]> git.sesse.net Git - vlc/blobdiff - src/misc/events.c
Coding convention
[vlc] / src / misc / events.c
index b5ac50cda2e538cf25eb177f5098d8dfade7c4be..9960ac172dee22bed0684e0b3f81e9f48fc95ed1 100644 (file)
  * Preamble
  *****************************************************************************/
 
+#ifdef HAVE_CONFIG_H
+# include "config.h"
+#endif
+
 #include <vlc/vlc.h>
 
 #include <assert.h>
@@ -58,10 +62,16 @@ typedef struct vlc_event_listeners_group_t
 {
     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 */
+    vlc_bool_t          b_sublistener_removed;
+                                         
 } vlc_event_listeners_group_t;
 
 #ifdef DEBUG_EVENT
-static const char * ppsz_event_type_to_name[] = 
+static const char * ppsz_event_type_to_name[] =
 {
     [vlc_InputItemMetaChanged]          = "vlc_InputItemMetaChanged",
     [vlc_InputItemSubItemAdded]         = "vlc_InputItemSubItemAdded",
@@ -70,8 +80,28 @@ static const char * ppsz_event_type_to_name[] =
 };
 #endif
 
+static vlc_bool_t
+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 vlc_bool_t
+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 VLC_TRUE;
+    FOREACH_END()
+    return VLC_FALSE;
+}
+
 /*****************************************************************************
- * 
+ *
  *****************************************************************************/
 
 /**
@@ -87,6 +117,14 @@ int vlc_event_manager_init( vlc_event_manager_t * p_em, void * p_obj,
     p_em->p_obj = p_obj;
     p_em->p_parent_object = p_parent_obj;
     vlc_mutex_init( p_parent_obj, &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_parent_obj, &p_em->event_sending_lock );
     ARRAY_INIT( p_em->listeners_groups );
     return VLC_SUCCESS;
 }
@@ -100,13 +138,16 @@ void vlc_event_manager_fini( vlc_event_manager_t * p_em )
     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()
+    ARRAY_RESET( p_em->listeners_groups );
 }
 
 /**
@@ -124,7 +165,7 @@ int vlc_event_manager_register_event_type(
 
     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 );
@@ -138,7 +179,7 @@ int vlc_event_manager_register_event_type(
 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;
@@ -161,6 +202,7 @@ void vlc_event_send( vlc_event_manager_t * p_em,
             if( !array_of_cached_listeners )
             {
                 msg_Err( p_em->p_parent_object, "Not enough memory in vlc_event_send" );
+                vlc_mutex_unlock( &p_em->object_lock );
                 return;
             }
 
@@ -170,16 +212,28 @@ void vlc_event_send( vlc_event_manager_t * p_em,
 #ifdef DEBUG_EVENT
                 cached_listener->psz_debug_name = strdup(cached_listener->psz_debug_name);
 #endif
-                cached_listener += sizeof(vlc_event_listener_t);
+                cached_listener++;
             FOREACH_END()
 
             break;
         }
     FOREACH_END()
     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 );
+        return;
+    }
+
+    vlc_mutex_lock( &p_em->event_sending_lock ) ;
+
+    /* Track item removed from *this* thread, with a simple flag */
+    listeners_group->b_sublistener_removed = VLC_FALSE;
+
     for( i = 0; i < i_cached_listeners; i++ )
     {
 #ifdef DEBUG_EVENT
@@ -188,14 +242,31 @@ void vlc_event_send( vlc_event_manager_t * p_em,
                     cached_listener->psz_debug_name,
                     ppsz_event_type_to_name[p_event->type],
                     cached_listener->p_user_data );
-        free(psz_debug_name);
+        free(cached_listener->psz_debug_name);
 #endif
-
+        /* No need to lock on listeners_group, a listener group can't be removed */
+        if( listeners_group->b_sublistener_removed )
+        {
+            /* If a callback was removed, this gets called */
+            vlc_bool_t 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 )
+            {
+#ifdef DEBUG_EVENT
+                msg_Dbg( p_em->p_parent_object, "Callback was removed during execution" );
+#endif
+                cached_listener++;
+                continue;
+            }
+        }
         cached_listener->pf_callback( p_event, cached_listener->p_user_data );
-        cached_listener += sizeof(vlc_event_listener_t) ;
+        cached_listener++;
     }
-    free( array_of_cached_listeners );
+    vlc_mutex_unlock( &p_em->event_sending_lock );
 
+    free( array_of_cached_listeners );
 }
 
 /**
@@ -212,7 +283,7 @@ int __vlc_event_attach( vlc_event_manager_t * p_em,
     listener = malloc(sizeof(vlc_event_listener_t));
     if( !listener )
         return VLC_ENOMEM;
-    
     listener->p_user_data = p_user_data;
     listener->pf_callback = pf_callback;
 #ifdef DEBUG_EVENT
@@ -247,6 +318,7 @@ int __vlc_event_attach( vlc_event_manager_t * p_em,
 /**
  * Remove a callback for an event.
  */
+
 int vlc_event_detach( vlc_event_manager_t *p_em,
                       vlc_event_type_t event_type,
                       vlc_event_callback_t pf_callback,
@@ -256,6 +328,7 @@ int vlc_event_detach( vlc_event_manager_t *p_em,
     struct vlc_event_listener_t * listener;
 
     vlc_mutex_lock( &p_em->object_lock );
+    vlc_mutex_lock( &p_em->event_sending_lock );
     FOREACH_ARRAY( listeners_group, p_em->listeners_groups )
         if( listeners_group->event_type == event_type )
         {
@@ -263,6 +336,10 @@ int vlc_event_detach( vlc_event_manager_t *p_em,
                 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 = VLC_TRUE;
+
                     /* that's our listener */
                     ARRAY_REMOVE( listeners_group->listeners,
                         fe_idx /* This comes from the macro (and that's why
@@ -277,15 +354,18 @@ int vlc_event_detach( vlc_event_manager_t *p_em,
                     free( listener->psz_debug_name );
 #endif
                     free( listener );
+                    vlc_mutex_unlock( &p_em->event_sending_lock );
                     vlc_mutex_unlock( &p_em->object_lock );
                     return VLC_SUCCESS;
                 }
             FOREACH_END()
         }
     FOREACH_END()
+    vlc_mutex_unlock( &p_em->event_sending_lock );
     vlc_mutex_unlock( &p_em->object_lock );
 
     msg_Warn( p_em->p_parent_object, "Can't detach to an object event manager event" );
 
     return VLC_EGENERIC;
 }
+