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);
208 GST_LOG ("plugin \"%s\" looks good", GST_STR_NULL (plugin->filename));
210 gst_plugin_desc_copy (&plugin->desc, desc);
211 plugin->module = module;
213 if (!((desc->plugin_init) (plugin))) {
215 GST_INFO ("plugin \"%s\" failed to initialise", plugin->filename);
216 plugin->module = NULL;
221 GST_LOG ("plugin \"%s\" initialised", GST_STR_NULL (plugin->filename));
228 * _gst_plugin_fault_handler_restore:
229 * segfault handler restorer
232 _gst_plugin_fault_handler_restore (void)
234 struct sigaction action;
236 memset (&action, 0, sizeof (action));
237 action.sa_handler = SIG_DFL;
239 sigaction (SIGSEGV, &action, NULL);
243 * _gst_plugin_fault_handler_sighandler:
244 * segfault handler implementation
247 _gst_plugin_fault_handler_sighandler (int signum)
249 /* We need to restore the fault handler or we'll keep getting it */
250 _gst_plugin_fault_handler_restore ();
254 g_print ("\nERROR: ");
255 g_print ("Caught a segmentation fault while loading plugin file:\n");
256 g_print ("%s\n\n", _gst_plugin_fault_handler_filename);
257 g_print ("Please either:\n");
258 g_print ("- remove it and restart.\n");
259 g_print ("- run with --gst-disable-segtrap and debug.\n");
263 g_print ("Caught unhandled signal on plugin loading\n");
269 * _gst_plugin_fault_handler_setup:
270 * sets up the segfault handler
273 _gst_plugin_fault_handler_setup (void)
275 struct sigaction action;
277 /* if asked to leave segfaults alone, just return */
278 if (_gst_disable_segtrap)
281 if (_gst_plugin_fault_handler_is_setup)
284 memset (&action, 0, sizeof (action));
285 action.sa_handler = _gst_plugin_fault_handler_sighandler;
287 sigaction (SIGSEGV, &action, NULL);
291 _gst_plugin_fault_handler_restore (void)
296 _gst_plugin_fault_handler_setup (void)
301 static void _gst_plugin_fault_handler_setup ();
304 * gst_plugin_check_module:
305 * @module: GModule handle to check for pluginness
306 * @error: pointer to a NULL-valued GError
307 * @pptr: pointer to a gpointer used to return the gst_plugin_desc symbol
310 * Checks if the given module is a GStreamer plugin
312 * Returns: TRUE if the given module is a GStreamer plugin
315 gst_plugin_check_module (GModule * module, const char *filename,
316 GError ** error, gpointer * pptr)
323 if (module == NULL) {
324 GST_DEBUG ("Error loading plugin %s, reason: %s", filename,
326 g_set_error (error, GST_PLUGIN_ERROR, GST_PLUGIN_ERROR_MODULE,
327 "Error loading plugin %s, reason: %s", filename, g_module_error ());
331 if (!g_module_symbol (module, "gst_plugin_desc", pptr)) {
332 GST_DEBUG ("Could not find plugin entry point in \"%s\"", filename);
335 GST_PLUGIN_ERROR_MODULE,
336 "Could not find plugin entry point in \"%s\"", filename);
344 * gst_plugin_check_file:
345 * @filename: the plugin filename to check for pluginness
346 * @error: pointer to a NULL-valued GError
348 * Checks if the given path represents a GStreamer plugin.
350 * Returns: TRUE if the given path is a GStreamer plugin.
353 gst_plugin_check_file (const gchar * filename, GError ** error)
356 struct stat file_status;
359 g_return_val_if_fail (filename != NULL, FALSE);
361 if (g_module_supported () == FALSE) {
364 GST_PLUGIN_ERROR_MODULE, "Dynamic loading not supported");
368 if (stat (filename, &file_status)) {
371 GST_PLUGIN_ERROR_MODULE, "Problem accessing file %s: %s\n", filename,
376 module = g_module_open (filename, G_MODULE_BIND_LAZY | G_MODULE_BIND_LOCAL);
377 check = gst_plugin_check_module (module, filename, error, NULL);
378 g_module_close (module);
380 GST_INFO ("file \"%s\" %s look like a gst plugin", filename,
381 check ? "does" : "doesn't");
387 * gst_plugin_load_file:
388 * @filename: the plugin filename to load
389 * @error: pointer to a NULL-valued GError
391 * Loads the given plugin.
393 * Returns: a new GstPlugin or NULL, if an error occurred.
396 gst_plugin_load_file (const gchar * filename, GError ** error)
401 gboolean free_plugin;
404 g_return_val_if_fail (filename != NULL, NULL);
406 GST_CAT_DEBUG (GST_CAT_PLUGIN_LOADING, "attempt to load plugin \"%s\"",
409 module = g_module_open (filename, G_MODULE_BIND_LAZY | G_MODULE_BIND_LOCAL);
411 /* handle module == NULL case */
412 if (!gst_plugin_check_module (module, filename, error, &ptr))
415 desc = (GstPluginDesc *) ptr;
417 plugin = gst_registry_pool_find_plugin (desc->name);
420 plugin = g_new0 (GstPlugin, 1);
421 plugin->filename = g_strdup (filename);
422 GST_DEBUG ("created new GstPlugin %p for file \"%s\"", plugin, filename);
425 if (gst_plugin_is_loaded (plugin)) {
426 g_module_close (module);
427 if (plugin->filename && strcmp (plugin->filename, filename) != 0) {
429 ("plugin %p from file \"%s\" with same name %s is already "
430 "loaded, aborting loading of \"%s\"", plugin, plugin->filename,
431 plugin->desc.name, filename);
432 g_set_error (error, GST_PLUGIN_ERROR,
433 GST_PLUGIN_ERROR_NAME_MISMATCH,
434 "plugin %p from file \"%s\" with same name %s is already "
435 "loaded, aborting loading of \"%s\"", plugin, plugin->filename,
436 plugin->desc.name, filename);
441 GST_LOG ("Plugin %p for file \"%s\" already loaded, returning it now",
446 GST_LOG ("Plugin %p for file \"%s\" prepared, calling entry function...",
449 if (g_module_symbol (module, "plugin_init", &ptr)) {
451 ("plugin %p from file \"%s\" exports a symbol named plugin_init\n",
452 plugin, plugin->filename);
453 g_set_error (error, GST_PLUGIN_ERROR, GST_PLUGIN_ERROR_NAME_MISMATCH,
454 "plugin \"%s\" exports a symbol named plugin_init", desc->name);
457 /* this is where we load the actual .so, so let's trap SIGSEGV */
458 _gst_plugin_fault_handler_setup ();
459 _gst_plugin_fault_handler_filename = plugin->filename;
461 GST_LOG ("Plugin %p for file \"%s\" prepared, registering...",
464 if (gst_plugin_register_func (plugin, module, desc)) {
465 /* remove signal handler */
466 _gst_plugin_fault_handler_restore ();
467 _gst_plugin_fault_handler_filename = NULL;
468 GST_INFO ("plugin \"%s\" loaded", plugin->filename);
471 /* remove signal handler */
472 _gst_plugin_fault_handler_restore ();
473 GST_DEBUG ("gst_plugin_register_func failed for plugin \"%s\"", filename);
477 GST_PLUGIN_ERROR_MODULE,
478 "gst_plugin_register_func failed for plugin \"%s\"", filename);
479 g_module_close (module);
487 gst_plugin_desc_copy (GstPluginDesc * dest, const GstPluginDesc * src)
489 dest->major_version = src->major_version;
490 dest->minor_version = src->minor_version;
492 dest->name = g_strdup (src->name);
493 g_free (dest->description);
494 dest->description = g_strdup (src->description);
495 dest->plugin_init = src->plugin_init;
496 dest->plugin_exit = src->plugin_exit;
497 g_free (dest->version);
498 dest->version = g_strdup (src->version);
499 g_free (dest->license);
500 dest->license = g_strdup (src->license);
501 g_free (dest->package);
502 dest->package = g_strdup (src->package);
503 g_free (dest->origin);
504 dest->origin = g_strdup (src->origin);
510 gst_plugin_desc_free (GstPluginDesc * desc)
513 g_free (desc->description);
514 g_free (desc->version);
515 g_free (desc->license);
516 g_free (desc->package);
517 g_free (desc->origin);
519 memset (desc, 0, sizeof (GstPluginDesc));
523 * gst_plugin_unload_plugin:
524 * @plugin: The plugin to unload
526 * Unload the given plugin.
528 * Returns: whether or not the plugin unloaded
531 gst_plugin_unload_plugin (GstPlugin * plugin)
533 g_return_val_if_fail (plugin != NULL, FALSE);
538 if (g_module_close (plugin->module)) {
539 plugin->module = NULL;
540 GST_CAT_INFO (GST_CAT_PLUGIN_LOADING, "plugin \"%s\" unloaded",
544 GST_CAT_INFO (GST_CAT_PLUGIN_LOADING, "failed to unload plugin \"%s\"",
551 * gst_plugin_get_name:
552 * @plugin: plugin to get the name of
554 * Get the short name of the plugin
556 * Returns: the name of the plugin
559 gst_plugin_get_name (GstPlugin * plugin)
561 g_return_val_if_fail (plugin != NULL, NULL);
563 return plugin->desc.name;
567 * gst_plugin_get_description:
568 * @plugin: plugin to get long name of
570 * Get the long descriptive name of the plugin
572 * Returns: the long name of the plugin
574 G_CONST_RETURN gchar *
575 gst_plugin_get_description (GstPlugin * plugin)
577 g_return_val_if_fail (plugin != NULL, NULL);
579 return plugin->desc.description;
583 * gst_plugin_get_filename:
584 * @plugin: plugin to get the filename of
586 * get the filename of the plugin
588 * Returns: the filename of the plugin
590 G_CONST_RETURN gchar *
591 gst_plugin_get_filename (GstPlugin * plugin)
593 g_return_val_if_fail (plugin != NULL, NULL);
595 return plugin->filename;
599 * gst_plugin_get_version:
600 * @plugin: plugin to get the version of
602 * get the version of the plugin
604 * Returns: the version of the plugin
606 G_CONST_RETURN gchar *
607 gst_plugin_get_version (GstPlugin * plugin)
609 g_return_val_if_fail (plugin != NULL, NULL);
611 return plugin->desc.version;
615 * gst_plugin_get_license:
616 * @plugin: plugin to get the license of
618 * get the license of the plugin
620 * Returns: the license of the plugin
622 G_CONST_RETURN gchar *
623 gst_plugin_get_license (GstPlugin * plugin)
625 g_return_val_if_fail (plugin != NULL, NULL);
627 return plugin->desc.license;
631 * gst_plugin_get_package:
632 * @plugin: plugin to get the package of
634 * get the package the plugin belongs to.
636 * Returns: the package of the plugin
638 G_CONST_RETURN gchar *
639 gst_plugin_get_package (GstPlugin * plugin)
641 g_return_val_if_fail (plugin != NULL, NULL);
643 return plugin->desc.package;
647 * gst_plugin_get_origin:
648 * @plugin: plugin to get the origin of
650 * get the URL where the plugin comes from
652 * Returns: the origin of the plugin
654 G_CONST_RETURN gchar *
655 gst_plugin_get_origin (GstPlugin * plugin)
657 g_return_val_if_fail (plugin != NULL, NULL);
659 return plugin->desc.origin;
663 * gst_plugin_get_module:
664 * @plugin: plugin to query
666 * Gets the #GModule of the plugin. If the plugin isn't loaded yet, NULL is
669 * Returns: module belonging to the plugin or NULL if the plugin isn't
673 gst_plugin_get_module (GstPlugin * plugin)
675 g_return_val_if_fail (plugin != NULL, NULL);
677 return plugin->module;
681 * gst_plugin_is_loaded:
682 * @plugin: plugin to query
684 * queries if the plugin is loaded into memory
686 * Returns: TRUE is loaded, FALSE otherwise
689 gst_plugin_is_loaded (GstPlugin * plugin)
691 g_return_val_if_fail (plugin != NULL, FALSE);
693 return (plugin->module != NULL);
697 * gst_plugin_feature_list:
698 * @plugin: plugin to query
699 * @filter: the filter to use
700 * @first: only return first match
701 * @user_data: user data passed to the filter function
703 * Runs a filter against all plugin features and returns a GList with
704 * the results. If the first flag is set, only the first match is
705 * returned (as a list with a single object).
707 * Returns: a GList of features, g_list_free after use.
710 gst_plugin_feature_filter (GstPlugin * plugin,
711 GstPluginFeatureFilter filter, gboolean first, gpointer user_data)
713 return gst_filter_run (plugin->features, (GstFilterFunc) filter, first,
719 GstPluginFeatureFilter filter;
727 _feature_filter (GstPlugin * plugin, gpointer user_data)
730 FeatureFilterData *data = (FeatureFilterData *) user_data;
733 gst_plugin_feature_filter (plugin, data->filter, data->first,
736 data->result = g_list_concat (data->result, result);
743 * gst_plugin_list_feature_list:
744 * @list: a list of plugins to query
745 * @filter: the filter to use
746 * @first: only return first match
747 * @user_data: user data passed to the filter function
749 * Runs a filter against all plugin features of the plugins in the given
750 * list and returns a GList with the results.
751 * If the first flag is set, only the first match is
752 * returned (as a list with a single object).
754 * Returns: a GList of features, g_list_free after use.
757 gst_plugin_list_feature_filter (GList * list,
758 GstPluginFeatureFilter filter, gboolean first, gpointer user_data)
760 FeatureFilterData data;
763 data.filter = filter;
765 data.user_data = user_data;
768 result = gst_filter_run (list, (GstFilterFunc) _feature_filter, first, &data);
769 g_list_free (result);
775 * gst_plugin_name_filter:
776 * @plugin: the plugin to check
777 * @name: the name of the plugin
779 * A standard filter that returns TRUE when the plugin is of the
782 * Returns: TRUE if the plugin is of the given name.
785 gst_plugin_name_filter (GstPlugin * plugin, const gchar * name)
787 return (plugin->desc.name && !strcmp (plugin->desc.name, name));
791 * gst_plugin_find_feature:
792 * @plugin: plugin to get the feature from
793 * @name: The name of the feature to find
794 * @type: The type of the feature to find
796 * Find a feature of the given name and type in the given plugin.
798 * Returns: a GstPluginFeature or NULL if the feature was not found.
801 gst_plugin_find_feature (GstPlugin * plugin, const gchar * name, GType type)
804 GstPluginFeature *result = NULL;
805 GstTypeNameData data;
807 g_return_val_if_fail (name != NULL, NULL);
812 walk = gst_filter_run (plugin->features,
813 (GstFilterFunc) gst_plugin_feature_type_name_filter, TRUE, &data);
816 result = GST_PLUGIN_FEATURE (walk->data);
822 * gst_plugin_add_feature:
823 * @plugin: plugin to add feature to
824 * @feature: feature to add
826 * Add feature to the list of those provided by the plugin.
827 * There is a separate namespace for each plugin feature type.
828 * See #gst_plugin_get_feature_list
831 gst_plugin_add_feature (GstPlugin * plugin, GstPluginFeature * feature)
833 GstPluginFeature *oldfeature;
835 /* FIXME 0.9: get reference counting somewhat right in here,
836 * GstPluginFeatures should probably be GstObjects that are sinked when
837 * adding them to a plugin */
838 g_return_if_fail (plugin != NULL);
839 g_return_if_fail (GST_IS_PLUGIN_FEATURE (feature));
840 g_return_if_fail (feature != NULL);
842 oldfeature = gst_plugin_find_feature (plugin,
843 GST_PLUGIN_FEATURE_NAME (feature), G_OBJECT_TYPE (feature));
845 if (oldfeature == feature) {
846 GST_WARNING ("feature %s has already been added",
847 GST_PLUGIN_FEATURE_NAME (feature));
848 /* g_object_unref (feature); */
849 } else if (oldfeature) {
850 GST_WARNING ("feature %s already present in plugin",
851 GST_PLUGIN_FEATURE_NAME (feature));
852 /* g_object_unref (feature); */
854 feature->manager = plugin;
855 plugin->features = g_list_prepend (plugin->features, feature);
856 plugin->numfeatures++;
861 * gst_plugin_get_feature_list:
862 * @plugin: the plugin to get the features from
864 * get a list of all the features that this plugin provides
866 * Returns: a GList of features, use g_list_free to free the list.
869 gst_plugin_get_feature_list (GstPlugin * plugin)
871 g_return_val_if_fail (plugin != NULL, NULL);
873 return g_list_copy (plugin->features);
878 * @name: name of plugin to load
880 * Load the named plugin.
882 * Returns: whether the plugin was loaded or not
885 gst_plugin_load (const gchar * name)
888 GError *error = NULL;
890 plugin = gst_registry_pool_find_plugin (name);
892 plugin = gst_plugin_load_file (plugin->filename, &error);
894 GST_WARNING ("load_plugin error: %s\n", error->message);
895 g_error_free (error);
901 GST_DEBUG ("Could not find %s in registry pool", name);