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 VLC authors and VideoLAN
9 * Authors: Pierre d'Herbemont <pdherbemont # videolan.org >
11 * This program is free software; you can redistribute it and/or modify it
12 * under the terms of the GNU Lesser General Public License as published by
13 * the Free Software Foundation; either version 2.1 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 Lesser General Public License for more details.
21 * You should have received a copy of the GNU Lesser General Public License
22 * along with this program; if not, write to the Free Software Foundation,
23 * 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 *****************************************************************************/
45 /*****************************************************************************
47 *****************************************************************************/
49 typedef struct vlc_event_listener_t
52 vlc_event_callback_t pf_callback
;
53 } vlc_event_listener_t
;
55 typedef struct vlc_event_listeners_group_t
57 vlc_event_type_t event_type
;
58 DECL_ARRAY(struct vlc_event_listener_t
*) listeners
;
60 /* Used in vlc_event_send() to make sure to behave
61 Correctly when vlc_event_detach was called during
63 bool b_sublistener_removed
;
65 } vlc_event_listeners_group_t
;
68 listeners_are_equal( vlc_event_listener_t
* listener1
,
69 vlc_event_listener_t
* listener2
)
71 return listener1
->pf_callback
== listener2
->pf_callback
&&
72 listener1
->p_user_data
== listener2
->p_user_data
;
76 group_contains_listener( vlc_event_listeners_group_t
* group
,
77 vlc_event_listener_t
* searched_listener
)
79 vlc_event_listener_t
* listener
;
80 FOREACH_ARRAY( listener
, group
->listeners
)
81 if( listeners_are_equal(searched_listener
, listener
) )
87 /*****************************************************************************
89 *****************************************************************************/
91 #undef vlc_event_manager_init
93 * Initialize event manager object
94 * p_obj is the object that contains the event manager. But not
95 * necessarily a vlc_object_t (an input_item_t is not a vlc_object_t
98 int vlc_event_manager_init( vlc_event_manager_t
* p_em
, void * p_obj
)
101 vlc_mutex_init( &p_em
->object_lock
);
103 /* We need a recursive lock here, because we need to be able
104 * to call libvlc_event_detach even if vlc_event_send is in
106 * This ensures that after libvlc_event_detach, the callback
107 * will never gets triggered.
109 vlc_mutex_init_recursive( &p_em
->event_sending_lock
);
110 ARRAY_INIT( p_em
->listeners_groups
);
115 * Destroy the event manager
117 void vlc_event_manager_fini( vlc_event_manager_t
* p_em
)
119 struct vlc_event_listeners_group_t
* listeners_group
;
120 struct vlc_event_listener_t
* listener
;
122 vlc_mutex_destroy( &p_em
->object_lock
);
123 vlc_mutex_destroy( &p_em
->event_sending_lock
);
125 FOREACH_ARRAY( listeners_group
, p_em
->listeners_groups
)
126 FOREACH_ARRAY( listener
, listeners_group
->listeners
)
129 ARRAY_RESET( listeners_group
->listeners
);
130 free( listeners_group
);
132 ARRAY_RESET( p_em
->listeners_groups
);
136 * Register the event manager
138 int vlc_event_manager_register_event_type(
139 vlc_event_manager_t
* p_em
,
140 vlc_event_type_t event_type
)
142 vlc_event_listeners_group_t
* listeners_group
;
143 listeners_group
= malloc(sizeof(vlc_event_listeners_group_t
));
145 if( !listeners_group
)
148 listeners_group
->event_type
= event_type
;
149 ARRAY_INIT( listeners_group
->listeners
);
151 vlc_mutex_lock( &p_em
->object_lock
);
152 ARRAY_APPEND( p_em
->listeners_groups
, listeners_group
);
153 vlc_mutex_unlock( &p_em
->object_lock
);
159 * Send an event to the listener attached to this p_em.
161 void vlc_event_send( vlc_event_manager_t
* p_em
,
162 vlc_event_t
* p_event
)
164 vlc_event_listeners_group_t
* listeners_group
= NULL
;
165 vlc_event_listener_t
* listener
;
166 vlc_event_listener_t
* array_of_cached_listeners
= NULL
;
167 vlc_event_listener_t
* cached_listener
;
168 int i
, i_cached_listeners
= 0;
170 /* Fill event with the sending object now */
171 p_event
->p_obj
= p_em
->p_obj
;
173 vlc_mutex_lock( &p_em
->event_sending_lock
) ;
174 vlc_mutex_lock( &p_em
->object_lock
);
176 FOREACH_ARRAY( listeners_group
, p_em
->listeners_groups
)
177 if( listeners_group
->event_type
== p_event
->type
)
179 if( listeners_group
->listeners
.i_size
<= 0 )
182 /* Save the function to call */
183 i_cached_listeners
= listeners_group
->listeners
.i_size
;
184 array_of_cached_listeners
= malloc(
185 sizeof(vlc_event_listener_t
)*i_cached_listeners
);
186 if( !array_of_cached_listeners
)
188 vlc_mutex_unlock( &p_em
->object_lock
);
189 vlc_mutex_unlock( &p_em
->event_sending_lock
) ;
193 cached_listener
= array_of_cached_listeners
;
194 FOREACH_ARRAY( listener
, listeners_group
->listeners
)
195 memcpy( cached_listener
, listener
, sizeof(vlc_event_listener_t
));
203 /* Track item removed from *this* thread, with a simple flag. Indeed
204 * event_sending_lock is a recursive lock. This has the advantage of
205 * allowing to remove an event listener from within a callback */
206 listeners_group
->b_sublistener_removed
= false;
208 vlc_mutex_unlock( &p_em
->object_lock
);
210 /* Call the function attached */
211 cached_listener
= array_of_cached_listeners
;
213 if( !listeners_group
|| !array_of_cached_listeners
)
215 free( array_of_cached_listeners
);
216 vlc_mutex_unlock( &p_em
->event_sending_lock
);
221 for( i
= 0; i
< i_cached_listeners
; i
++ )
223 if( listeners_group
->b_sublistener_removed
)
225 /* If a callback was removed inside one of our callback, this gets
228 vlc_mutex_lock( &p_em
->object_lock
);
229 valid_listener
= group_contains_listener( listeners_group
, cached_listener
);
230 vlc_mutex_unlock( &p_em
->object_lock
);
231 if( !valid_listener
)
237 cached_listener
->pf_callback( p_event
, cached_listener
->p_user_data
);
240 vlc_mutex_unlock( &p_em
->event_sending_lock
);
242 free( array_of_cached_listeners
);
245 #undef vlc_event_attach
247 * Add a callback for an event.
249 int vlc_event_attach( vlc_event_manager_t
* p_em
,
250 vlc_event_type_t event_type
,
251 vlc_event_callback_t pf_callback
,
254 vlc_event_listeners_group_t
* listeners_group
;
255 vlc_event_listener_t
* listener
;
256 listener
= malloc(sizeof(vlc_event_listener_t
));
260 listener
->p_user_data
= p_user_data
;
261 listener
->pf_callback
= pf_callback
;
263 vlc_mutex_lock( &p_em
->object_lock
);
264 FOREACH_ARRAY( listeners_group
, p_em
->listeners_groups
)
265 if( listeners_group
->event_type
== event_type
)
267 ARRAY_APPEND( listeners_group
->listeners
, listener
);
268 vlc_mutex_unlock( &p_em
->object_lock
);
272 /* Unknown event = BUG */
277 * Remove a callback for an event.
280 void vlc_event_detach( vlc_event_manager_t
*p_em
,
281 vlc_event_type_t event_type
,
282 vlc_event_callback_t pf_callback
,
285 vlc_event_listeners_group_t
* listeners_group
;
286 struct vlc_event_listener_t
* listener
;
288 vlc_mutex_lock( &p_em
->event_sending_lock
);
289 vlc_mutex_lock( &p_em
->object_lock
);
290 FOREACH_ARRAY( listeners_group
, p_em
->listeners_groups
)
291 if( listeners_group
->event_type
== event_type
)
293 FOREACH_ARRAY( listener
, listeners_group
->listeners
)
294 if( listener
->pf_callback
== pf_callback
&&
295 listener
->p_user_data
== p_user_data
)
297 /* Tell vlc_event_send, we did remove an item from that group,
298 in case vlc_event_send is in our caller stack */
299 listeners_group
->b_sublistener_removed
= true;
301 /* that's our listener */
302 ARRAY_REMOVE( listeners_group
->listeners
,
303 fe_idx
/* This comes from the macro (and that's why
306 vlc_mutex_unlock( &p_em
->event_sending_lock
);
307 vlc_mutex_unlock( &p_em
->object_lock
);