476 g_free (dest->license);
477 dest->license = g_strdup (src->license);
478 g_free (dest->package);
479 dest->package = g_strdup (src->package);
480 g_free (dest->origin);
481 dest->origin = g_strdup (src->origin);
487 gst_plugin_desc_free (GstPluginDesc * desc)
490 g_free (desc->description);
491 g_free (desc->version);
492 g_free (desc->license);
493 g_free (desc->package);
494 g_free (desc->origin);
496 memset (desc, 0, sizeof (GstPluginDesc));
500 * gst_plugin_unload_plugin:
501 * @plugin: The plugin to unload
503 * Unload the given plugin.
505 * Returns: whether or not the plugin unloaded
508 gst_plugin_unload_plugin (GstPlugin * plugin)
510 g_return_val_if_fail (plugin != NULL, FALSE);
515 if (g_module_close (plugin->module)) {
516 plugin->module = NULL;
517 GST_CAT_INFO (GST_CAT_PLUGIN_LOADING, "plugin \"%s\" unloaded",
521 GST_CAT_INFO (GST_CAT_PLUGIN_LOADING, "failed to unload plugin \"%s\"",
528 * gst_plugin_get_name:
529 * @plugin: plugin to get the name of
531 * Get the short name of the plugin
533 * Returns: the name of the plugin
536 gst_plugin_get_name (GstPlugin * plugin)
538 g_return_val_if_fail (plugin != NULL, NULL);
540 return plugin->desc.name;
544 * gst_plugin_get_description:
545 * @plugin: plugin to get long name of
547 * Get the long descriptive name of the plugin
549 * Returns: the long name of the plugin
551 G_CONST_RETURN gchar *
552 gst_plugin_get_description (GstPlugin * plugin)
554 g_return_val_if_fail (plugin != NULL, NULL);
556 return plugin->desc.description;
560 * gst_plugin_get_filename:
561 * @plugin: plugin to get the filename of
563 * get the filename of the plugin
565 * Returns: the filename of the plugin
567 G_CONST_RETURN gchar *
568 gst_plugin_get_filename (GstPlugin * plugin)
570 g_return_val_if_fail (plugin != NULL, NULL);
572 return plugin->filename;
576 * gst_plugin_get_license:
577 * @plugin: plugin to get the license of
579 * get the license of the plugin
581 * Returns: the license of the plugin
583 G_CONST_RETURN gchar *
584 gst_plugin_get_license (GstPlugin * plugin)
586 g_return_val_if_fail (plugin != NULL, NULL);
588 return plugin->desc.license;
592 * gst_plugin_get_package:
593 * @plugin: plugin to get the package of
595 * get the package the plugin belongs to.
597 * Returns: the package of the plugin
599 G_CONST_RETURN gchar *
600 gst_plugin_get_package (GstPlugin * plugin)
602 g_return_val_if_fail (plugin != NULL, NULL);
604 return plugin->desc.package;
608 * gst_plugin_get_origin:
609 * @plugin: plugin to get the origin of
611 * get the URL where the plugin comes from
613 * Returns: the origin of the plugin
615 G_CONST_RETURN gchar *
616 gst_plugin_get_origin (GstPlugin * plugin)
618 g_return_val_if_fail (plugin != NULL, NULL);
620 return plugin->desc.origin;
624 * gst_plugin_get_module:
625 * @plugin: plugin to query
627 * Gets the #GModule of the plugin. If the plugin isn't loaded yet, NULL is
630 * Returns: module belonging to the plugin or NULL if the plugin isn't
634 gst_plugin_get_module (GstPlugin * plugin)
636 g_return_val_if_fail (plugin != NULL, FALSE);
638 return plugin->module;
642 * gst_plugin_is_loaded:
643 * @plugin: plugin to query
645 * queries if the plugin is loaded into memory
647 * Returns: TRUE is loaded, FALSE otherwise
650 gst_plugin_is_loaded (GstPlugin * plugin)
652 g_return_val_if_fail (plugin != NULL, FALSE);
654 return (plugin->module != NULL);
658 * gst_plugin_feature_list:
659 * @plugin: plugin to query
660 * @filter: the filter to use
661 * @first: only return first match
662 * @user_data: user data passed to the filter function
664 * Runs a filter against all plugin features and returns a GList with
665 * the results. If the first flag is set, only the first match is
666 * returned (as a list with a single object).
668 * Returns: a GList of features, g_list_free after use.
671 gst_plugin_feature_filter (GstPlugin * plugin,
672 GstPluginFeatureFilter filter, gboolean first, gpointer user_data)
674 return gst_filter_run (plugin->features, (GstFilterFunc) filter, first,
680 GstPluginFeatureFilter filter;
688 _feature_filter (GstPlugin * plugin, gpointer user_data)
691 FeatureFilterData *data = (FeatureFilterData *) user_data;
694 gst_plugin_feature_filter (plugin, data->filter, data->first,
697 data->result = g_list_concat (data->result, result);
704 * gst_plugin_list_feature_list:
705 * @list: a list of plugins to query
706 * @filter: the filter to use
707 * @first: only return first match
708 * @user_data: user data passed to the filter function
710 * Runs a filter against all plugin features of the plugins in the given
711 * list and returns a GList with the results.
712 * If the first flag is set, only the first match is
713 * returned (as a list with a single object).
715 * Returns: a GList of features, g_list_free after use.
718 gst_plugin_list_feature_filter (GList * list,
719 GstPluginFeatureFilter filter, gboolean first, gpointer user_data)
721 FeatureFilterData data;
724 data.filter = filter;
726 data.user_data = user_data;
729 result = gst_filter_run (list, (GstFilterFunc) _feature_filter, first, &data);
730 g_list_free (result);
736 * gst_plugin_name_filter:
737 * @plugin: the plugin to check
738 * @name: the name of the plugin
740 * A standard filter that returns TRUE when the plugin is of the
743 * Returns: TRUE if the plugin is of the given name.
746 gst_plugin_name_filter (GstPlugin * plugin, const gchar * name)
748 return (plugin->desc.name && !strcmp (plugin->desc.name, name));
752 * gst_plugin_find_feature:
753 * @plugin: plugin to get the feature from
754 * @name: The name of the feature to find
755 * @type: The type of the feature to find
757 * Find a feature of the given name and type in the given plugin.
759 * Returns: a GstPluginFeature or NULL if the feature was not found.
762 gst_plugin_find_feature (GstPlugin * plugin, const gchar * name, GType type)
765 GstPluginFeature *result = NULL;
766 GstTypeNameData data;
768 g_return_val_if_fail (name != NULL, NULL);
773 walk = gst_filter_run (plugin->features,
774 (GstFilterFunc) gst_plugin_feature_type_name_filter, TRUE, &data);
777 result = GST_PLUGIN_FEATURE (walk->data);
783 * gst_plugin_add_feature:
784 * @plugin: plugin to add feature to
785 * @feature: feature to add
787 * Add feature to the list of those provided by the plugin.
788 * There is a separate namespace for each plugin feature type.
789 * See #gst_plugin_get_feature_list
792 gst_plugin_add_feature (GstPlugin * plugin, GstPluginFeature * feature)
794 GstPluginFeature *oldfeature;
796 /* FIXME 0.9: get reference counting somewhat right in here,
797 * GstPluginFeatures should probably be GstObjects that are sinked when
798 * adding them to a plugin */
799 g_return_if_fail (plugin != NULL);
800 g_return_if_fail (GST_IS_PLUGIN_FEATURE (feature));
801 g_return_if_fail (feature != NULL);
803 oldfeature = gst_plugin_find_feature (plugin,
804 GST_PLUGIN_FEATURE_NAME (feature), G_OBJECT_TYPE (feature));
806 if (oldfeature == feature) {
807 GST_WARNING ("feature %s has already been added",
808 GST_PLUGIN_FEATURE_NAME (feature));
809 /* g_object_unref (feature); */
810 } else if (oldfeature) {
811 GST_WARNING ("feature %s already present in plugin",
812 GST_PLUGIN_FEATURE_NAME (feature));
813 /* g_object_unref (feature); */
815 feature->manager = plugin;
816 plugin->features = g_list_prepend (plugin->features, feature);
817 plugin->numfeatures++;
822 * gst_plugin_get_feature_list:
823 * @plugin: the plugin to get the features from
825 * get a list of all the features that this plugin provides
827 * Returns: a GList of features, use g_list_free to free the list.
830 gst_plugin_get_feature_list (GstPlugin * plugin)
832 g_return_val_if_fail (plugin != NULL, NULL);
834 return g_list_copy (plugin->features);
839 * @name: name of plugin to load
841 * Load the named plugin.
843 * Returns: whether the plugin was loaded or not
846 gst_plugin_load (const gchar * name)
849 GError *error = NULL;
851 plugin = gst_registry_pool_find_plugin (name);
853 gst_plugin_load_file (plugin->filename, &error);
855 GST_WARNING ("load_plugin error: %s\n", error->message);
856 g_error_free (error);
862 GST_DEBUG ("Could not find %s in registry pool", name);
868 * @name: name of library to load
870 * Load the named library. Name should be given as
871 * "liblibrary.so".
873 * Returns: whether the library was loaded or not
876 gst_library_load (const gchar * name)
880 /* for now this is the same */
881 res = gst_plugin_load (name);