1 /*****************************************************************************
2 * event.c: New libvlc event control API
3 *****************************************************************************
4 * Copyright (C) 2007 the VideoLAN team
7 * Authors: Filippo Carone <filippo@carone.org>
8 * Pierre d'Herbemont <pdherbemont # videolan.org>
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License as published by
12 * the Free Software Foundation; either version 2 of the License, or
13 * (at your option) any later version.
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 * GNU General Public License for more details.
20 * You should have received a copy of the GNU General Public License along
21 * with this program; if not, write to the Free Software Foundation, Inc.,
22 * 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
23 *****************************************************************************/
31 #include <vlc/libvlc.h>
33 #include "libvlc_internal.h"
34 #include "event_internal.h"
37 libvlc_event_listener_t listener;
39 struct queue_elmt * next;
42 struct libvlc_event_async_queue {
43 struct queue_elmt *first_elmt, *last_elmt;
48 vlc_cond_t signal_idle;
49 vlc_threadvar_t is_asynch_dispatch_thread_var;
59 static void* event_async_loop(void * arg);
61 static inline struct libvlc_event_async_queue * queue(libvlc_event_manager_t * p_em)
63 return p_em->async_event_queue;
66 static inline bool is_queue_initialized(libvlc_event_manager_t * p_em)
68 return queue(p_em) != NULL;
71 static inline bool current_thread_is_asynch_thread(libvlc_event_manager_t * p_em)
73 return vlc_threadvar_get(queue(p_em)->is_asynch_dispatch_thread_var);
76 /* Lock must be held */
77 static void push(libvlc_event_manager_t * p_em,
78 libvlc_event_listener_t * listener, libvlc_event_t * event)
80 struct queue_elmt * elmt = malloc(sizeof(struct queue_elmt));
81 elmt->listener = *listener;
85 /* Append to the end of the queue */
86 if(!queue(p_em)->first_elmt)
87 queue(p_em)->first_elmt = elmt;
89 queue(p_em)->last_elmt->next = elmt;
90 queue(p_em)->last_elmt = elmt;
93 enum { MaxQueueSize = 300000 };
94 if(queue(p_em)->count++ > MaxQueueSize)
96 fprintf(stderr, "Warning: libvlc event overflow.\n");
102 static inline void queue_lock(libvlc_event_manager_t * p_em)
104 vlc_mutex_lock(&queue(p_em)->lock);
107 static inline void queue_unlock(libvlc_event_manager_t * p_em)
109 vlc_mutex_unlock(&queue(p_em)->lock);
112 /* Lock must be held */
113 static bool pop(libvlc_event_manager_t * p_em,
114 libvlc_event_listener_t * listener, libvlc_event_t * event)
116 if(!queue(p_em)->first_elmt)
117 return false; /* No first_elmt */
119 struct queue_elmt * elmt = queue(p_em)->first_elmt;
120 *listener = elmt->listener;
121 *event = elmt->event;
123 queue(p_em)->first_elmt = elmt->next;
124 if( !elmt->next ) queue(p_em)->last_elmt=NULL;
127 queue(p_em)->count--;
134 /* Lock must be held */
135 static void pop_listener(libvlc_event_manager_t * p_em, libvlc_event_listener_t * listener)
137 struct queue_elmt * iter = queue(p_em)->first_elmt;
138 struct queue_elmt * prev = NULL;
140 if(listeners_are_equal(&iter->listener, listener))
142 struct queue_elmt * to_delete = iter;
144 queue(p_em)->first_elmt = to_delete->next;
146 prev->next = to_delete->next;
147 iter = to_delete->next;
150 queue(p_em)->count--;
158 queue(p_em)->last_elmt=prev;
161 /**************************************************************************
162 * libvlc_event_async_fini (internal) :
164 * Destroy what might have been created by.
165 **************************************************************************/
167 libvlc_event_async_fini(libvlc_event_manager_t * p_em)
169 if(!is_queue_initialized(p_em)) return;
171 if(current_thread_is_asynch_thread(p_em))
173 fprintf(stderr, "*** Error: releasing the last reference of the observed object from its callback thread is not (yet!) supported\n");
177 vlc_thread_t thread = queue(p_em)->thread;
181 vlc_join(thread, NULL);
184 vlc_mutex_destroy(&queue(p_em)->lock);
185 vlc_cond_destroy(&queue(p_em)->signal);
186 vlc_cond_destroy(&queue(p_em)->signal_idle);
187 vlc_threadvar_delete(&queue(p_em)->is_asynch_dispatch_thread_var);
189 struct queue_elmt * iter = queue(p_em)->first_elmt;
191 struct queue_elmt * elemt_to_delete = iter;
193 free(elemt_to_delete);
199 /**************************************************************************
200 * libvlc_event_async_init (private) :
202 * Destroy what might have been created by.
203 **************************************************************************/
205 libvlc_event_async_init(libvlc_event_manager_t * p_em)
207 p_em->async_event_queue = calloc(1, sizeof(struct libvlc_event_async_queue));
209 int error = vlc_threadvar_create(&queue(p_em)->is_asynch_dispatch_thread_var, NULL);
212 vlc_mutex_init(&queue(p_em)->lock);
213 vlc_cond_init(&queue(p_em)->signal);
214 vlc_cond_init(&queue(p_em)->signal_idle);
216 error = vlc_clone (&queue(p_em)->thread, event_async_loop, p_em, VLC_THREAD_PRIORITY_LOW);
219 free(p_em->async_event_queue);
220 p_em->async_event_queue = NULL;
226 /**************************************************************************
227 * libvlc_event_async_ensure_listener_removal (internal) :
229 * Make sure no more message will be issued to the listener.
230 **************************************************************************/
232 libvlc_event_async_ensure_listener_removal(libvlc_event_manager_t * p_em, libvlc_event_listener_t * listener)
234 if(!is_queue_initialized(p_em)) return;
237 pop_listener(p_em, listener);
239 // Wait for the asynch_loop to have processed all events.
240 if(!current_thread_is_asynch_thread(p_em))
242 while(!queue(p_em)->is_idle)
243 vlc_cond_wait(&queue(p_em)->signal_idle, &queue(p_em)->lock);
248 /**************************************************************************
249 * libvlc_event_async_dispatch (internal) :
251 * Send an event in an asynchronous way.
252 **************************************************************************/
254 libvlc_event_async_dispatch(libvlc_event_manager_t * p_em, libvlc_event_listener_t * listener, libvlc_event_t * event)
256 // We do a lazy init here, to prevent constructing the thread when not needed.
257 vlc_mutex_lock(&p_em->object_lock);
259 libvlc_event_async_init(p_em);
260 vlc_mutex_unlock(&p_em->object_lock);
263 push(p_em, listener, event);
264 vlc_cond_signal(&queue(p_em)->signal);
268 /**************************************************************************
269 * event_async_loop (private) :
271 * Send queued events.
272 **************************************************************************/
273 static void * event_async_loop(void * arg)
275 libvlc_event_manager_t * p_em = arg;
276 libvlc_event_listener_t listener;
277 libvlc_event_t event;
279 vlc_threadvar_set(queue(p_em)->is_asynch_dispatch_thread_var, p_em);
283 int has_listener = pop(p_em, &listener, &event);
288 listener.pf_callback(&event, listener.p_user_data); // This might edit the queue
293 queue(p_em)->is_idle = true;
295 mutex_cleanup_push(&queue(p_em)->lock);
296 vlc_cond_broadcast(&queue(p_em)->signal_idle); // We'll be idle
297 vlc_cond_wait(&queue(p_em)->signal, &queue(p_em)->lock);
300 queue(p_em)->is_idle = false;