lib: merge both event manager locks

The distinction was rather vain, as the inner lock was almost never
held without the outer lock. The only case was adding an event callback
(but _not_ removing one). On the other hand, the distinction required
extra heap manipulations and memory copying for each event.

lib/event.c

@@ -84,8 +84,7 @@ typedef struct libvlc_event_manager_t
 {
     void * p_obj;
     vlc_array_t listeners_groups;
-    vlc_mutex_t object_lock;
-    vlc_mutex_t event_sending_lock;
+    vlc_mutex_t lock;
 } libvlc_event_sender_t;
 
 
@@ -147,8 +146,7 @@ libvlc_event_manager_new( void * p_obj )
     p_em->p_obj = p_obj;
 
     vlc_array_init( &p_em->listeners_groups );
-    vlc_mutex_init( &p_em->object_lock );
-    vlc_mutex_init_recursive( &p_em->event_sending_lock );
+    vlc_mutex_init_recursive(&p_em->lock);
     return p_em;
 }
 
@@ -162,8 +160,7 @@ void libvlc_event_manager_release( libvlc_event_manager_t * p_em )
     libvlc_event_listeners_group_t * p_lg;
     int i,j ;
 
-    vlc_mutex_destroy( &p_em->event_sending_lock );
-    vlc_mutex_destroy( &p_em->object_lock );
+    vlc_mutex_destroy(&p_em->lock);
 
     for( i = 0; i < vlc_array_count(&p_em->listeners_groups); i++)
     {
@@ -193,9 +190,9 @@ void libvlc_event_manager_register_event_type(
     listeners_group->event_type = event_type;
     vlc_array_init( &listeners_group->listeners );
 
-    vlc_mutex_lock( &p_em->object_lock );
+    vlc_mutex_lock(&p_em->lock);
     vlc_array_append( &p_em->listeners_groups, listeners_group );
-    vlc_mutex_unlock( &p_em->object_lock );
+    vlc_mutex_unlock(&p_em->lock);
 }
 
 /**************************************************************************
@@ -215,8 +212,7 @@ void libvlc_event_send( libvlc_event_manager_t * p_em,
     /* 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 );
+    vlc_mutex_lock(&p_em->lock);
     for( i = 0; i < vlc_array_count(&p_em->listeners_groups); i++)
     {
         listeners_group = vlc_array_item_at_index(&p_em->listeners_groups, i);
@@ -231,8 +227,7 @@ void libvlc_event_send( libvlc_event_manager_t * p_em,
             array_listeners_cached = malloc(sizeof(libvlc_event_listener_t)*(i_cached_listeners));
             if( !array_listeners_cached )
             {
-                vlc_mutex_unlock( &p_em->object_lock );
-                vlc_mutex_unlock( &p_em->event_sending_lock );
+                vlc_mutex_unlock(&p_em->lock);
                 fprintf(stderr, "Can't alloc memory in libvlc_event_send" );
                 return;
             }
@@ -250,9 +245,8 @@ void libvlc_event_send( libvlc_event_manager_t * p_em,
 
     if( !listeners_group )
     {
+        vlc_mutex_unlock(&p_em->lock);
         free( array_listeners_cached );
-        vlc_mutex_unlock( &p_em->object_lock );
-        vlc_mutex_unlock( &p_em->event_sending_lock );
         return;
     }
 
@@ -261,8 +255,6 @@ void libvlc_event_send( libvlc_event_manager_t * p_em,
      * allowing to remove an event listener from within a callback */
     listeners_group->b_sublistener_removed = false;
 
-    vlc_mutex_unlock( &p_em->object_lock );
-
     listener_cached = array_listeners_cached;
     for( i = 0; i < i_cached_listeners; i++ )
     {
@@ -274,9 +266,7 @@ void libvlc_event_send( libvlc_event_manager_t * p_em,
         {
             /* If a callback was removed, this gets called */
             bool valid_listener;
-            vlc_mutex_lock( &p_em->object_lock );
             valid_listener = group_contains_listener( listeners_group, listener_cached );
-            vlc_mutex_unlock( &p_em->object_lock );
             if( !valid_listener )
             {
                 listener_cached++;
@@ -284,7 +274,7 @@ void libvlc_event_send( libvlc_event_manager_t * p_em,
             }
         }
     }
-    vlc_mutex_unlock( &p_em->event_sending_lock );
+    vlc_mutex_unlock(&p_em->lock);
 
     free( array_listeners_cached );
 }
@@ -410,18 +400,18 @@ int event_attach( libvlc_event_manager_t * p_event_manager,
     listener->p_user_data = p_user_data;
     listener->pf_callback = pf_callback;
 
-    vlc_mutex_lock( &p_event_manager->object_lock );
+    vlc_mutex_lock(&p_event_manager->lock);
     for( i = 0; i < vlc_array_count(&p_event_manager->listeners_groups); i++ )
     {
         listeners_group = vlc_array_item_at_index(&p_event_manager->listeners_groups, i);
         if( listeners_group->event_type == listener->event_type )
         {
             vlc_array_append( &listeners_group->listeners, listener );
-            vlc_mutex_unlock( &p_event_manager->object_lock );
+            vlc_mutex_unlock(&p_event_manager->lock);
             return 0;
         }
     }
-    vlc_mutex_unlock( &p_event_manager->object_lock );
+    vlc_mutex_unlock(&p_event_manager->lock);
 
     free(listener);
     fprintf( stderr, "This object event manager doesn't know about '%s' events",
@@ -458,8 +448,7 @@ void libvlc_event_detach( libvlc_event_manager_t *p_event_manager,
     int i, j;
     bool found = false;
 
-    vlc_mutex_lock( &p_event_manager->event_sending_lock );
-    vlc_mutex_lock( &p_event_manager->object_lock );
+    vlc_mutex_lock(&p_event_manager->lock);
     for( i = 0; i < vlc_array_count(&p_event_manager->listeners_groups); i++)
     {
         listeners_group = vlc_array_item_at_index(&p_event_manager->listeners_groups, i);
@@ -486,8 +475,7 @@ void libvlc_event_detach( libvlc_event_manager_t *p_event_manager,
             }
         }
     }
-    vlc_mutex_unlock( &p_event_manager->object_lock );
-    vlc_mutex_unlock( &p_event_manager->event_sending_lock );
+    vlc_mutex_unlock(&p_event_manager->lock);
 
     assert(found);
 }