Revert "vlc_object_release: cleanup"

This reverts commit c85f8681.

src/misc/objects.c

@@ -840,23 +840,32 @@ void __vlc_object_yield( vlc_object_t *p_this )
 void __vlc_object_release( vlc_object_t *p_this )
 {
     vlc_object_internals_t *internals = vlc_internals( p_this );
+    bool b_should_destroy;
 
     vlc_spin_lock( &internals->ref_spin );
     assert( internals->i_refcount > 0 );
 
-    if( --internals->i_refcount )
+    if( internals->i_refcount > 1 )
     {
         /* Fast path */
         /* There are still other references to the object */
+        internals->i_refcount--;
         vlc_spin_unlock( &internals->ref_spin );
         return;
     }
     vlc_spin_unlock( &internals->ref_spin );
 
-    /* Slow path : object destruction */
+    /* Slow path */
     /* Remember that we cannot hold the spin while waiting on the mutex */
     vlc_mutex_lock( &structure_lock );
+    /* Take the spin again. Note that another thread may have yielded the
+     * object in the (very short) mean time. */
+    vlc_spin_lock( &internals->ref_spin );
+    b_should_destroy = --internals->i_refcount == 0;
+    vlc_spin_unlock( &internals->ref_spin );
 
+    if( b_should_destroy )
+    {
         /* Remove the object from the table
          * so that it cannot be encountered by vlc_object_get() */
         libvlc_global_data_t *p_libvlc_global = vlc_global();
@@ -873,9 +882,11 @@ void __vlc_object_release( vlc_object_t *p_this )
         /* Detach from children to protect against FIND_PARENT */
         for (int i = 0; i < p_this->i_children; i++)
             p_this->pp_children[i]->p_parent = NULL;
+    }
 
     vlc_mutex_unlock( &structure_lock );
 
+    if( b_should_destroy )
         vlc_object_destroy( p_this );
 }