Commit 673d6562 authored by Rafaël Carré's avatar Rafaël Carré

Fix #5706

Properly take the recursive event_sending_lock when looking for listener to
send the event.
Ensure that there will be no event dispatch after vlc_event_detach().

Also, fix a bug in libvlc_event where removing an event handler from an event
callback would lead to a crash.
parent d771dd56
...@@ -157,8 +157,7 @@ void libvlc_event_send( libvlc_event_manager_t * p_em, ...@@ -157,8 +157,7 @@ void libvlc_event_send( libvlc_event_manager_t * p_em,
/* Fill event with the sending object now */ /* Fill event with the sending object now */
p_event->p_obj = p_em->p_obj; p_event->p_obj = p_em->p_obj;
/* Here a read/write lock would be nice */ vlc_mutex_lock( &p_em->event_sending_lock );
vlc_mutex_lock( &p_em->object_lock ); vlc_mutex_lock( &p_em->object_lock );
for( i = 0; i < vlc_array_count(&p_em->listeners_groups); i++) for( i = 0; i < vlc_array_count(&p_em->listeners_groups); i++)
{ {
...@@ -175,6 +174,7 @@ void libvlc_event_send( libvlc_event_manager_t * p_em, ...@@ -175,6 +174,7 @@ void libvlc_event_send( libvlc_event_manager_t * p_em,
if( !array_listeners_cached ) if( !array_listeners_cached )
{ {
vlc_mutex_unlock( &p_em->object_lock ); vlc_mutex_unlock( &p_em->object_lock );
vlc_mutex_unlock( &p_em->event_sending_lock );
fprintf(stderr, "Can't alloc memory in libvlc_event_send" ); fprintf(stderr, "Can't alloc memory in libvlc_event_send" );
return; return;
} }
...@@ -194,14 +194,18 @@ void libvlc_event_send( libvlc_event_manager_t * p_em, ...@@ -194,14 +194,18 @@ void libvlc_event_send( libvlc_event_manager_t * p_em,
{ {
free( array_listeners_cached ); free( array_listeners_cached );
vlc_mutex_unlock( &p_em->object_lock ); vlc_mutex_unlock( &p_em->object_lock );
vlc_mutex_unlock( &p_em->event_sending_lock );
return; return;
} }
/* 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 ); vlc_mutex_unlock( &p_em->object_lock );
vlc_mutex_lock( &p_em->event_sending_lock );
listener_cached = array_listeners_cached; listener_cached = array_listeners_cached;
listeners_group->b_sublistener_removed = false;
for( i = 0; i < i_cached_listeners; i++ ) for( i = 0; i < i_cached_listeners; i++ )
{ {
if(listener_cached->is_asynchronous) if(listener_cached->is_asynchronous)
...@@ -424,7 +428,7 @@ void libvlc_event_detach( libvlc_event_manager_t *p_event_manager, ...@@ -424,7 +428,7 @@ void libvlc_event_detach( libvlc_event_manager_t *p_event_manager,
/* Mark this group as edited so that libvlc_event_send /* Mark this group as edited so that libvlc_event_send
* will recheck what listener to call */ * will recheck what listener to call */
listeners_group->b_sublistener_removed = false; listeners_group->b_sublistener_removed = true;
free( listener ); free( listener );
vlc_array_remove( &listeners_group->listeners, j ); vlc_array_remove( &listeners_group->listeners, j );
......
...@@ -170,7 +170,9 @@ void vlc_event_send( vlc_event_manager_t * p_em, ...@@ -170,7 +170,9 @@ void vlc_event_send( vlc_event_manager_t * p_em,
/* Fill event with the sending object now */ /* Fill event with the sending object now */
p_event->p_obj = p_em->p_obj; p_event->p_obj = p_em->p_obj;
vlc_mutex_lock( &p_em->event_sending_lock ) ;
vlc_mutex_lock( &p_em->object_lock ); vlc_mutex_lock( &p_em->object_lock );
FOREACH_ARRAY( listeners_group, p_em->listeners_groups ) FOREACH_ARRAY( listeners_group, p_em->listeners_groups )
if( listeners_group->event_type == p_event->type ) if( listeners_group->event_type == p_event->type )
{ {
...@@ -184,6 +186,7 @@ void vlc_event_send( vlc_event_manager_t * p_em, ...@@ -184,6 +186,7 @@ void vlc_event_send( vlc_event_manager_t * p_em,
if( !array_of_cached_listeners ) if( !array_of_cached_listeners )
{ {
vlc_mutex_unlock( &p_em->object_lock ); vlc_mutex_unlock( &p_em->object_lock );
vlc_mutex_unlock( &p_em->event_sending_lock ) ;
return; return;
} }
...@@ -196,28 +199,31 @@ void vlc_event_send( vlc_event_manager_t * p_em, ...@@ -196,28 +199,31 @@ void vlc_event_send( vlc_event_manager_t * p_em,
break; break;
} }
FOREACH_END() 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 ); vlc_mutex_unlock( &p_em->object_lock );
/* Call the function attached */ /* Call the function attached */
cached_listener = array_of_cached_listeners; cached_listener = array_of_cached_listeners;
if( !listeners_group || !array_of_cached_listeners ) if( !listeners_group || !array_of_cached_listeners )
{ {
free( array_of_cached_listeners ); free( array_of_cached_listeners );
vlc_mutex_unlock( &p_em->event_sending_lock );
return; return;
} }
vlc_mutex_lock( &p_em->event_sending_lock ) ;
/* Track item removed from *this* thread, with a simple flag */
listeners_group->b_sublistener_removed = false;
for( i = 0; i < i_cached_listeners; i++ ) for( i = 0; i < i_cached_listeners; i++ )
{ {
/* No need to lock on listeners_group, a listener group can't be removed */
if( listeners_group->b_sublistener_removed ) if( listeners_group->b_sublistener_removed )
{ {
/* If a callback was removed, this gets called */ /* If a callback was removed inside one of our callback, this gets
* called */
bool valid_listener; bool valid_listener;
vlc_mutex_lock( &p_em->object_lock ); vlc_mutex_lock( &p_em->object_lock );
valid_listener = group_contains_listener( listeners_group, cached_listener ); valid_listener = group_contains_listener( listeners_group, cached_listener );
......
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