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",
81 [vlc_InputItemNameChanged] = "vlc_InputItemNameChanged",
82 [vlc_InputItemInfoChanged] = "vlc_InputItemInfoChanged",
84 [vlc_ServicesDiscoveryItemAdded] = "vlc_ServicesDiscoveryItemAdded",
85 [vlc_ServicesDiscoveryItemRemoved] = "vlc_ServicesDiscoveryItemRemoved"
86 [vlc_ServicesDiscoveryStarted] = "vlc_ServicesDiscoveryStarted"
87 [vlc_ServicesDiscoveryEnded] = "vlc_ServicesDiscoveryEnded"
92 listeners_are_equal( vlc_event_listener_t * listener1,
93 vlc_event_listener_t * listener2 )
95 return listener1->pf_callback == listener2->pf_callback &&
96 listener1->p_user_data == listener2->p_user_data;
100 group_contains_listener( vlc_event_listeners_group_t * group,
101 vlc_event_listener_t * searched_listener )
103 vlc_event_listener_t * listener;
104 FOREACH_ARRAY( listener, group->listeners )
105 if( listeners_are_equal(searched_listener, listener) )
111 /*****************************************************************************
113 *****************************************************************************/
116 * Initialize event manager object
117 * p_obj is the object that contains the event manager. But not
118 * necessarily a vlc_object_t (an input_item_t is not a vlc_object_t
120 * p_parent_obj gives a libvlc instance
122 int __vlc_event_manager_init( vlc_event_manager_t * p_em, void * p_obj,
123 vlc_object_t * p_parent_obj )
126 p_em->p_parent_object = p_parent_obj;
127 vlc_mutex_init( &p_em->object_lock );
129 /* We need a recursive lock here, because we need to be able
130 * to call libvlc_event_detach even if vlc_event_send is in
132 * This ensures that after libvlc_event_detach, the callback
133 * will never gets triggered.
135 vlc_mutex_init_recursive( &p_em->event_sending_lock );
136 ARRAY_INIT( p_em->listeners_groups );
141 * Destroy the event manager
143 void vlc_event_manager_fini( vlc_event_manager_t * p_em )
145 struct vlc_event_listeners_group_t * listeners_group;
146 struct vlc_event_listener_t * listener;
148 vlc_mutex_destroy( &p_em->object_lock );
149 vlc_mutex_destroy( &p_em->event_sending_lock );
151 FOREACH_ARRAY( listeners_group, p_em->listeners_groups )
152 FOREACH_ARRAY( listener, listeners_group->listeners )
155 ARRAY_RESET( listeners_group->listeners );
156 free( listeners_group );
158 ARRAY_RESET( p_em->listeners_groups );
162 * Destroy the event manager
164 int vlc_event_manager_register_event_type(
165 vlc_event_manager_t * p_em,
166 vlc_event_type_t event_type )
168 vlc_event_listeners_group_t * listeners_group;
169 listeners_group = malloc(sizeof(vlc_event_listeners_group_t));
171 if( !listeners_group )
174 listeners_group->event_type = event_type;
175 ARRAY_INIT( listeners_group->listeners );
177 vlc_mutex_lock( &p_em->object_lock );
178 ARRAY_APPEND( p_em->listeners_groups, listeners_group );
179 vlc_mutex_unlock( &p_em->object_lock );
185 * Send an event to the listener attached to this p_em.
187 void vlc_event_send( vlc_event_manager_t * p_em,
188 vlc_event_t * p_event )
190 vlc_event_listeners_group_t * listeners_group = NULL;
191 vlc_event_listener_t * listener;
192 vlc_event_listener_t * array_of_cached_listeners = NULL;
193 vlc_event_listener_t * cached_listener;
194 int i, i_cached_listeners = 0;
196 /* Fill event with the sending object now */
197 p_event->p_obj = p_em->p_obj;
199 vlc_mutex_lock( &p_em->object_lock );
200 FOREACH_ARRAY( listeners_group, p_em->listeners_groups )
201 if( listeners_group->event_type == p_event->type )
203 if( listeners_group->listeners.i_size <= 0 )
206 /* Save the function to call */
207 i_cached_listeners = listeners_group->listeners.i_size;
208 array_of_cached_listeners = malloc(
209 sizeof(vlc_event_listener_t)*i_cached_listeners );
210 if( !array_of_cached_listeners )
212 msg_Err( p_em->p_parent_object, "Not enough memory in vlc_event_send" );
213 vlc_mutex_unlock( &p_em->object_lock );
217 cached_listener = array_of_cached_listeners;
218 FOREACH_ARRAY( listener, listeners_group->listeners )
219 memcpy( cached_listener, listener, sizeof(vlc_event_listener_t));
221 cached_listener->psz_debug_name = strdup(cached_listener->psz_debug_name);
229 vlc_mutex_unlock( &p_em->object_lock );
231 /* Call the function attached */
232 cached_listener = array_of_cached_listeners;
234 if( !listeners_group || !array_of_cached_listeners )
236 free( array_of_cached_listeners );
240 vlc_mutex_lock( &p_em->event_sending_lock ) ;
242 /* Track item removed from *this* thread, with a simple flag */
243 listeners_group->b_sublistener_removed = false;
245 for( i = 0; i < i_cached_listeners; i++ )
248 msg_Dbg( p_em->p_parent_object,
249 "Calling '%s' with a '%s' event (data %p)",
250 cached_listener->psz_debug_name,
251 ppsz_event_type_to_name[p_event->type],
252 cached_listener->p_user_data );
253 free(cached_listener->psz_debug_name);
255 /* No need to lock on listeners_group, a listener group can't be removed */
256 if( listeners_group->b_sublistener_removed )
258 /* If a callback was removed, this gets called */
260 vlc_mutex_lock( &p_em->object_lock );
261 valid_listener = group_contains_listener( listeners_group, cached_listener );
262 vlc_mutex_unlock( &p_em->object_lock );
263 if( !valid_listener )
266 msg_Dbg( p_em->p_parent_object, "Callback was removed during execution" );
272 cached_listener->pf_callback( p_event, cached_listener->p_user_data );
275 vlc_mutex_unlock( &p_em->event_sending_lock );
277 free( array_of_cached_listeners );
281 * Add a callback for an event.
283 int __vlc_event_attach( vlc_event_manager_t * p_em,
284 vlc_event_type_t event_type,
285 vlc_event_callback_t pf_callback,
287 const char * psz_debug_name )
289 vlc_event_listeners_group_t * listeners_group;
290 vlc_event_listener_t * listener;
291 listener = malloc(sizeof(vlc_event_listener_t));
295 listener->p_user_data = p_user_data;
296 listener->pf_callback = pf_callback;
298 listener->psz_debug_name = strdup( psz_debug_name );
300 (void)psz_debug_name;
303 vlc_mutex_lock( &p_em->object_lock );
304 FOREACH_ARRAY( listeners_group, p_em->listeners_groups )
305 if( listeners_group->event_type == event_type )
307 ARRAY_APPEND( listeners_group->listeners, listener );
309 msg_Dbg( p_em->p_parent_object,
310 "Listening to '%s' event with '%s' (data %p)",
311 ppsz_event_type_to_name[event_type],
312 listener->psz_debug_name,
313 listener->p_user_data );
315 vlc_mutex_unlock( &p_em->object_lock );
319 vlc_mutex_unlock( &p_em->object_lock );
321 msg_Err( p_em->p_parent_object, "Can't attach to an object event manager event" );
327 * Remove a callback for an event.
330 int vlc_event_detach( vlc_event_manager_t *p_em,
331 vlc_event_type_t event_type,
332 vlc_event_callback_t pf_callback,
335 vlc_event_listeners_group_t * listeners_group;
336 struct vlc_event_listener_t * listener;
338 vlc_mutex_lock( &p_em->object_lock );
339 vlc_mutex_lock( &p_em->event_sending_lock );
340 FOREACH_ARRAY( listeners_group, p_em->listeners_groups )
341 if( listeners_group->event_type == event_type )
343 FOREACH_ARRAY( listener, listeners_group->listeners )
344 if( listener->pf_callback == pf_callback &&
345 listener->p_user_data == p_user_data )
347 /* Tell vlc_event_send, we did remove an item from that group,
348 in case vlc_event_send is in our caller stack */
349 listeners_group->b_sublistener_removed = true;
351 /* that's our listener */
352 ARRAY_REMOVE( listeners_group->listeners,
353 fe_idx /* This comes from the macro (and that's why
356 msg_Dbg( p_em->p_parent_object,
357 "Detaching '%s' from '%s' event (data %p)",
358 listener->psz_debug_name,
359 ppsz_event_type_to_name[event_type],
360 listener->p_user_data );
362 free( listener->psz_debug_name );
365 vlc_mutex_unlock( &p_em->event_sending_lock );
366 vlc_mutex_unlock( &p_em->object_lock );
372 vlc_mutex_unlock( &p_em->event_sending_lock );
373 vlc_mutex_unlock( &p_em->object_lock );
375 msg_Warn( p_em->p_parent_object, "Can't detach to an object event manager event" );