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->source ||
194 !desc->package || !desc->origin) {
196 GST_INFO ("plugin \"%s\" has incorrect GstPluginDesc, not loading",
201 if (!gst_plugin_check_license (desc->license)) {
203 GST_INFO ("plugin \"%s\" has invalid license \"%s\", not loading",
204 plugin->filename, desc->license);
209 GST_LOG ("plugin \"%s\" looks good", GST_STR_NULL (plugin->filename));
211 gst_plugin_desc_copy (&plugin->desc, desc);
212 plugin->module = module;
214 if (!((desc->plugin_init) (plugin))) {
216 GST_INFO ("plugin \"%s\" failed to initialise", plugin->filename);
217 plugin->module = NULL;
222 GST_LOG ("plugin \"%s\" initialised", GST_STR_NULL (plugin->filename));
229 * _gst_plugin_fault_handler_restore:
230 * segfault handler restorer
233 _gst_plugin_fault_handler_restore (void)
235 struct sigaction action;
237 memset (&action, 0, sizeof (action));
238 action.sa_handler = SIG_DFL;
240 sigaction (SIGSEGV, &action, NULL);
244 * _gst_plugin_fault_handler_sighandler:
245 * segfault handler implementation
248 _gst_plugin_fault_handler_sighandler (int signum)
250 /* We need to restore the fault handler or we'll keep getting it */
251 _gst_plugin_fault_handler_restore ();
255 g_print ("\nERROR: ");
256 g_print ("Caught a segmentation fault while loading plugin file:\n");
257 g_print ("%s\n\n", _gst_plugin_fault_handler_filename);
258 g_print ("Please either:\n");
259 g_print ("- remove it and restart.\n");
260 g_print ("- run with --gst-disable-segtrap and debug.\n");
264 g_print ("Caught unhandled signal on plugin loading\n");
270 * _gst_plugin_fault_handler_setup:
271 * sets up the segfault handler
274 _gst_plugin_fault_handler_setup (void)
276 struct sigaction action;
278 /* if asked to leave segfaults alone, just return */
279 if (_gst_disable_segtrap)
282 if (_gst_plugin_fault_handler_is_setup)
285 memset (&action, 0, sizeof (action));
286 action.sa_handler = _gst_plugin_fault_handler_sighandler;
288 sigaction (SIGSEGV, &action, NULL);
292 _gst_plugin_fault_handler_restore (void)
297 _gst_plugin_fault_handler_setup (void)
302 static void _gst_plugin_fault_handler_setup ();
305 * gst_plugin_check_module:
306 * @module: GModule handle to check for pluginness
307 * @error: pointer to a NULL-valued GError
308 * @pptr: pointer to a gpointer used to return the gst_plugin_desc symbol
311 * Checks if the given module is a GStreamer plugin
313 * Returns: TRUE if the given module is a GStreamer plugin
316 gst_plugin_check_module (GModule * module, const char *filename,
317 GError ** error, gpointer * pptr)
324 if (module == NULL) {
325 GST_DEBUG ("Error loading plugin %s, reason: %s", filename,
327 g_set_error (error, GST_PLUGIN_ERROR, GST_PLUGIN_ERROR_MODULE,
328 "Error loading plugin %s, reason: %s", filename, g_module_error ());
332 if (!g_module_symbol (module, "gst_plugin_desc", pptr)) {
333 GST_DEBUG ("Could not find plugin entry point in \"%s\"", filename);
336 GST_PLUGIN_ERROR_MODULE,
337 "Could not find plugin entry point in \"%s\"", filename);
345 * gst_plugin_check_file:
346 * @filename: the plugin filename to check for pluginness
347 * @error: pointer to a NULL-valued GError
349 * Checks if the given path represents a GStreamer plugin.
351 * Returns: TRUE if the given path is a GStreamer plugin.
354 gst_plugin_check_file (const gchar * filename, GError ** error)
357 struct stat file_status;
360 g_return_val_if_fail (filename != NULL, FALSE);
362 if (g_module_supported () == FALSE) {
365 GST_PLUGIN_ERROR_MODULE, "Dynamic loading not supported");
369 if (stat (filename, &file_status)) {
372 GST_PLUGIN_ERROR_MODULE, "Problem accessing file %s: %s\n", filename,
377 module = g_module_open (filename, G_MODULE_BIND_LAZY | G_MODULE_BIND_LOCAL);
382 check = gst_plugin_check_module (module, filename, error, NULL);
383 g_module_close (module);
386 GST_INFO ("file \"%s\" %s look like a gst plugin", filename,
387 check ? "does" : "doesn't");
393 * gst_plugin_load_file:
394 * @filename: the plugin filename to load
395 * @error: pointer to a NULL-valued GError
397 * Loads the given plugin.
399 * Returns: a new GstPlugin or NULL, if an error occurred.
402 gst_plugin_load_file (const gchar * filename, GError ** error)
407 gboolean free_plugin;
410 g_return_val_if_fail (filename != NULL, NULL);
412 GST_CAT_DEBUG (GST_CAT_PLUGIN_LOADING, "attempt to load plugin \"%s\"",
415 module = g_module_open (filename, G_MODULE_BIND_LAZY | G_MODULE_BIND_LOCAL);
417 /* gst_plugin_check_module handles module == NULL case */
418 if (!gst_plugin_check_module (module, filename, error, &ptr)) {
420 g_module_close (module);
424 desc = (GstPluginDesc *) ptr;
426 plugin = gst_registry_pool_find_plugin (desc->name);
429 plugin = g_new0 (GstPlugin, 1);
430 plugin->filename = g_strdup (filename);
431 GST_DEBUG ("created new GstPlugin %p for file \"%s\"", plugin, filename);
434 if (gst_plugin_is_loaded (plugin)) {
435 g_module_close (module);
436 if (plugin->filename && strcmp (plugin->filename, filename) != 0) {
438 ("plugin %p from file \"%s\" with same name %s is already "
439 "loaded, aborting loading of \"%s\"", plugin, plugin->filename,
440 plugin->desc.name, filename);
441 g_set_error (error, GST_PLUGIN_ERROR,
442 GST_PLUGIN_ERROR_NAME_MISMATCH,
443 "plugin %p from file \"%s\" with same name %s is already "
444 "loaded, aborting loading of \"%s\"", plugin, plugin->filename,
445 plugin->desc.name, filename);
450 GST_LOG ("Plugin %p for file \"%s\" already loaded, returning it now",
455 GST_LOG ("Plugin %p for file \"%s\" prepared, calling entry function...",
458 if (g_module_symbol (module, "plugin_init", &ptr)) {
460 ("plugin %p from file \"%s\" exports a symbol named plugin_init\n",
461 plugin, plugin->filename);
462 g_set_error (error, GST_PLUGIN_ERROR, GST_PLUGIN_ERROR_NAME_MISMATCH,
463 "plugin \"%s\" exports a symbol named plugin_init", desc->name);
466 /* this is where we load the actual .so, so let's trap SIGSEGV */
467 _gst_plugin_fault_handler_setup ();
468 _gst_plugin_fault_handler_filename = plugin->filename;
470 GST_LOG ("Plugin %p for file \"%s\" prepared, registering...",
473 if (gst_plugin_register_func (plugin, module, desc)) {
474 /* remove signal handler */
475 _gst_plugin_fault_handler_restore ();
476 _gst_plugin_fault_handler_filename = NULL;
477 GST_INFO ("plugin \"%s\" loaded", plugin->filename);
480 /* remove signal handler */
481 _gst_plugin_fault_handler_restore ();
482 GST_DEBUG ("gst_plugin_register_func failed for plugin \"%s\"", filename);
486 GST_PLUGIN_ERROR_MODULE,
487 "gst_plugin_register_func failed for plugin \"%s\"", filename);
488 g_module_close (module);
496 gst_plugin_desc_copy (GstPluginDesc * dest, const GstPluginDesc * src)
498 dest->major_version = src->major_version;
499 dest->minor_version = src->minor_version;
501 dest->name = g_strdup (src->name);
502 g_free (dest->description);
503 dest->description = g_strdup (src->description);
504 dest->plugin_init = src->plugin_init;
505 dest->plugin_exit = src->plugin_exit;
506 g_free (dest->version);
507 dest->version = g_strdup (src->version);
508 g_free (dest->license);
509 dest->license = g_strdup (src->license);
510 g_free (dest->source);
511 dest->source = g_strdup (src->source);
512 g_free (dest->package);
513 dest->package = g_strdup (src->package);
514 g_free (dest->origin);
515 dest->origin = g_strdup (src->origin);
521 gst_plugin_desc_free (GstPluginDesc * desc)
524 g_free (desc->description);
525 g_free (desc->version);
526 g_free (desc->license);
527 g_free (desc->source);
528 g_free (desc->package);
529 g_free (desc->origin);
531 memset (desc, 0, sizeof (GstPluginDesc));
535 * gst_plugin_unload_plugin:
536 * @plugin: The plugin to unload
538 * Unload the given plugin.
540 * Returns: whether or not the plugin unloaded
543 gst_plugin_unload_plugin (GstPlugin * plugin)
545 g_return_val_if_fail (plugin != NULL, FALSE);
550 if (g_module_close (plugin->module)) {
551 plugin->module = NULL;
552 GST_CAT_INFO (GST_CAT_PLUGIN_LOADING, "plugin \"%s\" unloaded",
556 GST_CAT_INFO (GST_CAT_PLUGIN_LOADING, "failed to unload plugin \"%s\"",
563 * gst_plugin_get_name:
564 * @plugin: plugin to get the name of
566 * Get the short name of the plugin
568 * Returns: the name of the plugin
571 gst_plugin_get_name (GstPlugin * plugin)
573 g_return_val_if_fail (plugin != NULL, NULL);
575 return plugin->desc.name;
579 * gst_plugin_get_description:
580 * @plugin: plugin to get long name of
582 * Get the long descriptive name of the plugin
584 * Returns: the long name of the plugin
586 G_CONST_RETURN gchar *
587 gst_plugin_get_description (GstPlugin * plugin)
589 g_return_val_if_fail (plugin != NULL, NULL);
591 return plugin->desc.description;
595 * gst_plugin_get_filename:
596 * @plugin: plugin to get the filename of
598 * get the filename of the plugin
600 * Returns: the filename of the plugin
602 G_CONST_RETURN gchar *
603 gst_plugin_get_filename (GstPlugin * plugin)
605 g_return_val_if_fail (plugin != NULL, NULL);
607 return plugin->filename;
611 * gst_plugin_get_version:
612 * @plugin: plugin to get the version of
614 * get the version of the plugin
616 * Returns: the version of the plugin
618 G_CONST_RETURN gchar *
619 gst_plugin_get_version (GstPlugin * plugin)
621 g_return_val_if_fail (plugin != NULL, NULL);
623 return plugin->desc.version;
627 * gst_plugin_get_license:
628 * @plugin: plugin to get the license of
630 * get the license of the plugin
632 * Returns: the license of the plugin
634 G_CONST_RETURN gchar *
635 gst_plugin_get_license (GstPlugin * plugin)
637 g_return_val_if_fail (plugin != NULL, NULL);
639 return plugin->desc.license;
643 * gst_plugin_get_source:
644 * @plugin: plugin to get the source of
646 * get the source module the plugin belongs to.
648 * Returns: the source of the plugin
650 G_CONST_RETURN gchar *
651 gst_plugin_get_source (GstPlugin * plugin)
653 g_return_val_if_fail (plugin != NULL, NULL);
655 return plugin->desc.source;
659 * gst_plugin_get_package:
660 * @plugin: plugin to get the package of
662 * get the package the plugin belongs to.
664 * Returns: the package of the plugin
666 G_CONST_RETURN gchar *
667 gst_plugin_get_package (GstPlugin * plugin)
669 g_return_val_if_fail (plugin != NULL, NULL);
671 return plugin->desc.package;
675 * gst_plugin_get_origin:
676 * @plugin: plugin to get the origin of
678 * get the URL where the plugin comes from
680 * Returns: the origin of the plugin
682 G_CONST_RETURN gchar *
683 gst_plugin_get_origin (GstPlugin * plugin)
685 g_return_val_if_fail (plugin != NULL, NULL);
687 return plugin->desc.origin;
691 * gst_plugin_get_module:
692 * @plugin: plugin to query
694 * Gets the #GModule of the plugin. If the plugin isn't loaded yet, NULL is
697 * Returns: module belonging to the plugin or NULL if the plugin isn't
701 gst_plugin_get_module (GstPlugin * plugin)
703 g_return_val_if_fail (plugin != NULL, NULL);
705 return plugin->module;
709 * gst_plugin_is_loaded:
710 * @plugin: plugin to query
712 * queries if the plugin is loaded into memory
714 * Returns: TRUE is loaded, FALSE otherwise
717 gst_plugin_is_loaded (GstPlugin * plugin)
719 g_return_val_if_fail (plugin != NULL, FALSE);
721 return (plugin->module != NULL);
725 * gst_plugin_feature_list:
726 * @plugin: plugin to query
727 * @filter: the filter to use
728 * @first: only return first match
729 * @user_data: user data passed to the filter function
731 * Runs a filter against all plugin features and returns a GList with
732 * the results. If the first flag is set, only the first match is
733 * returned (as a list with a single object).
735 * Returns: a GList of features, g_list_free after use.
738 gst_plugin_feature_filter (GstPlugin * plugin,
739 GstPluginFeatureFilter filter, gboolean first, gpointer user_data)
741 return gst_filter_run (plugin->features, (GstFilterFunc) filter, first,
747 GstPluginFeatureFilter filter;
755 _feature_filter (GstPlugin * plugin, gpointer user_data)
758 FeatureFilterData *data = (FeatureFilterData *) user_data;
761 gst_plugin_feature_filter (plugin, data->filter, data->first,
764 data->result = g_list_concat (data->result, result);
771 * gst_plugin_list_feature_filter:
772 * @list: a #GList of plugins to query
773 * @filter: the filter function to use
774 * @first: only return first match
775 * @user_data: user data passed to the filter function
777 * Runs a filter against all plugin features of the plugins in the given
778 * list and returns a GList with the results.
779 * If the first flag is set, only the first match is
780 * returned (as a list with a single object).
782 * Returns: a GList of features, g_list_free after use.
785 gst_plugin_list_feature_filter (GList * list,
786 GstPluginFeatureFilter filter, gboolean first, gpointer user_data)
788 FeatureFilterData data;
791 data.filter = filter;
793 data.user_data = user_data;
796 result = gst_filter_run (list, (GstFilterFunc) _feature_filter, first, &data);
797 g_list_free (result);
803 * gst_plugin_name_filter:
804 * @plugin: the plugin to check
805 * @name: the name of the plugin
807 * A standard filter that returns TRUE when the plugin is of the
810 * Returns: TRUE if the plugin is of the given name.
813 gst_plugin_name_filter (GstPlugin * plugin, const gchar * name)
815 return (plugin->desc.name && !strcmp (plugin->desc.name, name));
819 * gst_plugin_find_feature:
820 * @plugin: plugin to get the feature from
821 * @name: The name of the feature to find
822 * @type: The type of the feature to find
824 * Find a feature of the given name and type in the given plugin.
826 * Returns: a GstPluginFeature or NULL if the feature was not found.
829 gst_plugin_find_feature (GstPlugin * plugin, const gchar * name, GType type)
832 GstPluginFeature *result = NULL;
833 GstTypeNameData data;
835 g_return_val_if_fail (name != NULL, NULL);
840 walk = gst_filter_run (plugin->features,
841 (GstFilterFunc) gst_plugin_feature_type_name_filter, TRUE, &data);
844 result = GST_PLUGIN_FEATURE (walk->data);
850 * gst_plugin_add_feature:
851 * @plugin: plugin to add feature to
852 * @feature: feature to add
854 * Add feature to the list of those provided by the plugin.
855 * There is a separate namespace for each plugin feature type.
856 * See #gst_plugin_get_feature_list
859 gst_plugin_add_feature (GstPlugin * plugin, GstPluginFeature * feature)
861 GstPluginFeature *oldfeature;
863 /* FIXME 0.9: get reference counting somewhat right in here,
864 * GstPluginFeatures should probably be GstObjects that are sinked when
865 * adding them to a plugin */
866 g_return_if_fail (plugin != NULL);
867 g_return_if_fail (GST_IS_PLUGIN_FEATURE (feature));
868 g_return_if_fail (feature != NULL);
870 oldfeature = gst_plugin_find_feature (plugin,
871 GST_PLUGIN_FEATURE_NAME (feature), G_OBJECT_TYPE (feature));
873 if (oldfeature == feature) {
874 GST_WARNING ("feature %s has already been added",
875 GST_PLUGIN_FEATURE_NAME (feature));
876 /* g_object_unref (feature); */
877 } else if (oldfeature) {
878 GST_WARNING ("feature %s already present in plugin",
879 GST_PLUGIN_FEATURE_NAME (feature));
880 /* g_object_unref (feature); */
882 feature->manager = plugin;
883 plugin->features = g_list_prepend (plugin->features, feature);
884 plugin->numfeatures++;
889 * gst_plugin_get_feature_list:
890 * @plugin: the plugin to get the features from
892 * get a list of all the features that this plugin provides
894 * Returns: a GList of features, use g_list_free to free the list.
897 gst_plugin_get_feature_list (GstPlugin * plugin)
899 g_return_val_if_fail (plugin != NULL, NULL);
901 return g_list_copy (plugin->features);
906 * @name: name of plugin to load
908 * Load the named plugin.
910 * Returns: whether the plugin was loaded or not
913 gst_plugin_load (const gchar * name)
916 GError *error = NULL;
918 plugin = gst_registry_pool_find_plugin (name);
920 plugin = gst_plugin_load_file (plugin->filename, &error);
922 GST_WARNING ("load_plugin error: %s\n", error->message);
923 g_error_free (error);
929 GST_DEBUG ("Could not find %s in registry pool", name);