From f82a731b3a09f2752c0475ff6e51757b8551868a Mon Sep 17 00:00:00 2001
From: Mathieu Duponchelle <mathieu@centricular.com>
Date: Fri, 7 Oct 2022 21:02:52 +0200
Subject: [PATCH] webrtcsink: fix deadlock on encoder setup

Refactor connect_input_stream in order to avoid an ABBA deadlock
altogether: where in other spots we lock settings then state, here we
were emitting encoder-setup with state held, then locking settings in
the default handler.

We could have changed the locking order in the other spots, but instead
we can also just release the state lock when emitting the signal, which
is good practice.

Fixes #108
---
 plugins/src/webrtcsink/imp.rs | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/plugins/src/webrtcsink/imp.rs b/plugins/src/webrtcsink/imp.rs
index 9ecb7b863..4d5687e89 100644
--- a/plugins/src/webrtcsink/imp.rs
+++ b/plugins/src/webrtcsink/imp.rs
@@ -75,7 +75,7 @@ struct Settings {
 }
 
 /// Represents a codec we can offer
-#[derive(Debug)]
+#[derive(Debug, Clone)]
 struct Codec {
     encoder: gst::ElementFactory,
     payloader: gst::ElementFactory,
@@ -1858,6 +1858,7 @@ impl WebRTCSink {
     fn on_remote_description_set(&self, element: &super::WebRTCSink, session_id: String) {
         let mut state = self.state.lock().unwrap();
         let mut remove = false;
+        let codecs = state.codecs.clone();
 
         if let Some(mut session) = state.sessions.remove(&session_id) {
             for webrtc_pad in session.webrtc_pads.clone().values() {
@@ -1874,10 +1875,11 @@ impl WebRTCSink {
                 if let Some(producer) = state
                     .streams
                     .get(&webrtc_pad.stream_name)
-                    .and_then(|stream| stream.producer.as_ref())
+                    .and_then(|stream| stream.producer.clone())
                 {
+                    drop(state);
                     if let Err(err) =
-                        session.connect_input_stream(element, producer, webrtc_pad, &state.codecs)
+                        session.connect_input_stream(element, &producer, webrtc_pad, &codecs)
                     {
                         gst::error!(
                             CAT,
@@ -1888,8 +1890,10 @@ impl WebRTCSink {
                             err
                         );
                         remove = true;
+                        state = self.state.lock().unwrap();
                         break;
                     }
+                    state = self.state.lock().unwrap();
                 } else {
                     gst::error!(
                         CAT,