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"
42 #include "gstfilter.h"
43 #include "gstregistry.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 GstPlugin *gst_plugin_register_func (GstPlugin * plugin,
78 GModule * module, GstPluginDesc * desc);
80 gst_plugin_desc_copy (GstPluginDesc * dest, const GstPluginDesc * src);
83 G_DEFINE_TYPE (GstPlugin, gst_plugin, G_TYPE_OBJECT);
86 gst_plugin_init (GstPlugin * plugin)
92 gst_plugin_class_init (GstPluginClass * klass)
99 gst_plugin_error_quark (void)
101 static GQuark quark = 0;
104 quark = g_quark_from_static_string ("gst_plugin_error");
108 /* this function can be called in the GCC constructor extension, before
109 * the _gst_plugin_initialize() was called. In that case, we store the
110 * plugin description in a list to initialize it when we open the main
112 * When the main module is known, we can register the plugin right away.
115 _gst_plugin_register_static (GstPluginDesc * desc)
117 if (main_module == NULL) {
119 GST_LOG ("queueing static plugin \"%s\" for loading later on",
121 _gst_plugin_static = g_list_prepend (_gst_plugin_static, desc);
126 GST_LOG ("attempting to load static plugin \"%s\" now...", desc->name);
127 plugin = g_object_new (GST_TYPE_PLUGIN, NULL);
128 if (gst_plugin_register_func (plugin, main_module, desc)) {
130 GST_INFO ("loaded static plugin \"%s\"", desc->name);
131 gst_default_registry_add_plugin (plugin);
137 _gst_plugin_initialize (void)
139 main_module = g_module_open (NULL, G_MODULE_BIND_LAZY);
141 /* now register all static plugins */
142 g_list_foreach (_gst_plugin_static, (GFunc) _gst_plugin_register_static,
146 /* this function could be extended to check if the plugin license matches the
147 * applications license (would require the app to register its license somehow).
148 * We'll wait for someone who's interested in it to code it :)
151 gst_plugin_check_license (const gchar * license)
153 gchar **check_license = valid_licenses;
155 g_assert (check_license);
157 while (*check_license) {
158 if (strcmp (license, *check_license) == 0)
166 gst_plugin_check_version (gint major, gint minor)
168 /* return NULL if the major and minor version numbers are not compatible */
170 if (major != GST_VERSION_MAJOR || minor != GST_VERSION_MINOR)
177 gst_plugin_register_func (GstPlugin * plugin, GModule * module,
178 GstPluginDesc * desc)
180 if (!gst_plugin_check_version (desc->major_version, desc->minor_version)) {
182 GST_INFO ("plugin \"%s\" has incompatible version, not loading",
187 if (!desc->license || !desc->description || !desc->source ||
188 !desc->package || !desc->origin) {
190 GST_INFO ("plugin \"%s\" has incorrect GstPluginDesc, not loading",
195 if (!gst_plugin_check_license (desc->license)) {
197 GST_INFO ("plugin \"%s\" has invalid license \"%s\", not loading",
198 plugin->filename, desc->license);
203 GST_LOG ("plugin \"%s\" looks good", GST_STR_NULL (plugin->filename));
205 gst_plugin_desc_copy (&plugin->desc, desc);
207 if (!((desc->plugin_init) (plugin))) {
209 GST_INFO ("plugin \"%s\" failed to initialise", plugin->filename);
210 plugin->module = NULL;
215 GST_LOG ("plugin \"%s\" initialised", GST_STR_NULL (plugin->filename));
222 * _gst_plugin_fault_handler_restore:
223 * segfault handler restorer
226 _gst_plugin_fault_handler_restore (void)
228 struct sigaction action;
230 memset (&action, 0, sizeof (action));
231 action.sa_handler = SIG_DFL;
233 sigaction (SIGSEGV, &action, NULL);
237 * _gst_plugin_fault_handler_sighandler:
238 * segfault handler implementation
241 _gst_plugin_fault_handler_sighandler (int signum)
243 /* We need to restore the fault handler or we'll keep getting it */
244 _gst_plugin_fault_handler_restore ();
248 g_print ("\nERROR: ");
249 g_print ("Caught a segmentation fault while loading plugin file:\n");
250 g_print ("%s\n\n", _gst_plugin_fault_handler_filename);
251 g_print ("Please either:\n");
252 g_print ("- remove it and restart.\n");
253 g_print ("- run with --gst-disable-segtrap and debug.\n");
257 g_print ("Caught unhandled signal on plugin loading\n");
263 * _gst_plugin_fault_handler_setup:
264 * sets up the segfault handler
267 _gst_plugin_fault_handler_setup (void)
269 struct sigaction action;
271 /* if asked to leave segfaults alone, just return */
272 if (_gst_disable_segtrap)
275 if (_gst_plugin_fault_handler_is_setup)
278 memset (&action, 0, sizeof (action));
279 action.sa_handler = _gst_plugin_fault_handler_sighandler;
281 sigaction (SIGSEGV, &action, NULL);
285 _gst_plugin_fault_handler_restore (void)
290 _gst_plugin_fault_handler_setup (void)
295 static void _gst_plugin_fault_handler_setup ();
298 * gst_plugin_load_file:
299 * @filename: the plugin filename to load
300 * @error: pointer to a NULL-valued GError
302 * Loads the given plugin.
304 * Returns: a new GstPlugin or NULL, if an error occurred.
307 gst_plugin_load_file (const gchar * filename, GError ** error)
313 struct stat file_status;
315 g_return_val_if_fail (filename != NULL, NULL);
317 plugin = gst_registry_lookup (gst_registry_get_default (), filename);
318 if (plugin && plugin->module) {
322 GST_CAT_DEBUG (GST_CAT_PLUGIN_LOADING, "attempt to load plugin \"%s\"",
325 if (g_module_supported () == FALSE) {
326 GST_CAT_DEBUG (GST_CAT_PLUGIN_LOADING, "module loading not supported");
329 GST_PLUGIN_ERROR_MODULE, "Dynamic loading not supported");
333 if (stat (filename, &file_status)) {
334 GST_CAT_DEBUG (GST_CAT_PLUGIN_LOADING, "problem accessing file");
337 GST_PLUGIN_ERROR_MODULE, "Problem accessing file %s: %s\n", filename,
342 module = g_module_open (filename, G_MODULE_BIND_LOCAL);
343 if (module == NULL) {
344 GST_CAT_ERROR (GST_CAT_PLUGIN_LOADING, "module_open failed: %s",
347 GST_PLUGIN_ERROR, GST_PLUGIN_ERROR_MODULE, "Opening module failed");
351 plugin = g_object_new (GST_TYPE_PLUGIN, NULL);
353 plugin->module = module;
354 plugin->filename = strdup (filename);
355 plugin->file_mtime = file_status.st_mtime;
356 plugin->file_size = file_status.st_size;
358 ret = g_module_symbol (module, "gst_plugin_desc", &ptr);
360 GST_DEBUG ("Could not find plugin entry point in \"%s\"", filename);
363 GST_PLUGIN_ERROR_MODULE,
364 "Could not find plugin entry point in \"%s\"", filename);
365 g_object_unref (plugin);
368 plugin->orig_desc = (GstPluginDesc *) ptr;
370 GST_LOG ("Plugin %p for file \"%s\" prepared, calling entry function...",
373 /* this is where we load the actual .so, so let's trap SIGSEGV */
374 _gst_plugin_fault_handler_setup ();
375 _gst_plugin_fault_handler_filename = plugin->filename;
377 GST_LOG ("Plugin %p for file \"%s\" prepared, registering...",
380 if (!gst_plugin_register_func (plugin, module, plugin->orig_desc)) {
381 /* remove signal handler */
382 _gst_plugin_fault_handler_restore ();
383 GST_DEBUG ("gst_plugin_register_func failed for plugin \"%s\"", filename);
387 GST_PLUGIN_ERROR_MODULE,
388 "gst_plugin_register_func failed for plugin \"%s\"", filename);
389 g_module_close (module);
393 /* remove signal handler */
394 _gst_plugin_fault_handler_restore ();
395 _gst_plugin_fault_handler_filename = NULL;
396 GST_INFO ("plugin \"%s\" loaded", plugin->filename);
398 gst_default_registry_add_plugin (plugin);
404 gst_plugin_desc_copy (GstPluginDesc * dest, const GstPluginDesc * src)
406 dest->major_version = src->major_version;
407 dest->minor_version = src->minor_version;
409 dest->name = g_strdup (src->name);
410 g_free (dest->description);
411 dest->description = g_strdup (src->description);
412 dest->plugin_init = src->plugin_init;
413 g_free (dest->version);
414 dest->version = g_strdup (src->version);
415 g_free (dest->license);
416 dest->license = g_strdup (src->license);
417 g_free (dest->source);
418 dest->source = g_strdup (src->source);
419 g_free (dest->package);
420 dest->package = g_strdup (src->package);
421 g_free (dest->origin);
422 dest->origin = g_strdup (src->origin);
428 gst_plugin_desc_free (GstPluginDesc * desc)
431 g_free (desc->description);
432 g_free (desc->version);
433 g_free (desc->license);
434 g_free (desc->source);
435 g_free (desc->package);
436 g_free (desc->origin);
438 memset (desc, 0, sizeof (GstPluginDesc));
442 * gst_plugin_unload_plugin:
443 * @plugin: The plugin to unload
445 * Unload the given plugin.
447 * Returns: whether or not the plugin unloaded
450 gst_plugin_unload_plugin (GstPlugin * plugin)
452 g_return_val_if_fail (plugin != NULL, FALSE);
457 if (g_module_close (plugin->module)) {
458 plugin->module = NULL;
459 GST_CAT_INFO (GST_CAT_PLUGIN_LOADING, "plugin \"%s\" unloaded",
463 GST_CAT_INFO (GST_CAT_PLUGIN_LOADING, "failed to unload plugin \"%s\"",
470 * gst_plugin_get_name:
471 * @plugin: plugin to get the name of
473 * Get the short name of the plugin
475 * Returns: the name of the plugin
478 gst_plugin_get_name (GstPlugin * plugin)
480 g_return_val_if_fail (plugin != NULL, NULL);
482 return plugin->desc.name;
486 * gst_plugin_get_description:
487 * @plugin: plugin to get long name of
489 * Get the long descriptive name of the plugin
491 * Returns: the long name of the plugin
493 G_CONST_RETURN gchar *
494 gst_plugin_get_description (GstPlugin * plugin)
496 g_return_val_if_fail (plugin != NULL, NULL);
498 return plugin->desc.description;
502 * gst_plugin_get_filename:
503 * @plugin: plugin to get the filename of
505 * get the filename of the plugin
507 * Returns: the filename of the plugin
509 G_CONST_RETURN gchar *
510 gst_plugin_get_filename (GstPlugin * plugin)
512 g_return_val_if_fail (plugin != NULL, NULL);
514 return plugin->filename;
518 * gst_plugin_get_version:
519 * @plugin: plugin to get the version of
521 * get the version of the plugin
523 * Returns: the version of the plugin
525 G_CONST_RETURN gchar *
526 gst_plugin_get_version (GstPlugin * plugin)
528 g_return_val_if_fail (plugin != NULL, NULL);
530 return plugin->desc.version;
534 * gst_plugin_get_license:
535 * @plugin: plugin to get the license of
537 * get the license of the plugin
539 * Returns: the license of the plugin
541 G_CONST_RETURN gchar *
542 gst_plugin_get_license (GstPlugin * plugin)
544 g_return_val_if_fail (plugin != NULL, NULL);
546 return plugin->desc.license;
550 * gst_plugin_get_source:
551 * @plugin: plugin to get the source of
553 * get the source module the plugin belongs to.
555 * Returns: the source of the plugin
557 G_CONST_RETURN gchar *
558 gst_plugin_get_source (GstPlugin * plugin)
560 g_return_val_if_fail (plugin != NULL, NULL);
562 return plugin->desc.source;
566 * gst_plugin_get_package:
567 * @plugin: plugin to get the package of
569 * get the package the plugin belongs to.
571 * Returns: the package of the plugin
573 G_CONST_RETURN gchar *
574 gst_plugin_get_package (GstPlugin * plugin)
576 g_return_val_if_fail (plugin != NULL, NULL);
578 return plugin->desc.package;
582 * gst_plugin_get_origin:
583 * @plugin: plugin to get the origin of
585 * get the URL where the plugin comes from
587 * Returns: the origin of the plugin
589 G_CONST_RETURN gchar *
590 gst_plugin_get_origin (GstPlugin * plugin)
592 g_return_val_if_fail (plugin != NULL, NULL);
594 return plugin->desc.origin;
598 * gst_plugin_get_module:
599 * @plugin: plugin to query
601 * Gets the #GModule of the plugin. If the plugin isn't loaded yet, NULL is
604 * Returns: module belonging to the plugin or NULL if the plugin isn't
608 gst_plugin_get_module (GstPlugin * plugin)
610 g_return_val_if_fail (plugin != NULL, NULL);
612 return plugin->module;
616 * gst_plugin_is_loaded:
617 * @plugin: plugin to query
619 * queries if the plugin is loaded into memory
621 * Returns: TRUE is loaded, FALSE otherwise
624 gst_plugin_is_loaded (GstPlugin * plugin)
626 g_return_val_if_fail (plugin != NULL, FALSE);
628 return (plugin->module != NULL);
632 * gst_plugin_feature_list:
633 * @plugin: plugin to query
634 * @filter: the filter to use
635 * @first: only return first match
636 * @user_data: user data passed to the filter function
638 * Runs a filter against all plugin features and returns a GList with
639 * the results. If the first flag is set, only the first match is
640 * returned (as a list with a single object).
642 * Returns: a GList of features, g_list_free after use.
645 gst_plugin_feature_filter (GstPlugin * plugin,
646 GstPluginFeatureFilter filter, gboolean first, gpointer user_data)
648 return gst_filter_run (plugin->features, (GstFilterFunc) filter, first,
654 GstPluginFeatureFilter filter;
662 _feature_filter (GstPlugin * plugin, gpointer user_data)
665 FeatureFilterData *data = (FeatureFilterData *) user_data;
668 gst_plugin_feature_filter (plugin, data->filter, data->first,
671 data->result = g_list_concat (data->result, result);
678 * gst_plugin_list_feature_filter:
679 * @list: a #GList of plugins to query
680 * @filter: the filter function to use
681 * @first: only return first match
682 * @user_data: user data passed to the filter function
684 * Runs a filter against all plugin features of the plugins in the given
685 * list and returns a GList with the results.
686 * If the first flag is set, only the first match is
687 * returned (as a list with a single object).
689 * Returns: a GList of features, g_list_free after use.
692 gst_plugin_list_feature_filter (GList * list,
693 GstPluginFeatureFilter filter, gboolean first, gpointer user_data)
695 FeatureFilterData data;
698 data.filter = filter;
700 data.user_data = user_data;
703 result = gst_filter_run (list, (GstFilterFunc) _feature_filter, first, &data);
704 g_list_free (result);
710 * gst_plugin_name_filter:
711 * @plugin: the plugin to check
712 * @name: the name of the plugin
714 * A standard filter that returns TRUE when the plugin is of the
717 * Returns: TRUE if the plugin is of the given name.
720 gst_plugin_name_filter (GstPlugin * plugin, const gchar * name)
722 return (plugin->desc.name && !strcmp (plugin->desc.name, name));
726 * gst_plugin_find_feature:
727 * @plugin: plugin to get the feature from
728 * @name: The name of the feature to find
729 * @type: The type of the feature to find
731 * Find a feature of the given name and type in the given plugin.
733 * Returns: a GstPluginFeature or NULL if the feature was not found.
736 gst_plugin_find_feature (GstPlugin * plugin, const gchar * name, GType type)
739 GstPluginFeature *result = NULL;
740 GstTypeNameData data;
742 g_return_val_if_fail (name != NULL, NULL);
747 walk = gst_filter_run (plugin->features,
748 (GstFilterFunc) gst_plugin_feature_type_name_filter, TRUE, &data);
751 result = GST_PLUGIN_FEATURE (walk->data);
759 gst_plugin_feature_name_filter (GstPluginFeature * feature, const gchar * name)
761 return !strcmp (name, GST_PLUGIN_FEATURE_NAME (feature));
765 * gst_plugin_find_feature_by_name:
766 * @plugin: plugin to get the feature from
767 * @name: The name of the feature to find
769 * Find a feature of the given name in the given plugin.
771 * Returns: a GstPluginFeature or NULL if the feature was not found.
774 gst_plugin_find_feature_by_name (GstPlugin * plugin, const gchar * name)
777 GstPluginFeature *result = NULL;
779 g_return_val_if_fail (name != NULL, NULL);
781 walk = gst_filter_run (plugin->features,
782 (GstFilterFunc) gst_plugin_feature_name_filter, TRUE, (void *) name);
785 result = GST_PLUGIN_FEATURE (walk->data);
793 * gst_plugin_add_feature:
794 * @plugin: plugin to add feature to
795 * @feature: feature to add
797 * Add feature to the list of those provided by the plugin.
798 * There is a separate namespace for each plugin feature type.
799 * See #gst_plugin_get_feature_list
802 gst_plugin_add_feature (GstPlugin * plugin, GstPluginFeature * feature)
804 GstPluginFeature *oldfeature;
806 /* FIXME 0.9: get reference counting somewhat right in here,
807 * GstPluginFeatures should probably be GstObjects that are sinked when
808 * adding them to a plugin */
809 g_return_if_fail (plugin != NULL);
810 g_return_if_fail (GST_IS_PLUGIN_FEATURE (feature));
811 g_return_if_fail (feature != NULL);
813 oldfeature = gst_plugin_find_feature (plugin,
814 GST_PLUGIN_FEATURE_NAME (feature), G_OBJECT_TYPE (feature));
816 if (oldfeature == feature) {
817 GST_WARNING ("feature %s has already been added",
818 GST_PLUGIN_FEATURE_NAME (feature));
819 /* g_object_unref (feature); */
820 } else if (oldfeature) {
821 GST_WARNING ("feature %s already present in plugin",
822 GST_PLUGIN_FEATURE_NAME (feature));
823 /* g_object_unref (feature); */
825 feature->plugin = plugin;
826 plugin->features = g_list_prepend (plugin->features, feature);
827 plugin->numfeatures++;
832 * gst_plugin_get_feature_list:
833 * @plugin: the plugin to get the features from
835 * get a list of all the features that this plugin provides
837 * Returns: a GList of features, use g_list_free to free the list.
840 gst_plugin_get_feature_list (GstPlugin * plugin)
842 g_return_val_if_fail (plugin != NULL, NULL);
844 return g_list_copy (plugin->features);
849 * @name: name of plugin to load
851 * Load the named plugin.
853 * Returns: whether the plugin was loaded or not
856 gst_plugin_load_1 (const gchar * name)
859 GError *error = NULL;
861 plugin = gst_registry_find_plugin (gst_registry_get_default (), name);
863 plugin = gst_plugin_load_file (plugin->filename, &error);
865 GST_WARNING ("load_plugin error: %s\n", error->message);
866 g_error_free (error);
872 GST_DEBUG ("Could not find %s in registry pool", name);
877 gst_plugin_load (GstPlugin * plugin)
879 GError *error = NULL;
881 if (gst_plugin_is_loaded (plugin)) {
885 if (!plugin->filename) {
889 plugin = gst_plugin_load_file (plugin->filename, &error);
891 GST_WARNING ("load_plugin error: %s\n", error->message);
892 g_error_free (error);