nlecomposition: Suppress error from child during sync state with parent

This commit is to ensure cleanup internal elements on state change failure.

nlecomposition posts its own error message after cleanup child.
If we don't suppress child error, meanwhile, an application
triggered downward state change (resulting from child error message)
might be able to reach nlecomposition before internal cleaning child up.
That eventually results to downward state change failure.

diff --git a/plugins/nle/nlecomposition.c b/plugins/nle/nlecomposition.c
index 363f873..85be290 100644 (file)
--- a/plugins/nle/nlecomposition.c
+++ b/plugins/nle/nlecomposition.c
@@ -196,6 +196,7 @@ struct _NleCompositionPrivate
   gboolean waiting_serialized_query_or_buffer;
 
   gboolean tearing_down_stack;
+  gboolean suppress_child_error;
 
   NleUpdateStackReason updating_reason;
 };
@@ -940,22 +941,29 @@ static void
 nle_composition_handle_message (GstBin * bin, GstMessage * message)
 {
   NleComposition *comp = (NleComposition *) bin;
+  NleCompositionPrivate *priv = comp->priv;
 
-  if (comp->priv->tearing_down_stack) {
-    if (GST_MESSAGE_TYPE (message) == GST_MESSAGE_ERROR) {
-      GST_FIXME_OBJECT (comp, "Dropping %" GST_PTR_FORMAT " message from "
-          " %" GST_PTR_FORMAT " being teared down to READY",
-          message, GST_MESSAGE_SRC (message));
-    }
-
+  if (GST_MESSAGE_TYPE (message) == GST_MESSAGE_ERROR &&
+      (priv->tearing_down_stack || priv->suppress_child_error)) {
+    GST_FIXME_OBJECT (comp, "Dropping %" GST_PTR_FORMAT " message from "
+        " %" GST_PTR_FORMAT " tearing down: %d, suppressing error: %d",
+        message, GST_MESSAGE_SRC (message), priv->tearing_down_stack,
+        priv->suppress_child_error);
+    goto drop;
+  } else if (comp->priv->tearing_down_stack) {
     GST_DEBUG_OBJECT (comp, "Dropping message %" GST_PTR_FORMAT " from "
         "object being teared down to READY!", message);
-    gst_message_unref (message);
-
-    return;
+    goto drop;
   }
 
   GST_BIN_CLASS (parent_class)->handle_message (bin, message);
+
+  return;
+
+drop:
+  gst_message_unref (message);
+
+  return;
 }
 
 static void
@@ -2902,9 +2910,11 @@ resync_state:
   gst_element_set_locked_state (priv->current_bin, FALSE);
 
   GST_DEBUG ("going back to parent state");
+  priv->suppress_child_error = TRUE;
   if (!gst_element_sync_state_with_parent (priv->current_bin)) {
     gst_element_set_locked_state (priv->current_bin, TRUE);
     gst_element_set_state (priv->current_bin, GST_STATE_NULL);
+    priv->suppress_child_error = FALSE;
 
     GST_ELEMENT_ERROR (comp, CORE, STATE_CHANGE, (NULL),
         ("Could not sync %" GST_PTR_FORMAT " state with parent",
@@ -2912,6 +2922,7 @@ resync_state:
     return FALSE;
   }
 
+  priv->suppress_child_error = FALSE;
   GST_DEBUG ("gone back to parent state");
 
   return TRUE;