From a005cf8e05aaff916e72e9df7aaafa46a7f996af Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Sebastian=20Dr=C3=B6ge?= <sebastian@centricular.com>
Date: Mon, 18 Aug 2025 13:08:07 +0300
Subject: [PATCH] fallbacksrc: Don't keep CustomSource state locked while
 adding/removing pads

Part-of: <https://gitlab.freedesktop.org/gstreamer/gst-plugins-rs/-/merge_requests/2474>
---
 .../src/fallbacksrc/custom_source/imp.rs      | 20 +++++++++++++++----
 1 file changed, 16 insertions(+), 4 deletions(-)

diff --git a/utils/fallbackswitch/src/fallbacksrc/custom_source/imp.rs b/utils/fallbackswitch/src/fallbacksrc/custom_source/imp.rs
index d906eb8cd..437153358 100644
--- a/utils/fallbackswitch/src/fallbacksrc/custom_source/imp.rs
+++ b/utils/fallbackswitch/src/fallbacksrc/custom_source/imp.rs
@@ -608,23 +608,35 @@ impl CustomSource {
             .src(&*self.obj())
             .build();
 
-        self.expose_only_selected_streams(state);
+        self.expose_only_selected_streams(state_guard);
         Some(message)
     }
 
-    fn expose_only_selected_streams(&self, state: &mut State) {
+    fn expose_only_selected_streams(&self, state: MutexGuard<State>) {
+        let mut to_add = vec![];
+        let mut to_remove = vec![];
+
         for stream in state.pads.iter() {
             if stream.is_selected && !stream.is_exposed() {
                 let event = gst::event::StreamStart::builder(&stream.stream.stream_id().unwrap())
                     .stream(stream.stream.clone())
                     .build();
                 stream.ghost_pad.store_sticky_event(&event).unwrap();
-                self.obj().add_pad(&stream.ghost_pad).unwrap();
+                to_add.push(stream.ghost_pad.clone());
             } else if !stream.is_selected && stream.is_exposed() {
                 let _ = stream.ghost_pad.set_target(None::<&gst::Pad>);
-                let _ = self.obj().remove_pad(&stream.ghost_pad);
+                to_remove.push(stream.ghost_pad.clone());
             }
         }
+        drop(state);
+
+        for pad in to_add {
+            self.obj().add_pad(&pad).unwrap();
+        }
+
+        for pad in to_remove {
+            let _ = self.obj().remove_pad(&pad);
+        }
     }
 
     fn stop(&self) {