Merge pull request #1176 from jlehtoranta/single-player

Use a single player instance

CHANGELOG.md

@@ -36,6 +36,9 @@ https://github.com/librespot-org/librespot
 - [all] `chrono` replaced with `time` (breaking)
 - [all] `time` updated (CVE-2020-26235)
 - [all] Improve lock contention and performance (breaking)
+- [all] Use a single `player` instance. Eliminates occasional `player` and
+  `audio backend` restarts, which can cause issues with some playback
+  configurations.
 - [audio] Files are now downloaded over the HTTPS CDN (breaking)
 - [audio] Improve file opening and seeking performance (breaking)
 - [core] MSRV is now 1.65 (breaking)

connect/src/spirc.rs

@@ -3,6 +3,7 @@ use std::{
     future::Future,
     pin::Pin,
     sync::atomic::{AtomicUsize, Ordering},
+    sync::Arc,
     time::{SystemTime, UNIX_EPOCH},
 };
 
@@ -77,8 +78,8 @@ enum SpircPlayStatus {
 type BoxedStream<T> = Pin<Box<dyn FusedStream<Item = T> + Send>>;
 
 struct SpircTask {
-    player: Player,
-    mixer: Box<dyn Mixer>,
+    player: Arc<Player>,
+    mixer: Arc<dyn Mixer>,
 
     sequence: SeqGenerator<u32>,
 
@@ -272,8 +273,8 @@ impl Spirc {
         config: ConnectConfig,
         session: Session,
         credentials: Credentials,
-        player: Player,
-        mixer: Box<dyn Mixer>,
+        player: Arc<Player>,
+        mixer: Arc<dyn Mixer>,
     ) -> Result<(Spirc, impl Future<Output = ()>), Error> {
         let spirc_id = SPIRC_COUNTER.fetch_add(1, Ordering::AcqRel);
         debug!("new Spirc[{}]", spirc_id);
@@ -663,6 +664,11 @@ impl SpircTask {
     }
 
     fn handle_player_event(&mut self, event: PlayerEvent) -> Result<(), Error> {
+        // update play_request_id
+        if let PlayerEvent::PlayRequestIdChanged { play_request_id } = event {
+            self.play_request_id = Some(play_request_id);
+            return Ok(());
+        }
         // we only process events if the play_request_id matches. If it doesn't, it is
         // an event that belongs to a previous track and only arrives now due to a race
         // condition. In this case we have updated the state already and don't want to
@@ -1462,7 +1468,7 @@ impl SpircTask {
             Some((track, index)) => {
                 self.state.set_playing_track_index(index);
 
-                self.play_request_id = Some(self.player.load(track, start_playing, position_ms));
+                self.player.load(track, start_playing, position_ms);
 
                 self.update_state_position(position_ms);
                 if start_playing {

examples/play.rs

@@ -40,7 +40,7 @@ async fn main() {
         exit(1);
     }
 
-    let mut player = Player::new(player_config, session, Box::new(NoOpVolume), move || {
+    let player = Player::new(player_config, session, Box::new(NoOpVolume), move || {
         backend(None, audio_format)
     });
 

examples/play_connect.rs

@@ -17,6 +17,7 @@ use librespot_metadata::{Album, Metadata};
 use librespot_playback::mixer::{softmixer::SoftMixer, Mixer, MixerConfig};
 use librespot_protocol::spirc::TrackRef;
 use std::env;
+use std::sync::Arc;
 use tokio::join;
 
 #[tokio::main]
@@ -54,7 +55,7 @@ async fn main() {
         session.clone(),
         credentials,
         player,
-        Box::new(SoftMixer::open(MixerConfig::default())),
+        Arc::new(SoftMixer::open(MixerConfig::default())),
     )
     .await
     .unwrap();

playback/src/mixer/mod.rs

@@ -1,3 +1,5 @@
+use std::sync::Arc;
+
 use crate::config::VolumeCtrl;
 
 pub mod mappings;
@@ -5,7 +7,7 @@ use self::mappings::MappedCtrl;
 
 pub struct NoOpVolume;
 
-pub trait Mixer: Send {
+pub trait Mixer: Send + Sync {
     fn open(config: MixerConfig) -> Self
     where
         Self: Sized;
@@ -55,10 +57,10 @@ impl Default for MixerConfig {
     }
 }
 
-pub type MixerFn = fn(MixerConfig) -> Box<dyn Mixer>;
+pub type MixerFn = fn(MixerConfig) -> Arc<dyn Mixer>;
 
-fn mk_sink<M: Mixer + 'static>(config: MixerConfig) -> Box<dyn Mixer> {
-    Box::new(M::open(config))
+fn mk_sink<M: Mixer + 'static>(config: MixerConfig) -> Arc<dyn Mixer> {
+    Arc::new(M::open(config))
 }
 
 pub const MIXERS: &[(&str, MixerFn)] = &[

playback/src/player.rs

@@ -55,7 +55,6 @@ pub type PlayerResult = Result<(), Error>;
 pub struct Player {
     commands: Option<mpsc::UnboundedSender<PlayerCommand>>,
     thread_handle: Option<thread::JoinHandle<()>>,
-    play_request_id_generator: SeqGenerator<u64>,
 }
 
 #[derive(PartialEq, Eq, Debug, Clone, Copy)]
@@ -88,6 +87,7 @@ struct PlayerInternal {
     auto_normalise_as_album: bool,
 
     player_id: usize,
+    play_request_id_generator: SeqGenerator<u64>,
 }
 
 static PLAYER_COUNTER: AtomicUsize = AtomicUsize::new(0);
@@ -95,7 +95,6 @@ static PLAYER_COUNTER: AtomicUsize = AtomicUsize::new(0);
 enum PlayerCommand {
     Load {
         track_id: SpotifyId,
-        play_request_id: u64,
         play: bool,
         position_ms: u32,
     },
@@ -106,6 +105,7 @@ enum PlayerCommand {
     Pause,
     Stop,
     Seek(u32),
+    SetSession(Session),
     AddEventSender(mpsc::UnboundedSender<PlayerEvent>),
     SetSinkEventCallback(Option<SinkEventCallback>),
     EmitVolumeChangedEvent(u16),
@@ -132,6 +132,10 @@ enum PlayerCommand {
 
 #[derive(Debug, Clone)]
 pub enum PlayerEvent {
+    // Play request id changed
+    PlayRequestIdChanged {
+        play_request_id: u64,
+    },
     // Fired when the player is stopped (e.g. by issuing a "stop" command to the player).
     Stopped {
         play_request_id: u64,
@@ -416,7 +420,7 @@ impl Player {
         session: Session,
         volume_getter: Box<dyn VolumeGetter + Send>,
         sink_builder: F,
-    ) -> Self
+    ) -> Arc<Self>
     where
         F: FnOnce() -> Box<dyn Sink> + Send + 'static,
     {
@@ -475,6 +479,7 @@ impl Player {
                 auto_normalise_as_album: false,
 
                 player_id,
+                play_request_id_generator: SeqGenerator::new(0),
             };
 
             // While PlayerInternal is written as a future, it still contains blocking code.
@@ -485,11 +490,17 @@ impl Player {
             debug!("PlayerInternal thread finished.");
         });
 
-        Self {
+        Arc::new(Self {
             commands: Some(cmd_tx),
             thread_handle: Some(handle),
-            play_request_id_generator: SeqGenerator::new(0),
+        })
     }
+
+    pub fn is_invalid(&self) -> bool {
+        if let Some(handle) = self.thread_handle.as_ref() {
+            return handle.is_finished();
+        }
+        true
     }
 
     fn command(&self, cmd: PlayerCommand) {
@@ -500,16 +511,12 @@ impl Player {
         }
     }
 
-    pub fn load(&mut self, track_id: SpotifyId, start_playing: bool, position_ms: u32) -> u64 {
-        let play_request_id = self.play_request_id_generator.get();
+    pub fn load(&self, track_id: SpotifyId, start_playing: bool, position_ms: u32) {
         self.command(PlayerCommand::Load {
             track_id,
-            play_request_id,
             play: start_playing,
             position_ms,
         });
-
-        play_request_id
     }
 
     pub fn preload(&self, track_id: SpotifyId) {
@@ -532,6 +539,10 @@ impl Player {
         self.command(PlayerCommand::Seek(position_ms));
     }
 
+    pub fn set_session(&self, session: Session) {
+        self.command(PlayerCommand::SetSession(session));
+    }
+
     pub fn get_player_event_channel(&self) -> PlayerEventChannel {
         let (event_sender, event_receiver) = mpsc::unbounded_channel();
         self.command(PlayerCommand::AddEventSender(event_sender));
@@ -1379,10 +1390,6 @@ impl Future for PlayerInternal {
                 }
             }
 
-            if self.session.is_invalid() {
-                return Poll::Ready(());
-            }
-
             if (!self.state.is_playing()) && all_futures_completed_or_not_ready {
                 return Poll::Pending;
             }
@@ -1754,10 +1761,15 @@ impl PlayerInternal {
     fn handle_command_load(
         &mut self,
         track_id: SpotifyId,
-        play_request_id: u64,
+        play_request_id_option: Option<u64>,
         play: bool,
         position_ms: u32,
     ) -> PlayerResult {
+        let play_request_id =
+            play_request_id_option.unwrap_or(self.play_request_id_generator.get());
+
+        self.send_event(PlayerEvent::PlayRequestIdChanged { play_request_id });
+
         if !self.config.gapless {
             self.ensure_sink_stopped(play);
         }
@@ -2010,7 +2022,7 @@ impl PlayerInternal {
         {
             return self.handle_command_load(
                 track_id,
-                play_request_id,
+                Some(play_request_id),
                 start_playback,
                 position_ms,
             );
@@ -2067,10 +2079,9 @@ impl PlayerInternal {
         match cmd {
             PlayerCommand::Load {
                 track_id,
-                play_request_id,
                 play,
                 position_ms,
-            } => self.handle_command_load(track_id, play_request_id, play, position_ms)?,
+            } => self.handle_command_load(track_id, None, play, position_ms)?,
 
             PlayerCommand::Preload { track_id } => self.handle_command_preload(track_id),
 
@@ -2082,6 +2093,8 @@ impl PlayerInternal {
 
             PlayerCommand::Stop => self.handle_player_stop(),
 
+            PlayerCommand::SetSession(session) => self.session = session,
+
             PlayerCommand::AddEventSender(sender) => self.event_senders.push(sender),
 
             PlayerCommand::SetSinkEventCallback(callback) => self.sink_event_callback = callback,
@@ -2272,6 +2285,7 @@ impl fmt::Debug for PlayerCommand {
             PlayerCommand::Pause => f.debug_tuple("Pause").finish(),
             PlayerCommand::Stop => f.debug_tuple("Stop").finish(),
             PlayerCommand::Seek(position) => f.debug_tuple("Seek").field(&position).finish(),
+            PlayerCommand::SetSession(_) => f.debug_tuple("SetSession").finish(),
             PlayerCommand::AddEventSender(_) => f.debug_tuple("AddEventSender").finish(),
             PlayerCommand::SetSinkEventCallback(_) => {
                 f.debug_tuple("SetSinkEventCallback").finish()

src/main.rs

@@ -1715,6 +1715,31 @@ async fn main() {
         exit(1);
     }
 
+    let mixer_config = setup.mixer_config.clone();
+    let mixer = (setup.mixer)(mixer_config);
+    let player_config = setup.player_config.clone();
+
+    let soft_volume = mixer.get_soft_volume();
+    let format = setup.format;
+    let backend = setup.backend;
+    let device = setup.device.clone();
+    let player = Player::new(player_config, session.clone(), soft_volume, move || {
+        (backend)(device, format)
+    });
+
+    if let Some(player_event_program) = setup.player_event_program.clone() {
+        _event_handler = Some(EventHandler::new(
+            player.get_player_event_channel(),
+            &player_event_program,
+        ));
+
+        if setup.emit_sink_events {
+            player.set_sink_event_callback(Some(Box::new(move |sink_status| {
+                run_program_on_sink_events(sink_status, &player_event_program)
+            })));
+        }
+    }
+
     loop {
         tokio::select! {
             credentials = async {
@@ -1737,6 +1762,9 @@ async fn main() {
                             // Continue shutdown in its own task
                             tokio::spawn(spirc_task);
                         }
+                        if !session.is_invalid() {
+                            session.shutdown();
+                        }
 
                         connecting = true;
                     },
@@ -1749,32 +1777,16 @@ async fn main() {
             _ = async {}, if connecting && last_credentials.is_some() => {
                 if session.is_invalid() {
                     session = Session::new(setup.session_config.clone(), setup.cache.clone());
+                    player.set_session(session.clone());
                 }
 
-                let mixer_config = setup.mixer_config.clone();
-                let mixer = (setup.mixer)(mixer_config);
-                let player_config = setup.player_config.clone();
                 let connect_config = setup.connect_config.clone();
 
-                let soft_volume = mixer.get_soft_volume();
-                let format = setup.format;
-                let backend = setup.backend;
-                let device = setup.device.clone();
-                let player = Player::new(player_config, session.clone(), soft_volume, move || {
-                    (backend)(device, format)
-                });
-
-                if let Some(player_event_program) = setup.player_event_program.clone() {
-                    _event_handler = Some(EventHandler::new(player.get_player_event_channel(), &player_event_program));
-
-                    if setup.emit_sink_events {
-                        player.set_sink_event_callback(Some(Box::new(move |sink_status| {
-                            run_program_on_sink_events(sink_status, &player_event_program)
-                        })));
-                    }
-                };
-
-                let (spirc_, spirc_task_) = match Spirc::new(connect_config, session.clone(), last_credentials.clone().unwrap_or_default(), player, mixer).await {
+                let (spirc_, spirc_task_) = match Spirc::new(connect_config,
+                                                                session.clone(),
+                                                                last_credentials.clone().unwrap_or_default(),
+                                                                player.clone(),
+                                                                mixer.clone()).await {
                     Ok((spirc_, spirc_task_)) => (spirc_, spirc_task_),
                     Err(e) => {
                         error!("could not initialize spirc: {}", e);
@@ -1802,12 +1814,19 @@ async fn main() {
 
                 if last_credentials.is_some() && !reconnect_exceeds_rate_limit() {
                     auto_connect_times.push(Instant::now());
+                    if !session.is_invalid() {
+                        session.shutdown();
+                    }
                     connecting = true;
                 } else {
                     error!("Spirc shut down too often. Not reconnecting automatically.");
                     exit(1);
                 }
             },
+            _ = async {}, if player.is_invalid() => {
+                error!("Player shut down unexpectedly");
+                exit(1);
+            },
             _ = tokio::signal::ctrl_c() => {
                 break;
             },

src/player_event_handler.rs

@@ -21,6 +21,10 @@ impl EventHandler {
                     let mut env_vars = HashMap::new();
 
                     match event {
+                        PlayerEvent::PlayRequestIdChanged { play_request_id } => {
+                            env_vars.insert("PLAYER_EVENT", "play_request_id_changed".to_string());
+                            env_vars.insert("PLAY_REQUEST_ID", play_request_id.to_string());
+                        }
                         PlayerEvent::TrackChanged { audio_item } => {
                             match audio_item.track_id.to_base62() {
                                 Err(e) => {