* events.c: events interface
* This library provides an interface to the send and receive events.
* It is more lightweight than variable based callback.
- * Methode
*****************************************************************************
- * Copyright (C) 1998-2005 the VideoLAN team
+ * Copyright (C) 1998-2005 VLC authors and VideoLAN
* $Id$
*
* Authors: Pierre d'Herbemont <pdherbemont # videolan.org >
*
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation; either version 2.1 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Lesser General Public License for more details.
*
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
*****************************************************************************/
/*****************************************************************************
* Preamble
*****************************************************************************/
-#include <vlc/vlc.h>
+#ifdef HAVE_CONFIG_H
+# include "config.h"
+#endif
-#include <stdio.h> /* required */
-#include <stdlib.h> /* malloc() */
+#include <vlc_common.h>
#include <assert.h>
{
vlc_event_type_t event_type;
DECL_ARRAY(struct vlc_event_listener_t *) listeners;
+
+ /* Used in vlc_event_send() to make sure to behave
+ Correctly when vlc_event_detach was called during
+ a callback */
+ bool b_sublistener_removed;
+
} vlc_event_listeners_group_t;
+static bool
+listeners_are_equal( vlc_event_listener_t * listener1,
+ vlc_event_listener_t * listener2 )
+{
+ return listener1->pf_callback == listener2->pf_callback &&
+ listener1->p_user_data == listener2->p_user_data;
+}
+
+static bool
+group_contains_listener( vlc_event_listeners_group_t * group,
+ vlc_event_listener_t * searched_listener )
+{
+ vlc_event_listener_t * listener;
+ FOREACH_ARRAY( listener, group->listeners )
+ if( listeners_are_equal(searched_listener, listener) )
+ return true;
+ FOREACH_END()
+ return false;
+}
+
/*****************************************************************************
- *
+ *
*****************************************************************************/
+#undef vlc_event_manager_init
/**
* Initialize event manager object
- * p_this is the object that contains the event manager. But not
+ * p_obj is the object that contains the event manager. But not
* necessarily a vlc_object_t (an input_item_t is not a vlc_object_t
* for instance).
*/
int vlc_event_manager_init( vlc_event_manager_t * p_em, void * p_obj )
{
p_em->p_obj = p_obj;
+ vlc_mutex_init( &p_em->object_lock );
+
+ /* We need a recursive lock here, because we need to be able
+ * to call libvlc_event_detach even if vlc_event_send is in
+ * the call frame.
+ * This ensures that after libvlc_event_detach, the callback
+ * will never gets triggered.
+ * */
+ vlc_mutex_init_recursive( &p_em->event_sending_lock );
ARRAY_INIT( p_em->listeners_groups );
return VLC_SUCCESS;
}
struct vlc_event_listeners_group_t * listeners_group;
struct vlc_event_listener_t * listener;
+ vlc_mutex_destroy( &p_em->object_lock );
+ vlc_mutex_destroy( &p_em->event_sending_lock );
+
FOREACH_ARRAY( listeners_group, p_em->listeners_groups )
FOREACH_ARRAY( listener, listeners_group->listeners )
free( listener );
FOREACH_END()
+ ARRAY_RESET( listeners_group->listeners );
free( listeners_group );
FOREACH_END()
- free( p_em );
+ ARRAY_RESET( p_em->listeners_groups );
}
/**
- * Destroy the event manager
+ * Register the event manager
*/
int vlc_event_manager_register_event_type(
vlc_event_manager_t * p_em,
listeners_group->event_type = event_type;
ARRAY_INIT( listeners_group->listeners );
-
+
+ vlc_mutex_lock( &p_em->object_lock );
ARRAY_APPEND( p_em->listeners_groups, listeners_group );
+ vlc_mutex_unlock( &p_em->object_lock );
return VLC_SUCCESS;
}
void vlc_event_send( vlc_event_manager_t * p_em,
vlc_event_t * p_event )
{
- vlc_event_listeners_group_t * listeners_group;
+ vlc_event_listeners_group_t * listeners_group = NULL;
vlc_event_listener_t * listener;
+ vlc_event_listener_t * array_of_cached_listeners = NULL;
+ vlc_event_listener_t * cached_listener;
+ int i, i_cached_listeners = 0;
/* Fill event with the sending object now */
p_event->p_obj = p_em->p_obj;
+ vlc_mutex_lock( &p_em->event_sending_lock ) ;
+ vlc_mutex_lock( &p_em->object_lock );
+
FOREACH_ARRAY( listeners_group, p_em->listeners_groups )
if( listeners_group->event_type == p_event->type )
{
- /* We found the group, now send every one the event */
+ if( listeners_group->listeners.i_size <= 0 )
+ break;
+
+ /* Save the function to call */
+ i_cached_listeners = listeners_group->listeners.i_size;
+ array_of_cached_listeners = malloc(
+ sizeof(vlc_event_listener_t)*i_cached_listeners );
+ if( !array_of_cached_listeners )
+ {
+ vlc_mutex_unlock( &p_em->object_lock );
+ vlc_mutex_unlock( &p_em->event_sending_lock ) ;
+ return;
+ }
+
+ cached_listener = array_of_cached_listeners;
FOREACH_ARRAY( listener, listeners_group->listeners )
- listener->pf_callback( p_event, listener->p_user_data );
+ memcpy( cached_listener, listener, sizeof(vlc_event_listener_t));
+ cached_listener++;
FOREACH_END()
+
break;
}
FOREACH_END()
+
+ /* Track item removed from *this* thread, with a simple flag. Indeed
+ * event_sending_lock is a recursive lock. This has the advantage of
+ * allowing to remove an event listener from within a callback */
+ listeners_group->b_sublistener_removed = false;
+
+ vlc_mutex_unlock( &p_em->object_lock );
+
+ /* Call the function attached */
+ cached_listener = array_of_cached_listeners;
+
+ if( !listeners_group || !array_of_cached_listeners )
+ {
+ free( array_of_cached_listeners );
+ vlc_mutex_unlock( &p_em->event_sending_lock );
+ return;
+ }
+
+
+ for( i = 0; i < i_cached_listeners; i++ )
+ {
+ if( listeners_group->b_sublistener_removed )
+ {
+ /* If a callback was removed inside one of our callback, this gets
+ * called */
+ bool valid_listener;
+ vlc_mutex_lock( &p_em->object_lock );
+ valid_listener = group_contains_listener( listeners_group, cached_listener );
+ vlc_mutex_unlock( &p_em->object_lock );
+ if( !valid_listener )
+ {
+ cached_listener++;
+ continue;
+ }
+ }
+ cached_listener->pf_callback( p_event, cached_listener->p_user_data );
+ cached_listener++;
+ }
+ vlc_mutex_unlock( &p_em->event_sending_lock );
+
+ free( array_of_cached_listeners );
}
+#undef vlc_event_attach
/**
* Add a callback for an event.
*/
-int vlc_event_attach( vlc_event_manager_t * p_event_manager,
+int vlc_event_attach( vlc_event_manager_t * p_em,
vlc_event_type_t event_type,
vlc_event_callback_t pf_callback,
void *p_user_data )
listener = malloc(sizeof(vlc_event_listener_t));
if( !listener )
return VLC_ENOMEM;
-
+
listener->p_user_data = p_user_data;
listener->pf_callback = pf_callback;
-
- FOREACH_ARRAY( listeners_group, p_event_manager->listeners_groups )
+
+ vlc_mutex_lock( &p_em->object_lock );
+ FOREACH_ARRAY( listeners_group, p_em->listeners_groups )
if( listeners_group->event_type == event_type )
{
ARRAY_APPEND( listeners_group->listeners, listener );
+ vlc_mutex_unlock( &p_em->object_lock );
return VLC_SUCCESS;
}
FOREACH_END()
-
- free(listener);
- return VLC_EGENERIC;
+ /* Unknown event = BUG */
+ assert( 0 );
}
/**
* Remove a callback for an event.
*/
-int vlc_event_detach( vlc_event_manager_t *p_event_manager,
- vlc_event_type_t event_type,
- vlc_event_callback_t pf_callback,
- void *p_user_data )
+
+void vlc_event_detach( vlc_event_manager_t *p_em,
+ vlc_event_type_t event_type,
+ vlc_event_callback_t pf_callback,
+ void *p_user_data )
{
vlc_event_listeners_group_t * listeners_group;
struct vlc_event_listener_t * listener;
- FOREACH_ARRAY( listeners_group, p_event_manager->listeners_groups )
+
+ vlc_mutex_lock( &p_em->event_sending_lock );
+ vlc_mutex_lock( &p_em->object_lock );
+ FOREACH_ARRAY( listeners_group, p_em->listeners_groups )
if( listeners_group->event_type == event_type )
{
FOREACH_ARRAY( listener, listeners_group->listeners )
if( listener->pf_callback == pf_callback &&
listener->p_user_data == p_user_data )
{
+ /* Tell vlc_event_send, we did remove an item from that group,
+ in case vlc_event_send is in our caller stack */
+ listeners_group->b_sublistener_removed = true;
+
/* that's our listener */
- free( listener );
ARRAY_REMOVE( listeners_group->listeners,
fe_idx /* This comes from the macro (and that's why
I hate macro) */ );
- return VLC_SUCCESS;
+ free( listener );
+ vlc_mutex_unlock( &p_em->event_sending_lock );
+ vlc_mutex_unlock( &p_em->object_lock );
+ return;
}
FOREACH_END()
}
FOREACH_END()
- return VLC_EGENERIC;
+ assert( 0 );
}
-
-
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