peer.rs

   1use super::{
   2    Connection,
   3    message_stream::{Message, MessageStream},
   4    proto::{
   5        self, AnyTypedEnvelope, EnvelopedMessage, PeerId, Receipt, RequestMessage, TypedEnvelope,
   6    },
   7};
   8use anyhow::{Context as _, Result, anyhow};
   9use collections::HashMap;
  10use futures::{
  11    FutureExt, SinkExt, Stream, StreamExt, TryFutureExt,
  12    channel::{mpsc, oneshot},
  13    stream::BoxStream,
  14};
  15use parking_lot::{Mutex, RwLock};
  16use proto::{ErrorCode, ErrorCodeExt, ErrorExt, RpcError};
  17use serde::{Serialize, ser::SerializeStruct};
  18use std::{
  19    fmt, future,
  20    future::Future,
  21    sync::atomic::Ordering::SeqCst,
  22    sync::{
  23        Arc,
  24        atomic::{self, AtomicU32},
  25    },
  26    time::Duration,
  27    time::Instant,
  28};
  29use tracing::instrument;
  30
  31#[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash, Debug, Serialize)]
  32pub struct ConnectionId {
  33    pub owner_id: u32,
  34    pub id: u32,
  35}
  36
  37impl From<ConnectionId> for PeerId {
  38    fn from(id: ConnectionId) -> Self {
  39        PeerId {
  40            owner_id: id.owner_id,
  41            id: id.id,
  42        }
  43    }
  44}
  45
  46impl From<PeerId> for ConnectionId {
  47    fn from(peer_id: PeerId) -> Self {
  48        Self {
  49            owner_id: peer_id.owner_id,
  50            id: peer_id.id,
  51        }
  52    }
  53}
  54
  55impl fmt::Display for ConnectionId {
  56    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
  57        write!(f, "{}/{}", self.owner_id, self.id)
  58    }
  59}
  60
  61pub struct Peer {
  62    epoch: AtomicU32,
  63    pub connections: RwLock<HashMap<ConnectionId, ConnectionState>>,
  64    next_connection_id: AtomicU32,
  65}
  66
  67#[derive(Clone, Serialize)]
  68pub struct ConnectionState {
  69    #[serde(skip)]
  70    outgoing_tx: mpsc::UnboundedSender<Message>,
  71    next_message_id: Arc<AtomicU32>,
  72    #[allow(clippy::type_complexity)]
  73    #[serde(skip)]
  74    response_channels: Arc<
  75        Mutex<
  76            Option<
  77                HashMap<
  78                    u32,
  79                    oneshot::Sender<(proto::Envelope, std::time::Instant, oneshot::Sender<()>)>,
  80                >,
  81            >,
  82        >,
  83    >,
  84    #[allow(clippy::type_complexity)]
  85    #[serde(skip)]
  86    stream_response_channels: Arc<
  87        Mutex<
  88            Option<
  89                HashMap<u32, mpsc::UnboundedSender<(Result<proto::Envelope>, oneshot::Sender<()>)>>,
  90            >,
  91        >,
  92    >,
  93}
  94
  95const KEEPALIVE_INTERVAL: Duration = Duration::from_secs(1);
  96const WRITE_TIMEOUT: Duration = Duration::from_secs(2);
  97pub const RECEIVE_TIMEOUT: Duration = Duration::from_secs(10);
  98
  99impl Peer {
 100    pub fn new(epoch: u32) -> Arc<Self> {
 101        Arc::new(Self {
 102            epoch: AtomicU32::new(epoch),
 103            connections: Default::default(),
 104            next_connection_id: Default::default(),
 105        })
 106    }
 107
 108    pub fn epoch(&self) -> u32 {
 109        self.epoch.load(SeqCst)
 110    }
 111
 112    #[instrument(skip_all)]
 113    pub fn add_connection<F, Fut, Out>(
 114        self: &Arc<Self>,
 115        connection: Connection,
 116        create_timer: F,
 117    ) -> (
 118        ConnectionId,
 119        impl Future<Output = anyhow::Result<()>> + Send + use<F, Fut, Out>,
 120        BoxStream<'static, Box<dyn AnyTypedEnvelope>>,
 121    )
 122    where
 123        F: Send + Fn(Duration) -> Fut,
 124        Fut: Send + Future<Output = Out>,
 125        Out: Send,
 126    {
 127        // For outgoing messages, use an unbounded channel so that application code
 128        // can always send messages without yielding. For incoming messages, use a
 129        // bounded channel so that other peers will receive backpressure if they send
 130        // messages faster than this peer can process them.
 131        #[cfg(any(test, feature = "test-support"))]
 132        const INCOMING_BUFFER_SIZE: usize = 1;
 133        #[cfg(not(any(test, feature = "test-support")))]
 134        const INCOMING_BUFFER_SIZE: usize = 256;
 135        let (mut incoming_tx, incoming_rx) = mpsc::channel(INCOMING_BUFFER_SIZE);
 136        let (outgoing_tx, mut outgoing_rx) = mpsc::unbounded();
 137
 138        let connection_id = ConnectionId {
 139            owner_id: self.epoch.load(SeqCst),
 140            id: self.next_connection_id.fetch_add(1, SeqCst),
 141        };
 142        let connection_state = ConnectionState {
 143            outgoing_tx,
 144            next_message_id: Default::default(),
 145            response_channels: Arc::new(Mutex::new(Some(Default::default()))),
 146            stream_response_channels: Arc::new(Mutex::new(Some(Default::default()))),
 147        };
 148        let mut writer = MessageStream::new(connection.tx);
 149        let mut reader = MessageStream::new(connection.rx);
 150
 151        let this = self.clone();
 152        let response_channels = connection_state.response_channels.clone();
 153        let stream_response_channels = connection_state.stream_response_channels.clone();
 154
 155        let handle_io = async move {
 156            tracing::trace!(%connection_id, "handle io future: start");
 157
 158            let _end_connection = util::defer(|| {
 159                response_channels.lock().take();
 160                if let Some(channels) = stream_response_channels.lock().take() {
 161                    for channel in channels.values() {
 162                        let _ = channel.unbounded_send((
 163                            Err(anyhow!("connection closed")),
 164                            oneshot::channel().0,
 165                        ));
 166                    }
 167                }
 168                this.connections.write().remove(&connection_id);
 169                tracing::trace!(%connection_id, "handle io future: end");
 170            });
 171
 172            // Send messages on this frequency so the connection isn't closed.
 173            let keepalive_timer = create_timer(KEEPALIVE_INTERVAL).fuse();
 174            futures::pin_mut!(keepalive_timer);
 175
 176            // Disconnect if we don't receive messages at least this frequently.
 177            let receive_timeout = create_timer(RECEIVE_TIMEOUT).fuse();
 178            futures::pin_mut!(receive_timeout);
 179
 180            loop {
 181                tracing::trace!(%connection_id, "outer loop iteration start");
 182                let read_message = reader.read().fuse();
 183                futures::pin_mut!(read_message);
 184
 185                loop {
 186                    tracing::trace!(%connection_id, "inner loop iteration start");
 187                    futures::select_biased! {
 188                        outgoing = outgoing_rx.next().fuse() => match outgoing {
 189                            Some(outgoing) => {
 190                                tracing::trace!(%connection_id, "outgoing rpc message: writing");
 191                                futures::select_biased! {
 192                                    result = writer.write(outgoing).fuse() => {
 193                                        tracing::trace!(%connection_id, "outgoing rpc message: done writing");
 194                                        result.context("failed to write RPC message")?;
 195                                        tracing::trace!(%connection_id, "keepalive interval: resetting after sending message");
 196                                        keepalive_timer.set(create_timer(KEEPALIVE_INTERVAL).fuse());
 197                                    }
 198                                    _ = create_timer(WRITE_TIMEOUT).fuse() => {
 199                                        tracing::trace!(%connection_id, "outgoing rpc message: writing timed out");
 200                                        anyhow::bail!("timed out writing message");
 201                                    }
 202                                }
 203                            }
 204                            None => {
 205                                tracing::trace!(%connection_id, "outgoing rpc message: channel closed");
 206                                return Ok(())
 207                            },
 208                        },
 209                        _ = keepalive_timer => {
 210                            tracing::trace!(%connection_id, "keepalive interval: pinging");
 211                            futures::select_biased! {
 212                                result = writer.write(Message::Ping).fuse() => {
 213                                    tracing::trace!(%connection_id, "keepalive interval: done pinging");
 214                                    result.context("failed to send keepalive")?;
 215                                    tracing::trace!(%connection_id, "keepalive interval: resetting after pinging");
 216                                    keepalive_timer.set(create_timer(KEEPALIVE_INTERVAL).fuse());
 217                                }
 218                                _ = create_timer(WRITE_TIMEOUT).fuse() => {
 219                                    tracing::trace!(%connection_id, "keepalive interval: pinging timed out");
 220                                    anyhow::bail!("timed out sending keepalive");
 221                                }
 222                            }
 223                        }
 224                        incoming = read_message => {
 225                            let incoming = incoming.context("error reading rpc message from socket")?;
 226                            tracing::trace!(%connection_id, "incoming rpc message: received");
 227                            tracing::trace!(%connection_id, "receive timeout: resetting");
 228                            receive_timeout.set(create_timer(RECEIVE_TIMEOUT).fuse());
 229                            if let (Message::Envelope(incoming), received_at) = incoming {
 230                                tracing::trace!(%connection_id, "incoming rpc message: processing");
 231                                futures::select_biased! {
 232                                    result = incoming_tx.send((incoming, received_at)).fuse() => match result {
 233                                        Ok(_) => {
 234                                            tracing::trace!(%connection_id, "incoming rpc message: processed");
 235                                        }
 236                                        Err(_) => {
 237                                            tracing::trace!(%connection_id, "incoming rpc message: channel closed");
 238                                            return Ok(())
 239                                        }
 240                                    },
 241                                    _ = create_timer(WRITE_TIMEOUT).fuse() => {
 242                                        tracing::trace!(%connection_id, "incoming rpc message: processing timed out");
 243                                        anyhow::bail!("timed out processing incoming message");
 244                                    }
 245                                }
 246                            }
 247                            break;
 248                        },
 249                        _ = receive_timeout => {
 250                            tracing::trace!(%connection_id, "receive timeout: delay between messages too long");
 251                            anyhow::bail!("delay between messages too long");
 252                        }
 253                    }
 254                }
 255            }
 256        };
 257
 258        let response_channels = connection_state.response_channels.clone();
 259        let stream_response_channels = connection_state.stream_response_channels.clone();
 260        self.connections
 261            .write()
 262            .insert(connection_id, connection_state);
 263
 264        let incoming_rx = incoming_rx.filter_map(move |(incoming, received_at)| {
 265            let response_channels = response_channels.clone();
 266            let stream_response_channels = stream_response_channels.clone();
 267            async move {
 268                let message_id = incoming.id;
 269                tracing::trace!(?incoming, "incoming message future: start");
 270                let _end = util::defer(move || {
 271                    tracing::trace!(%connection_id, message_id, "incoming message future: end");
 272                });
 273
 274                if let Some(responding_to) = incoming.responding_to {
 275                    tracing::trace!(
 276                        %connection_id,
 277                        message_id,
 278                        responding_to,
 279                        "incoming response: received"
 280                    );
 281                    let response_channel =
 282                        response_channels.lock().as_mut()?.remove(&responding_to);
 283                    let stream_response_channel = stream_response_channels
 284                        .lock()
 285                        .as_ref()?
 286                        .get(&responding_to)
 287                        .cloned();
 288
 289                    if let Some(tx) = response_channel {
 290                        let requester_resumed = oneshot::channel();
 291                        if let Err(error) = tx.send((incoming, received_at, requester_resumed.0)) {
 292                            tracing::trace!(
 293                                %connection_id,
 294                                message_id,
 295                                responding_to = responding_to,
 296                                ?error,
 297                                "incoming response: request future dropped",
 298                            );
 299                        }
 300
 301                        tracing::trace!(
 302                            %connection_id,
 303                            message_id,
 304                            responding_to,
 305                            "incoming response: waiting to resume requester"
 306                        );
 307                        let _ = requester_resumed.1.await;
 308                        tracing::trace!(
 309                            %connection_id,
 310                            message_id,
 311                            responding_to,
 312                            "incoming response: requester resumed"
 313                        );
 314                    } else if let Some(tx) = stream_response_channel {
 315                        let requester_resumed = oneshot::channel();
 316                        if let Err(error) = tx.unbounded_send((Ok(incoming), requester_resumed.0)) {
 317                            tracing::debug!(
 318                                %connection_id,
 319                                message_id,
 320                                responding_to = responding_to,
 321                                ?error,
 322                                "incoming stream response: request future dropped",
 323                            );
 324                        }
 325
 326                        tracing::debug!(
 327                            %connection_id,
 328                            message_id,
 329                            responding_to,
 330                            "incoming stream response: waiting to resume requester"
 331                        );
 332                        let _ = requester_resumed.1.await;
 333                        tracing::debug!(
 334                            %connection_id,
 335                            message_id,
 336                            responding_to,
 337                            "incoming stream response: requester resumed"
 338                        );
 339                    } else {
 340                        let message_type = proto::build_typed_envelope(
 341                            connection_id.into(),
 342                            received_at,
 343                            incoming,
 344                        )
 345                        .map(|p| p.payload_type_name());
 346                        tracing::warn!(
 347                            %connection_id,
 348                            message_id,
 349                            responding_to,
 350                            message_type,
 351                            "incoming response: unknown request"
 352                        );
 353                    }
 354
 355                    None
 356                } else {
 357                    tracing::trace!(%connection_id, message_id, "incoming message: received");
 358                    proto::build_typed_envelope(connection_id.into(), received_at, incoming)
 359                        .or_else(|| {
 360                            tracing::error!(
 361                                %connection_id,
 362                                message_id,
 363                                "unable to construct a typed envelope"
 364                            );
 365                            None
 366                        })
 367                }
 368            }
 369        });
 370        (connection_id, handle_io, incoming_rx.boxed())
 371    }
 372
 373    #[cfg(any(test, feature = "test-support"))]
 374    pub fn add_test_connection(
 375        self: &Arc<Self>,
 376        connection: Connection,
 377        executor: gpui::BackgroundExecutor,
 378    ) -> (
 379        ConnectionId,
 380        impl Future<Output = anyhow::Result<()>> + Send + use<>,
 381        BoxStream<'static, Box<dyn AnyTypedEnvelope>>,
 382    ) {
 383        let executor = executor.clone();
 384        self.add_connection(connection, move |duration| executor.timer(duration))
 385    }
 386
 387    pub fn disconnect(&self, connection_id: ConnectionId) {
 388        self.connections.write().remove(&connection_id);
 389    }
 390
 391    #[cfg(any(test, feature = "test-support"))]
 392    pub fn reset(&self, epoch: u32) {
 393        self.next_connection_id.store(0, SeqCst);
 394        self.epoch.store(epoch, SeqCst);
 395    }
 396
 397    pub fn teardown(&self) {
 398        self.connections.write().clear();
 399    }
 400
 401    /// Make a request and wait for a response.
 402    pub fn request<T: RequestMessage>(
 403        &self,
 404        receiver_id: ConnectionId,
 405        request: T,
 406    ) -> impl Future<Output = Result<T::Response>> + use<T> {
 407        self.request_internal(None, receiver_id, request)
 408            .map_ok(|envelope| envelope.payload)
 409    }
 410
 411    pub fn request_envelope<T: RequestMessage>(
 412        &self,
 413        receiver_id: ConnectionId,
 414        request: T,
 415    ) -> impl Future<Output = Result<TypedEnvelope<T::Response>>> + use<T> {
 416        self.request_internal(None, receiver_id, request)
 417    }
 418
 419    pub fn forward_request<T: RequestMessage>(
 420        &self,
 421        sender_id: ConnectionId,
 422        receiver_id: ConnectionId,
 423        request: T,
 424    ) -> impl Future<Output = Result<T::Response>> {
 425        self.request_internal(Some(sender_id), receiver_id, request)
 426            .map_ok(|envelope| envelope.payload)
 427    }
 428
 429    fn request_internal<T: RequestMessage>(
 430        &self,
 431        original_sender_id: Option<ConnectionId>,
 432        receiver_id: ConnectionId,
 433        request: T,
 434    ) -> impl Future<Output = Result<TypedEnvelope<T::Response>>> + use<T> {
 435        let envelope = request.into_envelope(0, None, original_sender_id.map(Into::into));
 436        let response = self.request_dynamic(receiver_id, envelope, T::NAME);
 437        async move {
 438            let (response, received_at) = response.await?;
 439            Ok(TypedEnvelope {
 440                message_id: response.id,
 441                sender_id: receiver_id.into(),
 442                original_sender_id: response.original_sender_id,
 443                payload: T::Response::from_envelope(response)
 444                    .context("received response of the wrong type")?,
 445                received_at,
 446            })
 447        }
 448    }
 449
 450    /// Make a request and wait for a response.
 451    ///
 452    /// The caller must make sure to deserialize the response into the request's
 453    /// response type. This interface is only useful in trait objects, where
 454    /// generics can't be used. If you have a concrete type, use `request`.
 455    pub fn request_dynamic(
 456        &self,
 457        receiver_id: ConnectionId,
 458        mut envelope: proto::Envelope,
 459        type_name: &'static str,
 460    ) -> impl Future<Output = Result<(proto::Envelope, Instant)>> + use<> {
 461        let (tx, rx) = oneshot::channel();
 462        let send = self.connection_state(receiver_id).and_then(|connection| {
 463            envelope.id = connection.next_message_id.fetch_add(1, SeqCst);
 464            connection
 465                .response_channels
 466                .lock()
 467                .as_mut()
 468                .context("connection was closed")?
 469                .insert(envelope.id, tx);
 470            connection
 471                .outgoing_tx
 472                .unbounded_send(Message::Envelope(envelope))
 473                .context("connection was closed")?;
 474            Ok(())
 475        });
 476        async move {
 477            send?;
 478            let (response, received_at, _barrier) = rx.await.context("connection was closed")?;
 479            if let Some(proto::envelope::Payload::Error(error)) = &response.payload {
 480                return Err(RpcError::from_proto(error, type_name));
 481            }
 482            Ok((response, received_at))
 483        }
 484    }
 485
 486    pub fn request_stream<T: RequestMessage>(
 487        &self,
 488        receiver_id: ConnectionId,
 489        request: T,
 490    ) -> impl Future<Output = Result<impl Unpin + Stream<Item = Result<T::Response>>>> {
 491        let (tx, rx) = mpsc::unbounded();
 492        let send = self.connection_state(receiver_id).and_then(|connection| {
 493            let message_id = connection.next_message_id.fetch_add(1, SeqCst);
 494            let stream_response_channels = connection.stream_response_channels.clone();
 495            stream_response_channels
 496                .lock()
 497                .as_mut()
 498                .context("connection was closed")?
 499                .insert(message_id, tx);
 500            connection
 501                .outgoing_tx
 502                .unbounded_send(Message::Envelope(
 503                    request.into_envelope(message_id, None, None),
 504                ))
 505                .context("connection was closed")?;
 506            Ok((message_id, stream_response_channels))
 507        });
 508
 509        async move {
 510            let (message_id, stream_response_channels) = send?;
 511            let stream_response_channels = Arc::downgrade(&stream_response_channels);
 512
 513            Ok(rx.filter_map(move |(response, _barrier)| {
 514                let stream_response_channels = stream_response_channels.clone();
 515                future::ready(match response {
 516                    Ok(response) => {
 517                        if let Some(proto::envelope::Payload::Error(error)) = &response.payload {
 518                            Some(Err(RpcError::from_proto(error, T::NAME)))
 519                        } else if let Some(proto::envelope::Payload::EndStream(_)) =
 520                            &response.payload
 521                        {
 522                            // Remove the transmitting end of the response channel to end the stream.
 523                            if let Some(channels) = stream_response_channels.upgrade()
 524                                && let Some(channels) = channels.lock().as_mut() {
 525                                    channels.remove(&message_id);
 526                                }
 527                            None
 528                        } else {
 529                            Some(
 530                                T::Response::from_envelope(response)
 531                                    .context("received response of the wrong type"),
 532                            )
 533                        }
 534                    }
 535                    Err(error) => Some(Err(error)),
 536                })
 537            }))
 538        }
 539    }
 540
 541    pub fn send<T: EnvelopedMessage>(&self, receiver_id: ConnectionId, message: T) -> Result<()> {
 542        let connection = self.connection_state(receiver_id)?;
 543        let message_id = connection
 544            .next_message_id
 545            .fetch_add(1, atomic::Ordering::SeqCst);
 546        connection.outgoing_tx.unbounded_send(Message::Envelope(
 547            message.into_envelope(message_id, None, None),
 548        ))?;
 549        Ok(())
 550    }
 551
 552    pub fn send_dynamic(&self, receiver_id: ConnectionId, message: proto::Envelope) -> Result<()> {
 553        let connection = self.connection_state(receiver_id)?;
 554        connection
 555            .outgoing_tx
 556            .unbounded_send(Message::Envelope(message))?;
 557        Ok(())
 558    }
 559
 560    pub fn forward_send<T: EnvelopedMessage>(
 561        &self,
 562        sender_id: ConnectionId,
 563        receiver_id: ConnectionId,
 564        message: T,
 565    ) -> Result<()> {
 566        let connection = self.connection_state(receiver_id)?;
 567        let message_id = connection
 568            .next_message_id
 569            .fetch_add(1, atomic::Ordering::SeqCst);
 570        connection
 571            .outgoing_tx
 572            .unbounded_send(Message::Envelope(message.into_envelope(
 573                message_id,
 574                None,
 575                Some(sender_id.into()),
 576            )))?;
 577        Ok(())
 578    }
 579
 580    pub fn respond<T: RequestMessage>(
 581        &self,
 582        receipt: Receipt<T>,
 583        response: T::Response,
 584    ) -> Result<()> {
 585        let connection = self.connection_state(receipt.sender_id.into())?;
 586        let message_id = connection
 587            .next_message_id
 588            .fetch_add(1, atomic::Ordering::SeqCst);
 589        connection
 590            .outgoing_tx
 591            .unbounded_send(Message::Envelope(response.into_envelope(
 592                message_id,
 593                Some(receipt.message_id),
 594                None,
 595            )))?;
 596        Ok(())
 597    }
 598
 599    pub fn end_stream<T: RequestMessage>(&self, receipt: Receipt<T>) -> Result<()> {
 600        let connection = self.connection_state(receipt.sender_id.into())?;
 601        let message_id = connection
 602            .next_message_id
 603            .fetch_add(1, atomic::Ordering::SeqCst);
 604
 605        let message = proto::EndStream {};
 606
 607        connection
 608            .outgoing_tx
 609            .unbounded_send(Message::Envelope(message.into_envelope(
 610                message_id,
 611                Some(receipt.message_id),
 612                None,
 613            )))?;
 614        Ok(())
 615    }
 616
 617    pub fn respond_with_error<T: RequestMessage>(
 618        &self,
 619        receipt: Receipt<T>,
 620        response: proto::Error,
 621    ) -> Result<()> {
 622        let connection = self.connection_state(receipt.sender_id.into())?;
 623        let message_id = connection
 624            .next_message_id
 625            .fetch_add(1, atomic::Ordering::SeqCst);
 626        connection
 627            .outgoing_tx
 628            .unbounded_send(Message::Envelope(response.into_envelope(
 629                message_id,
 630                Some(receipt.message_id),
 631                None,
 632            )))?;
 633        Ok(())
 634    }
 635
 636    pub fn respond_with_unhandled_message(
 637        &self,
 638        sender_id: ConnectionId,
 639        request_message_id: u32,
 640        message_type_name: &'static str,
 641    ) -> Result<()> {
 642        let connection = self.connection_state(sender_id)?;
 643        let response = ErrorCode::Internal
 644            .message(format!("message {} was not handled", message_type_name))
 645            .to_proto();
 646        let message_id = connection
 647            .next_message_id
 648            .fetch_add(1, atomic::Ordering::SeqCst);
 649        connection
 650            .outgoing_tx
 651            .unbounded_send(Message::Envelope(response.into_envelope(
 652                message_id,
 653                Some(request_message_id),
 654                None,
 655            )))?;
 656        Ok(())
 657    }
 658
 659    fn connection_state(&self, connection_id: ConnectionId) -> Result<ConnectionState> {
 660        let connections = self.connections.read();
 661        let connection = connections
 662            .get(&connection_id)
 663            .with_context(|| format!("no such connection: {connection_id}"))?;
 664        Ok(connection.clone())
 665    }
 666}
 667
 668impl Serialize for Peer {
 669    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
 670    where
 671        S: serde::Serializer,
 672    {
 673        let mut state = serializer.serialize_struct("Peer", 2)?;
 674        state.serialize_field("connections", &*self.connections.read())?;
 675        state.end()
 676    }
 677}
 678
 679#[cfg(test)]
 680mod tests {
 681    use super::*;
 682    use async_tungstenite::tungstenite::Message as WebSocketMessage;
 683    use gpui::TestAppContext;
 684
 685    fn init_logger() {
 686        zlog::init_test();
 687    }
 688
 689    #[gpui::test(iterations = 50)]
 690    async fn test_request_response(cx: &mut TestAppContext) {
 691        init_logger();
 692
 693        let executor = cx.executor();
 694
 695        // create 2 clients connected to 1 server
 696        let server = Peer::new(0);
 697        let client1 = Peer::new(0);
 698        let client2 = Peer::new(0);
 699
 700        let (client1_to_server_conn, server_to_client_1_conn, _kill) =
 701            Connection::in_memory(cx.executor());
 702        let (client1_conn_id, io_task1, client1_incoming) =
 703            client1.add_test_connection(client1_to_server_conn, cx.executor());
 704        let (_, io_task2, server_incoming1) =
 705            server.add_test_connection(server_to_client_1_conn, cx.executor());
 706
 707        let (client2_to_server_conn, server_to_client_2_conn, _kill) =
 708            Connection::in_memory(cx.executor());
 709        let (client2_conn_id, io_task3, client2_incoming) =
 710            client2.add_test_connection(client2_to_server_conn, cx.executor());
 711        let (_, io_task4, server_incoming2) =
 712            server.add_test_connection(server_to_client_2_conn, cx.executor());
 713
 714        executor.spawn(io_task1).detach();
 715        executor.spawn(io_task2).detach();
 716        executor.spawn(io_task3).detach();
 717        executor.spawn(io_task4).detach();
 718        executor
 719            .spawn(handle_messages(server_incoming1, server.clone()))
 720            .detach();
 721        executor
 722            .spawn(handle_messages(client1_incoming, client1.clone()))
 723            .detach();
 724        executor
 725            .spawn(handle_messages(server_incoming2, server.clone()))
 726            .detach();
 727        executor
 728            .spawn(handle_messages(client2_incoming, client2.clone()))
 729            .detach();
 730
 731        assert_eq!(
 732            client1
 733                .request(client1_conn_id, proto::Ping {},)
 734                .await
 735                .unwrap(),
 736            proto::Ack {}
 737        );
 738
 739        assert_eq!(
 740            client2
 741                .request(client2_conn_id, proto::Ping {},)
 742                .await
 743                .unwrap(),
 744            proto::Ack {}
 745        );
 746
 747        assert_eq!(
 748            client1
 749                .request(client1_conn_id, proto::Test { id: 1 },)
 750                .await
 751                .unwrap(),
 752            proto::Test { id: 1 }
 753        );
 754
 755        assert_eq!(
 756            client2
 757                .request(client2_conn_id, proto::Test { id: 2 })
 758                .await
 759                .unwrap(),
 760            proto::Test { id: 2 }
 761        );
 762
 763        client1.disconnect(client1_conn_id);
 764        client2.disconnect(client1_conn_id);
 765
 766        async fn handle_messages(
 767            mut messages: BoxStream<'static, Box<dyn AnyTypedEnvelope>>,
 768            peer: Arc<Peer>,
 769        ) -> Result<()> {
 770            while let Some(envelope) = messages.next().await {
 771                let envelope = envelope.into_any();
 772                if let Some(envelope) = envelope.downcast_ref::<TypedEnvelope<proto::Ping>>() {
 773                    let receipt = envelope.receipt();
 774                    peer.respond(receipt, proto::Ack {})?
 775                } else if let Some(envelope) = envelope.downcast_ref::<TypedEnvelope<proto::Test>>()
 776                {
 777                    peer.respond(envelope.receipt(), envelope.payload.clone())?
 778                } else {
 779                    panic!("unknown message type");
 780                }
 781            }
 782
 783            Ok(())
 784        }
 785    }
 786
 787    #[gpui::test(iterations = 50)]
 788    async fn test_order_of_response_and_incoming(cx: &mut TestAppContext) {
 789        let executor = cx.executor();
 790        let server = Peer::new(0);
 791        let client = Peer::new(0);
 792
 793        let (client_to_server_conn, server_to_client_conn, _kill) =
 794            Connection::in_memory(executor.clone());
 795        let (client_to_server_conn_id, io_task1, mut client_incoming) =
 796            client.add_test_connection(client_to_server_conn, executor.clone());
 797
 798        let (server_to_client_conn_id, io_task2, mut server_incoming) =
 799            server.add_test_connection(server_to_client_conn, executor.clone());
 800
 801        executor.spawn(io_task1).detach();
 802        executor.spawn(io_task2).detach();
 803
 804        executor
 805            .spawn(async move {
 806                let future = server_incoming.next().await;
 807                let request = future
 808                    .unwrap()
 809                    .into_any()
 810                    .downcast::<TypedEnvelope<proto::Ping>>()
 811                    .unwrap();
 812
 813                server
 814                    .send(
 815                        server_to_client_conn_id,
 816                        ErrorCode::Internal
 817                            .message("message 1".to_string())
 818                            .to_proto(),
 819                    )
 820                    .unwrap();
 821                server
 822                    .send(
 823                        server_to_client_conn_id,
 824                        ErrorCode::Internal
 825                            .message("message 2".to_string())
 826                            .to_proto(),
 827                    )
 828                    .unwrap();
 829                server.respond(request.receipt(), proto::Ack {}).unwrap();
 830
 831                // Prevent the connection from being dropped
 832                server_incoming.next().await;
 833            })
 834            .detach();
 835
 836        let events = Arc::new(Mutex::new(Vec::new()));
 837
 838        let response = client.request(client_to_server_conn_id, proto::Ping {});
 839        let response_task = executor.spawn({
 840            let events = events.clone();
 841            async move {
 842                response.await.unwrap();
 843                events.lock().push("response".to_string());
 844            }
 845        });
 846
 847        executor
 848            .spawn({
 849                let events = events.clone();
 850                async move {
 851                    let incoming1 = client_incoming
 852                        .next()
 853                        .await
 854                        .unwrap()
 855                        .into_any()
 856                        .downcast::<TypedEnvelope<proto::Error>>()
 857                        .unwrap();
 858                    events.lock().push(incoming1.payload.message);
 859                    let incoming2 = client_incoming
 860                        .next()
 861                        .await
 862                        .unwrap()
 863                        .into_any()
 864                        .downcast::<TypedEnvelope<proto::Error>>()
 865                        .unwrap();
 866                    events.lock().push(incoming2.payload.message);
 867
 868                    // Prevent the connection from being dropped
 869                    client_incoming.next().await;
 870                }
 871            })
 872            .detach();
 873
 874        response_task.await;
 875        assert_eq!(
 876            &*events.lock(),
 877            &[
 878                "message 1".to_string(),
 879                "message 2".to_string(),
 880                "response".to_string()
 881            ]
 882        );
 883    }
 884
 885    #[gpui::test(iterations = 50)]
 886    async fn test_dropping_request_before_completion(cx: &mut TestAppContext) {
 887        let executor = cx.executor();
 888        let server = Peer::new(0);
 889        let client = Peer::new(0);
 890
 891        let (client_to_server_conn, server_to_client_conn, _kill) =
 892            Connection::in_memory(cx.executor());
 893        let (client_to_server_conn_id, io_task1, mut client_incoming) =
 894            client.add_test_connection(client_to_server_conn, cx.executor());
 895        let (server_to_client_conn_id, io_task2, mut server_incoming) =
 896            server.add_test_connection(server_to_client_conn, cx.executor());
 897
 898        executor.spawn(io_task1).detach();
 899        executor.spawn(io_task2).detach();
 900
 901        executor
 902            .spawn(async move {
 903                let request1 = server_incoming
 904                    .next()
 905                    .await
 906                    .unwrap()
 907                    .into_any()
 908                    .downcast::<TypedEnvelope<proto::Ping>>()
 909                    .unwrap();
 910                let request2 = server_incoming
 911                    .next()
 912                    .await
 913                    .unwrap()
 914                    .into_any()
 915                    .downcast::<TypedEnvelope<proto::Ping>>()
 916                    .unwrap();
 917
 918                server
 919                    .send(
 920                        server_to_client_conn_id,
 921                        ErrorCode::Internal
 922                            .message("message 1".to_string())
 923                            .to_proto(),
 924                    )
 925                    .unwrap();
 926                server
 927                    .send(
 928                        server_to_client_conn_id,
 929                        ErrorCode::Internal
 930                            .message("message 2".to_string())
 931                            .to_proto(),
 932                    )
 933                    .unwrap();
 934                server.respond(request1.receipt(), proto::Ack {}).unwrap();
 935                server.respond(request2.receipt(), proto::Ack {}).unwrap();
 936
 937                // Prevent the connection from being dropped
 938                server_incoming.next().await;
 939            })
 940            .detach();
 941
 942        let events = Arc::new(Mutex::new(Vec::new()));
 943
 944        let request1 = client.request(client_to_server_conn_id, proto::Ping {});
 945        let request1_task = executor.spawn(request1);
 946        let request2 = client.request(client_to_server_conn_id, proto::Ping {});
 947        let request2_task = executor.spawn({
 948            let events = events.clone();
 949            async move {
 950                request2.await.unwrap();
 951                events.lock().push("response 2".to_string());
 952            }
 953        });
 954
 955        executor
 956            .spawn({
 957                let events = events.clone();
 958                async move {
 959                    let incoming1 = client_incoming
 960                        .next()
 961                        .await
 962                        .unwrap()
 963                        .into_any()
 964                        .downcast::<TypedEnvelope<proto::Error>>()
 965                        .unwrap();
 966                    events.lock().push(incoming1.payload.message);
 967                    let incoming2 = client_incoming
 968                        .next()
 969                        .await
 970                        .unwrap()
 971                        .into_any()
 972                        .downcast::<TypedEnvelope<proto::Error>>()
 973                        .unwrap();
 974                    events.lock().push(incoming2.payload.message);
 975
 976                    // Prevent the connection from being dropped
 977                    client_incoming.next().await;
 978                }
 979            })
 980            .detach();
 981
 982        // Allow the request to make some progress before dropping it.
 983        cx.executor().simulate_random_delay().await;
 984        drop(request1_task);
 985
 986        request2_task.await;
 987        assert_eq!(
 988            &*events.lock(),
 989            &[
 990                "message 1".to_string(),
 991                "message 2".to_string(),
 992                "response 2".to_string()
 993            ]
 994        );
 995    }
 996
 997    #[gpui::test(iterations = 50)]
 998    async fn test_disconnect(cx: &mut TestAppContext) {
 999        let executor = cx.executor();
1000
1001        let (client_conn, mut server_conn, _kill) = Connection::in_memory(executor.clone());
1002
1003        let client = Peer::new(0);
1004        let (connection_id, io_handler, mut incoming) =
1005            client.add_test_connection(client_conn, executor.clone());
1006
1007        let (io_ended_tx, io_ended_rx) = oneshot::channel();
1008        executor
1009            .spawn(async move {
1010                io_handler.await.ok();
1011                io_ended_tx.send(()).unwrap();
1012            })
1013            .detach();
1014
1015        let (messages_ended_tx, messages_ended_rx) = oneshot::channel();
1016        executor
1017            .spawn(async move {
1018                incoming.next().await;
1019                messages_ended_tx.send(()).unwrap();
1020            })
1021            .detach();
1022
1023        client.disconnect(connection_id);
1024
1025        let _ = io_ended_rx.await;
1026        let _ = messages_ended_rx.await;
1027        assert!(
1028            server_conn
1029                .send(WebSocketMessage::Binary(vec![].into()))
1030                .await
1031                .is_err()
1032        );
1033    }
1034
1035    #[gpui::test(iterations = 50)]
1036    async fn test_io_error(cx: &mut TestAppContext) {
1037        let executor = cx.executor();
1038        let (client_conn, mut server_conn, _kill) = Connection::in_memory(executor.clone());
1039
1040        let client = Peer::new(0);
1041        let (connection_id, io_handler, mut incoming) =
1042            client.add_test_connection(client_conn, executor.clone());
1043        executor.spawn(io_handler).detach();
1044        executor
1045            .spawn(async move { incoming.next().await })
1046            .detach();
1047
1048        let response = executor.spawn(client.request(connection_id, proto::Ping {}));
1049        let _request = server_conn.rx.next().await.unwrap().unwrap();
1050
1051        drop(server_conn);
1052        assert_eq!(
1053            response.await.unwrap_err().to_string(),
1054            "connection was closed"
1055        );
1056    }
1057}