Changeset 0f8d02ae0dade744e73b415326337b772eba2495

Timestamp:

03/03/08 22:29:21 (6 months ago)

Author:

Pierre d'Herbemont <pdherbemont@free.fr>

git-committer:

Pierre d'Herbemont <pdherbemont@free.fr> 1204579761 +0100

git-parent:

[45dc363611bc200a2ee564994690394e26edd914]

git-author:

Pierre d'Herbemont <pdherbemont@free.fr> 1204579761 +0100

Message:

misc/objects.c:
* Fix a rare race condition that may happen because the refcount was changed outside of the structure lock.
* assert(refcount>0) in some key function to help to track freed object easily.
* Use vlc_object_yield_locked() instead of refcount++.

Files:

• src/misc/objects.c (modified) (16 diffs)

src/misc/objects.c

@@ -94 +94 @@
-
-static void vlc_object_destroy( vlc_object_t *p_this );
+static void vlc_object_yield_locked( vlc_object_t *p_this );
-
-/*****************************************************************************
@@ -733 +734 @@
-                if( pp_objects[i_middle+1]->i_object_id == i_id )
-                {
+                    vlc_object_yield_locked( pp_objects[i_middle+1] );
-                    vlc_mutex_unlock( &structure_lock );
-                    pp_objects[i_middle+1]->p_internals->i_refcount++;
-                    return pp_objects[i_middle+1];
-                }
@@ -742 +743 @@
-        else
-        {
+            vlc_object_yield_locked( pp_objects[i_middle] );
-            vlc_mutex_unlock( &structure_lock );
-            pp_objects[i_middle]->p_internals->i_refcount++;
-            return pp_objects[i_middle];
-        }
@@ -772 +773 @@
-    vlc_mutex_lock( &structure_lock );
-
+    /* Avoid obvious freed object uses */
+    assert( p_this->p_internals->i_refcount > 0 );
+
-    /* If we are of the requested type ourselves, don't look further */
-    if( !(i_mode & FIND_STRICT) && p_this->i_object_type == i_type )
-    {
-p_this->p_internals->i_refcount++
+vlc_object_yield_locked( p_this )
-        vlc_mutex_unlock( &structure_lock );
-        return p_this;
@@ -823 +827 @@
-    vlc_mutex_lock( &structure_lock );
-
+    /* Avoid obvious freed object uses */
+    assert( p_this->p_internals->i_refcount > 0 );
+
-    /* If have the requested name ourselves, don't look further */
-    if( !(i_mode & FIND_STRICT)
@@ -828 +835 @@
-        && !strcmp( p_this->psz_object_name, psz_name ) )
-    {
-p_this->p_internals->i_refcount++
+vlc_object_yield_locked( p_this )
-        vlc_mutex_unlock( &structure_lock );
-        return p_this;
@@ -867 +874 @@
- * increment an object refcount
- *****************************************************************************/
+
+/* When the structure_lock is locked */
+static void vlc_object_yield_locked( vlc_object_t *p_this )
+{
+    /* Avoid obvious freed object uses */
+    assert( p_this->p_internals->i_refcount > 0 );
+
+    /* Increment the counter */
+    p_this->p_internals->i_refcount++;
+}
+
+/* Public function */
-void __vlc_object_yield( vlc_object_t *p_this )
-{
-    vlc_mutex_lock( &structure_lock );
-p_this->p_internals->i_refcount++
+vlc_object_yield_locked( p_this )
-    vlc_mutex_unlock( &structure_lock );
-}
+
-
-/*****************************************************************************
@@ -922 +942 @@
-    vlc_mutex_lock( &structure_lock );
-
+    /* Avoid obvious freed object uses */
+    assert( p_this->p_internals->i_refcount > 0 );
+
-    /* Attach the parent to its child */
-    p_this->p_parent = p_parent;
@@ -949 +972 @@
-
-    vlc_mutex_lock( &structure_lock );
+
+    /* Avoid obvious freed object uses */
+    assert( p_this->p_internals->i_refcount > 0 );
+
-    if( !p_this->p_parent )
-    {
@@ -982 +1009 @@
-
-    vlc_mutex_lock( &structure_lock );
+
+    /* Avoid obvious freed object uses */
+    assert( p_this->p_internals->i_refcount > 0 );
-
-    /* Look for the objects */
@@ -1291 +1321 @@
-            if( p_tmp->i_object_type == i_type )
-            {
-p_tmp->p_internals->i_refcount++
+vlc_object_yield_locked( p_tmp )
-                return p_tmp;
-            }
@@ -1307 +1337 @@
-            if( p_tmp->i_object_type == i_type )
-            {
-p_tmp->p_internals->i_refcount++
+vlc_object_yield_locked( p_tmp )
-                return p_tmp;
-            }
@@ -1345 +1375 @@
-                && !strcmp( p_tmp->psz_object_name, psz_name ) )
-            {
-p_tmp->p_internals->i_refcount++
+vlc_object_yield_locked( p_tmp )
-                return p_tmp;
-            }
@@ -1362 +1392 @@
-                && !strcmp( p_tmp->psz_object_name, psz_name ) )
-            {
-p_tmp->p_internals->i_refcount++
+vlc_object_yield_locked( p_tmp )
-                return p_tmp;
-            }
@@ -1563 +1593 @@
-    }
-
-p_object->p_internals->i_refcount++
+vlc_object_yield_locked( p_object )
-
-    p_list->p_values[i_index].p_object = p_object;
@@ -1585 +1615 @@
-    }
-
-p_object->p_internals->i_refcount++
+vlc_object_yield_locked( p_object )
-
-    p_list->p_values[p_list->i_count].p_object = p_object;