webrtcsink: expose signaller as a property

in the process move the signaller field to the settings struct

Part-of: <https://gitlab.freedesktop.org/gstreamer/gst-plugins-rs/-/merge_requests/1141>

net/webrtc/src/webrtcsink/imp.rs

@@ -16,6 +16,7 @@ use once_cell::sync::Lazy;
 use std::collections::HashMap;
 use std::ops::Mul;
 use std::sync::Mutex;
+use std::sync::MutexGuard;
 
 use super::homegrown_cc::CongestionController;
 use super::{WebRTCSinkCongestionControl, WebRTCSinkError, WebRTCSinkMitigationMode};
@@ -78,6 +79,7 @@ struct Settings {
     enable_data_channel_navigation: bool,
     meta: Option<gst::Structure>,
     ice_transport_policy: WebRTCICETransportPolicy,
+    signaller: Signallable,
 }
 
 /// Represents a codec we can offer
@@ -174,7 +176,7 @@ struct Session {
     codecs: Option<BTreeMap<i32, Codec>>,
 }
 
-#[derive(PartialEq)]
+#[derive(Debug, PartialEq, Eq, Copy, Clone)]
 enum SignallerState {
     Started,
     Stopped,
@@ -201,7 +203,6 @@ struct SignallerSignals {
 
 /* Our internal state */
 struct State {
-    signaller: Signallable,
     signaller_state: SignallerState,
     sessions: HashMap<String, Session>,
     codecs: BTreeMap<i32, Codec>,
@@ -288,6 +289,8 @@ pub struct WebRTCSink {
 
 impl Default for Settings {
     fn default() -> Self {
+        let signaller = Signaller::new(WebRTCSignallerRole::Producer);
+
         Self {
             video_caps: ["video/x-vp8", "video/x-h264", "video/x-vp9", "video/x-h265"]
                 .into_iter()
@@ -310,16 +313,14 @@ impl Default for Settings {
             enable_data_channel_navigation: DEFAULT_ENABLE_DATA_CHANNEL_NAVIGATION,
             meta: None,
             ice_transport_policy: DEFAULT_ICE_TRANSPORT_POLICY,
+            signaller: signaller.upcast(),
         }
     }
 }
 
 impl Default for State {
     fn default() -> Self {
-        let signaller = Signaller::new(WebRTCSignallerRole::Producer);
-
         Self {
-            signaller: signaller.upcast(),
             signaller_state: SignallerState::Stopped,
             sessions: HashMap::new(),
             codecs: BTreeMap::new(),
@@ -770,7 +771,7 @@ impl VideoEncoder {
 }
 
 impl State {
-    fn finalize_session(&mut self, session: &mut Session, signal: bool) {
+    fn finalize_session(&mut self, session: &mut Session) {
         gst::info!(CAT, "Ending session {}", session.id);
         session.pipeline.debug_to_dot_file_with_ts(
             gst::DebugGraphDetails::all(),
@@ -784,35 +785,27 @@ impl State {
         session.pipeline.call_async(|pipeline| {
             let _ = pipeline.set_state(gst::State::Null);
         });
-
-        if signal {
-            self.signaller.end_session(&session.id);
-        }
     }
 
-    fn end_session(&mut self, session_id: &str, signal: bool) -> Option<Session> {
+    fn end_session(&mut self, session_id: &str) -> Option<Session> {
         if let Some(mut session) = self.sessions.remove(session_id) {
-            self.finalize_session(&mut session, signal);
+            self.finalize_session(&mut session);
             Some(session)
         } else {
             None
         }
     }
 
-    fn maybe_start_signaller(&mut self, element: &super::WebRTCSink) {
+    fn maybe_start_signaller(
+        &mut self,
+        element: &super::WebRTCSink,
+        settings: &MutexGuard<Settings>,
+    ) {
         if self.signaller_state == SignallerState::Stopped
             && element.current_state() >= gst::State::Paused
             && self.codec_discovery_done
         {
-            self.signaller.start();
+            settings.signaller.start();
-        }
-    }
-
-    fn maybe_stop_signaller(&mut self, _element: &super::WebRTCSink) {
-        if self.signaller_state == SignallerState::Started {
-            self.signaller.stop();
-            self.signaller_state = SignallerState::Stopped;
-            gst::info!(CAT, "Stopped signaller");
         }
     }
 }
@@ -1369,13 +1362,17 @@ impl WebRTCSink {
     fn unprepare(&self, element: &super::WebRTCSink) -> Result<(), Error> {
         gst::info!(CAT, obj: element, "unpreparing");
 
+        let settings = self.settings.lock().unwrap();
+        let signaller = settings.signaller.clone();
+        drop(settings);
         let mut state = self.state.lock().unwrap();
 
         let session_ids: Vec<_> = state.sessions.keys().map(|k| k.to_owned()).collect();
 
-        for id in session_ids {
+        let sessions: Vec<_> = session_ids
-            state.end_session(&id, true);
+            .iter()
-        }
+            .filter_map(|id| state.end_session(id))
+            .collect();
 
         state
             .streams
@@ -1392,11 +1389,24 @@ impl WebRTCSink {
             });
         }
 
-        state.maybe_stop_signaller(element);
-
         state.codec_discovery_done = false;
         state.codecs = BTreeMap::new();
 
+        let signaller_state = state.signaller_state;
+        if state.signaller_state == SignallerState::Started {
+            state.signaller_state = SignallerState::Stopped;
+        }
+
+        drop(state);
+        for session in sessions {
+            signaller.end_session(&session.id);
+        }
+
+        if signaller_state == SignallerState::Started {
+            signaller.stop();
+            gst::info!(CAT, "Stopped signaller");
+        }
+
         Ok(())
     }
 
@@ -1413,6 +1423,7 @@ impl WebRTCSink {
                         gst::StreamError::Failed,
                         ["Signalling error: {}", error]
                     );
+                    false
                 })
             ),
 
@@ -1475,6 +1486,7 @@ impl WebRTCSink {
                     if let Err(err) = instance.imp().remove_session(instance, session_id, false) {
                         gst::warning!(CAT, "{}", err);
                     }
+                    false
                 })
             ),
 
@@ -1491,10 +1503,10 @@ impl WebRTCSink {
     /// When using a custom signaller
     pub fn set_signaller(&self, signaller: Signallable) -> Result<(), Error> {
         let sigobj = signaller.clone();
-        let mut state = self.state.lock().unwrap();
+        let mut settings = self.settings.lock().unwrap();
 
         self.connect_signaller(&sigobj);
-        state.signaller = signaller;
+        settings.signaller = signaller;
 
         Ok(())
     }
@@ -1522,6 +1534,7 @@ impl WebRTCSink {
         offer: gst_webrtc::WebRTCSessionDescription,
         session_id: &str,
     ) {
+        let settings = self.settings.lock().unwrap();
         let state = self.state.lock().unwrap();
 
         if let Some(session) = state.sessions.get(session_id) {
@@ -1529,7 +1542,7 @@ impl WebRTCSink {
                 .webrtcbin
                 .emit_by_name::<()>("set-local-description", &[&offer, &None::<gst::Promise>]);
 
-            state.signaller.send_sdp(session_id, &offer);
+            settings.signaller.send_sdp(session_id, &offer);
         }
     }
 
@@ -1539,6 +1552,7 @@ impl WebRTCSink {
         answer: gst_webrtc::WebRTCSessionDescription,
         session_id: &str,
     ) {
+        let settings = self.settings.lock().unwrap();
         let mut state = self.state.lock().unwrap();
 
         if let Some(mut session) = state.sessions.remove(session_id) {
@@ -1557,12 +1571,13 @@ impl WebRTCSink {
                 .webrtcbin
                 .emit_by_name::<()>("set-local-description", &[&answer, &None::<gst::Promise>]);
 
-            state.signaller.send_sdp(session_id, &answer);
+            settings.signaller.send_sdp(session_id, &answer);
             let session_id = session.id.clone();
 
             state.sessions.insert(session.id.clone(), session);
 
             drop(state);
+            drop(settings);
 
             self.on_remote_description_set(element, session_id)
         }
@@ -1872,8 +1887,8 @@ impl WebRTCSink {
         sdp_m_line_index: u32,
         candidate: String,
     ) {
-        let state = self.state.lock().unwrap();
+        let settings = self.settings.lock().unwrap();
-        state
+        settings
             .signaller
             .add_ice(&session_id, &candidate, Some(sdp_m_line_index), None)
     }
@@ -2327,12 +2342,9 @@ impl WebRTCSink {
                 // so that application code can create data channels at the correct
                 // moment.
                 element.emit_by_name::<()>("consumer-added", &[&peer_id, &webrtcbin]);
-                {
+                settings_clone
-                    let state = this.state.lock().unwrap();
-                    state
                     .signaller
                     .emit_by_name::<()>("consumer-added", &[&peer_id, &webrtcbin]);
-                }
 
                 // We don't connect to on-negotiation-needed, this in order to call the above
                 // signal without holding the state lock:
@@ -2367,17 +2379,22 @@ impl WebRTCSink {
         session_id: &str,
         signal: bool,
     ) -> Result<(), WebRTCSinkError> {
+        let settings = self.settings.lock().unwrap();
         let mut state = self.state.lock().unwrap();
 
         if !state.sessions.contains_key(session_id) {
             return Err(WebRTCSinkError::NoSessionWithId(session_id.to_string()));
         }
 
-        if let Some(session) = state.end_session(session_id, signal) {
+        if let Some(session) = state.end_session(session_id) {
-            state
+            let signaller = settings.signaller.clone();
-                .signaller
-                .emit_by_name::<()>("consumer-removed", &[&session.peer_id, &session.webrtcbin]);
             drop(state);
+            drop(settings);
+            signaller
+                .emit_by_name::<()>("consumer-removed", &[&session.peer_id, &session.webrtcbin]);
+            if signal {
+                signaller.end_session(session_id);
+            }
             element.emit_by_name::<()>("consumer-removed", &[&session.peer_id, &session.webrtcbin]);
         }
 
@@ -2524,6 +2541,7 @@ impl WebRTCSink {
 
             let element_clone = element.downgrade();
             let webrtcbin = session.webrtcbin.downgrade();
+            let session_id_clone = session_id.clone();
             RUNTIME.spawn(async move {
                 let mut interval = tokio::time::interval(std::time::Duration::from_millis(100));
 
@@ -2535,7 +2553,7 @@ impl WebRTCSink {
                     {
                         element
                             .imp()
-                            .process_stats(&element, webrtcbin, &session_id);
+                            .process_stats(&element, webrtcbin, &session_id_clone);
                     } else {
                         break;
                     }
@@ -2543,7 +2561,12 @@ impl WebRTCSink {
             });
 
             if remove {
-                state.finalize_session(&mut session, true);
+                state.finalize_session(&mut session);
+                drop(state);
+                let settings = self.settings.lock().unwrap();
+                let signaller = settings.signaller.clone();
+                drop(settings);
+                signaller.end_session(&session_id);
             } else {
                 state.sessions.insert(session.id.clone(), session);
             }
@@ -2608,7 +2631,13 @@ impl WebRTCSink {
                             media_idx,
                             media_str
                         );
-                        state.end_session(session_id, true);
+                        if let Some(_session) = state.end_session(session_id) {
+                            drop(state);
+                            let settings = self.settings.lock().unwrap();
+                            let signaller = settings.signaller.clone();
+                            drop(settings);
+                            signaller.end_session(session_id);
+                        }
 
                         gst::warning!(
                             CAT,
@@ -2634,7 +2663,13 @@ impl WebRTCSink {
                         session_id,
                     );
 
-                    state.end_session(session_id, true);
+                    if let Some(_session) = state.end_session(session_id) {
+                        drop(state);
+                        let settings = self.settings.lock().unwrap();
+                        let signaller = settings.signaller.clone();
+                        drop(settings);
+                        signaller.end_session(session_id);
+                    }
 
                     gst::warning!(CAT, obj: element, "Consumer did not provide valid payload for media sesion: {session_id} media_ix: {media_idx}");
                     return;
@@ -2948,9 +2983,10 @@ impl WebRTCSink {
                                         );
                                     }
                                     Ok(Ok(_)) => {
+                                        let settings = this.settings.lock().unwrap();
                                         let mut state = this.state.lock().unwrap();
                                         state.codec_discovery_done = true;
-                                        state.maybe_start_signaller(&element);
+                                        state.maybe_start_signaller(&element, &settings);
                                     }
                                     _ => (),
                                 }
@@ -3074,6 +3110,10 @@ impl ObjectImpl for WebRTCSink {
                     .blurb("The policy to apply for ICE transport")
                     .mutable_ready()
                     .build(),
+                glib::ParamSpecObject::builder::<Signallable>("signaller")
+                    .flags(glib::ParamFlags::READABLE  | gst::PARAM_FLAG_MUTABLE_READY)
+                    .blurb("The Signallable object to use to handle WebRTC Signalling")
+                    .build(),
             ]
         });
 
@@ -3208,6 +3248,7 @@ impl ObjectImpl for WebRTCSink {
                 let settings = self.settings.lock().unwrap();
                 settings.ice_transport_policy.to_value()
             }
+            "signaller" => self.settings.lock().unwrap().signaller.to_value(),
             _ => unimplemented!(),
         }
     }
@@ -3308,7 +3349,7 @@ impl ObjectImpl for WebRTCSink {
 
     fn constructed(&self) {
         self.parent_constructed();
-        let signaller = self.state.lock().unwrap().signaller.clone();
+        let signaller = self.settings.lock().unwrap().signaller.clone();
 
         self.connect_signaller(&signaller);
 
@@ -3466,8 +3507,9 @@ impl ElementImpl for WebRTCSink {
                 ret = Ok(gst::StateChangeSuccess::NoPreroll);
             }
             gst::StateChange::PausedToPlaying => {
+                let settings = self.settings.lock().unwrap();
                 let mut state = self.state.lock().unwrap();
-                state.maybe_start_signaller(&element);
+                state.maybe_start_signaller(&element, &settings);
             }
             _ => (),
         }
@@ -3489,7 +3531,7 @@ impl ChildProxyImpl for WebRTCSink {
 
     fn child_by_name(&self, name: &str) -> Option<glib::Object> {
         match name {
-            "signaller" => Some(self.state.lock().unwrap().signaller.clone().upcast()),
+            "signaller" => Some(self.settings.lock().unwrap().signaller.clone().upcast()),
             _ => None,
         }
     }