1 /*****************************************************************************
2 * events.c: events interface
3 * This library provides an interface to the send and receive events.
4 * It is more lightweight than variable based callback.
5 *****************************************************************************
6 * Copyright (C) 1998-2005 the VideoLAN team
9 * Authors: Pierre d'Herbemont <pdherbemont # videolan.org >
11 * This program is free software; you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License as published by
13 * the Free Software Foundation; either version 2 of the License, or
14 * (at your option) any later version.
16 * This program is distributed in the hope that it will be useful,
17 * but WITHOUT ANY WARRANTY; without even the implied warranty of
18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19 * GNU General Public License for more details.
21 * You should have received a copy of the GNU General Public License
22 * along with this program; if not, write to the Free Software
23 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
24 *****************************************************************************/
26 /*****************************************************************************
28 *****************************************************************************/
34 #include <vlc_common.h>
38 #include <vlc_events.h>
39 #include <vlc_arrays.h>
41 /*****************************************************************************
42 * Documentation : Read vlc_events.h
43 *****************************************************************************/
47 /*****************************************************************************
49 *****************************************************************************/
51 typedef struct vlc_event_listener_t
54 vlc_event_callback_t pf_callback;
56 char * psz_debug_name;
58 } vlc_event_listener_t;
60 typedef struct vlc_event_listeners_group_t
62 vlc_event_type_t event_type;
63 DECL_ARRAY(struct vlc_event_listener_t *) listeners;
65 /* Used in vlc_event_send() to make sure to behave
66 Correctly when vlc_event_detach was called during
68 bool b_sublistener_removed;
70 } vlc_event_listeners_group_t;
73 static const char ppsz_event_type_to_name[][33] =
75 [vlc_InputStateChanged] = "vlc_InputStateChanged",
77 [vlc_InputItemMetaChanged] = "vlc_InputItemMetaChanged",
78 [vlc_InputItemSubItemAdded] = "vlc_InputItemSubItemAdded",
79 [vlc_InputItemDurationChanged] = "vlc_InputItemDurationChanged",
80 [vlc_InputItemPreparsedChanged] = "vlc_InputItemPreparsedChanged",
82 [vlc_ServicesDiscoveryItemAdded] = "vlc_ServicesDiscoveryItemAdded",
83 [vlc_ServicesDiscoveryItemRemoved] = "vlc_ServicesDiscoveryItemRemoved"
84 [vlc_ServicesDiscoveryStarted] = "vlc_ServicesDiscoveryStarted"
85 [vlc_ServicesDiscoveryEnded] = "vlc_ServicesDiscoveryEnded"
90 listeners_are_equal( vlc_event_listener_t * listener1,
91 vlc_event_listener_t * listener2 )
93 return listener1->pf_callback == listener2->pf_callback &&
94 listener1->p_user_data == listener2->p_user_data;
98 group_contains_listener( vlc_event_listeners_group_t * group,
99 vlc_event_listener_t * searched_listener )
101 vlc_event_listener_t * listener;
102 FOREACH_ARRAY( listener, group->listeners )
103 if( listeners_are_equal(searched_listener, listener) )
109 /*****************************************************************************
111 *****************************************************************************/
114 * Initialize event manager object
115 * p_obj is the object that contains the event manager. But not
116 * necessarily a vlc_object_t (an input_item_t is not a vlc_object_t
118 * p_parent_obj gives a libvlc instance
120 int __vlc_event_manager_init( vlc_event_manager_t * p_em, void * p_obj,
121 vlc_object_t * p_parent_obj )
124 p_em->p_parent_object = p_parent_obj;
125 vlc_mutex_init( &p_em->object_lock );
127 /* We need a recursive lock here, because we need to be able
128 * to call libvlc_event_detach even if vlc_event_send is in
130 * This ensures that after libvlc_event_detach, the callback
131 * will never gets triggered.
133 vlc_mutex_init_recursive( &p_em->event_sending_lock );
134 ARRAY_INIT( p_em->listeners_groups );
139 * Destroy the event manager
141 void vlc_event_manager_fini( vlc_event_manager_t * p_em )
143 struct vlc_event_listeners_group_t * listeners_group;
144 struct vlc_event_listener_t * listener;
146 vlc_mutex_destroy( &p_em->object_lock );
147 vlc_mutex_destroy( &p_em->event_sending_lock );
149 FOREACH_ARRAY( listeners_group, p_em->listeners_groups )
150 FOREACH_ARRAY( listener, listeners_group->listeners )
153 ARRAY_RESET( listeners_group->listeners );
154 free( listeners_group );
156 ARRAY_RESET( p_em->listeners_groups );
160 * Destroy the event manager
162 int vlc_event_manager_register_event_type(
163 vlc_event_manager_t * p_em,
164 vlc_event_type_t event_type )
166 vlc_event_listeners_group_t * listeners_group;
167 listeners_group = malloc(sizeof(vlc_event_listeners_group_t));
169 if( !listeners_group )
172 listeners_group->event_type = event_type;
173 ARRAY_INIT( listeners_group->listeners );
175 vlc_mutex_lock( &p_em->object_lock );
176 ARRAY_APPEND( p_em->listeners_groups, listeners_group );
177 vlc_mutex_unlock( &p_em->object_lock );
183 * Send an event to the listener attached to this p_em.
185 void vlc_event_send( vlc_event_manager_t * p_em,
186 vlc_event_t * p_event )
188 vlc_event_listeners_group_t * listeners_group = NULL;
189 vlc_event_listener_t * listener;
190 vlc_event_listener_t * array_of_cached_listeners = NULL;
191 vlc_event_listener_t * cached_listener;
192 int i, i_cached_listeners = 0;
194 /* Fill event with the sending object now */
195 p_event->p_obj = p_em->p_obj;
197 vlc_mutex_lock( &p_em->object_lock );
198 FOREACH_ARRAY( listeners_group, p_em->listeners_groups )
199 if( listeners_group->event_type == p_event->type )
201 if( listeners_group->listeners.i_size <= 0 )
204 /* Save the function to call */
205 i_cached_listeners = listeners_group->listeners.i_size;
206 array_of_cached_listeners = malloc(
207 sizeof(vlc_event_listener_t)*i_cached_listeners );
208 if( !array_of_cached_listeners )
210 msg_Err( p_em->p_parent_object, "Not enough memory in vlc_event_send" );
211 vlc_mutex_unlock( &p_em->object_lock );
215 cached_listener = array_of_cached_listeners;
216 FOREACH_ARRAY( listener, listeners_group->listeners )
217 memcpy( cached_listener, listener, sizeof(vlc_event_listener_t));
219 cached_listener->psz_debug_name = strdup(cached_listener->psz_debug_name);
227 vlc_mutex_unlock( &p_em->object_lock );
229 /* Call the function attached */
230 cached_listener = array_of_cached_listeners;
232 if( !listeners_group || !array_of_cached_listeners )
234 free( array_of_cached_listeners );
238 vlc_mutex_lock( &p_em->event_sending_lock ) ;
240 /* Track item removed from *this* thread, with a simple flag */
241 listeners_group->b_sublistener_removed = false;
243 for( i = 0; i < i_cached_listeners; i++ )
246 msg_Dbg( p_em->p_parent_object,
247 "Calling '%s' with a '%s' event (data %p)",
248 cached_listener->psz_debug_name,
249 ppsz_event_type_to_name[p_event->type],
250 cached_listener->p_user_data );
251 free(cached_listener->psz_debug_name);
253 /* No need to lock on listeners_group, a listener group can't be removed */
254 if( listeners_group->b_sublistener_removed )
256 /* If a callback was removed, this gets called */
258 vlc_mutex_lock( &p_em->object_lock );
259 valid_listener = group_contains_listener( listeners_group, cached_listener );
260 vlc_mutex_unlock( &p_em->object_lock );
261 if( !valid_listener )
264 msg_Dbg( p_em->p_parent_object, "Callback was removed during execution" );
270 cached_listener->pf_callback( p_event, cached_listener->p_user_data );
273 vlc_mutex_unlock( &p_em->event_sending_lock );
275 free( array_of_cached_listeners );
279 * Add a callback for an event.
281 int __vlc_event_attach( vlc_event_manager_t * p_em,
282 vlc_event_type_t event_type,
283 vlc_event_callback_t pf_callback,
285 const char * psz_debug_name )
287 vlc_event_listeners_group_t * listeners_group;
288 vlc_event_listener_t * listener;
289 listener = malloc(sizeof(vlc_event_listener_t));
293 listener->p_user_data = p_user_data;
294 listener->pf_callback = pf_callback;
296 listener->psz_debug_name = strdup( psz_debug_name );
298 (void)psz_debug_name;
301 vlc_mutex_lock( &p_em->object_lock );
302 FOREACH_ARRAY( listeners_group, p_em->listeners_groups )
303 if( listeners_group->event_type == event_type )
305 ARRAY_APPEND( listeners_group->listeners, listener );
307 msg_Dbg( p_em->p_parent_object,
308 "Listening to '%s' event with '%s' (data %p)",
309 ppsz_event_type_to_name[event_type],
310 listener->psz_debug_name,
311 listener->p_user_data );
313 vlc_mutex_unlock( &p_em->object_lock );
317 vlc_mutex_unlock( &p_em->object_lock );
319 msg_Err( p_em->p_parent_object, "Can't attach to an object event manager event" );
325 * Remove a callback for an event.
328 int vlc_event_detach( vlc_event_manager_t *p_em,
329 vlc_event_type_t event_type,
330 vlc_event_callback_t pf_callback,
333 vlc_event_listeners_group_t * listeners_group;
334 struct vlc_event_listener_t * listener;
336 vlc_mutex_lock( &p_em->object_lock );
337 vlc_mutex_lock( &p_em->event_sending_lock );
338 FOREACH_ARRAY( listeners_group, p_em->listeners_groups )
339 if( listeners_group->event_type == event_type )
341 FOREACH_ARRAY( listener, listeners_group->listeners )
342 if( listener->pf_callback == pf_callback &&
343 listener->p_user_data == p_user_data )
345 /* Tell vlc_event_send, we did remove an item from that group,
346 in case vlc_event_send is in our caller stack */
347 listeners_group->b_sublistener_removed = true;
349 /* that's our listener */
350 ARRAY_REMOVE( listeners_group->listeners,
351 fe_idx /* This comes from the macro (and that's why
354 msg_Dbg( p_em->p_parent_object,
355 "Detaching '%s' from '%s' event (data %p)",
356 listener->psz_debug_name,
357 ppsz_event_type_to_name[event_type],
358 listener->p_user_data );
360 free( listener->psz_debug_name );
363 vlc_mutex_unlock( &p_em->event_sending_lock );
364 vlc_mutex_unlock( &p_em->object_lock );
370 vlc_mutex_unlock( &p_em->event_sending_lock );
371 vlc_mutex_unlock( &p_em->object_lock );
373 msg_Warn( p_em->p_parent_object, "Can't detach to an object event manager event" );