Preserve the order of responses with respect to all other incoming messages

Antonio Scandurra , Nathan Sobo , and Max Brunsfeld created

Co-Authored-By: Nathan Sobo <nathan@zed.dev>
Co-Authored-By: Max Brunsfeld <max@zed.dev>

Change summary

crates/client/src/client.rs    | 23 +++++++-------
crates/client/src/test.rs      |  7 +--
crates/project/src/worktree.rs |  2 -
crates/rpc/src/peer.rs         | 55 ++++++++++++++++++++++-------------
crates/server/src/rpc.rs       | 16 +++++-----
5 files changed, 57 insertions(+), 46 deletions(-)

Detailed changes

crates/client/src/client.rs 🔗

@@ -11,11 +11,12 @@ use async_tungstenite::tungstenite::{
     error::Error as WebsocketError,
     http::{Request, StatusCode},
 };
+use futures::StreamExt;
 use gpui::{action, AsyncAppContext, Entity, ModelContext, MutableAppContext, Task};
 use http::HttpClient;
 use lazy_static::lazy_static;
 use parking_lot::RwLock;
-use postage::{prelude::Stream, watch};
+use postage::watch;
 use rand::prelude::*;
 use rpc::proto::{AnyTypedEnvelope, EntityMessage, EnvelopedMessage, RequestMessage};
 use std::{
@@ -436,7 +437,7 @@ impl Client {
                 let mut cx = cx.clone();
                 let this = self.clone();
                 async move {
-                    while let Some(message) = incoming.recv().await {
+                    while let Some(message) = incoming.next().await {
                         let mut state = this.state.write();
                         let payload_type_id = message.payload_type_id();
                         let entity_id = if let Some(extract_entity_id) =
@@ -777,23 +778,23 @@ mod tests {
         let server = FakeServer::for_client(user_id, &mut client, &cx).await;
         let mut status = client.status();
         assert!(matches!(
-            status.recv().await,
+            status.next().await,
             Some(Status::Connected { .. })
         ));
         assert_eq!(server.auth_count(), 1);
 
         server.forbid_connections();
         server.disconnect();
-        while !matches!(status.recv().await, Some(Status::ReconnectionError { .. })) {}
+        while !matches!(status.next().await, Some(Status::ReconnectionError { .. })) {}
 
         server.allow_connections();
         cx.foreground().advance_clock(Duration::from_secs(10));
-        while !matches!(status.recv().await, Some(Status::Connected { .. })) {}
+        while !matches!(status.next().await, Some(Status::Connected { .. })) {}
         assert_eq!(server.auth_count(), 1); // Client reused the cached credentials when reconnecting
 
         server.forbid_connections();
         server.disconnect();
-        while !matches!(status.recv().await, Some(Status::ReconnectionError { .. })) {}
+        while !matches!(status.next().await, Some(Status::ReconnectionError { .. })) {}
 
         // Clear cached credentials after authentication fails
         server.roll_access_token();
@@ -801,7 +802,7 @@ mod tests {
         cx.foreground().advance_clock(Duration::from_secs(10));
         assert_eq!(server.auth_count(), 1);
         cx.foreground().advance_clock(Duration::from_secs(10));
-        while !matches!(status.recv().await, Some(Status::Connected { .. })) {}
+        while !matches!(status.next().await, Some(Status::Connected { .. })) {}
         assert_eq!(server.auth_count(), 2); // Client re-authenticated due to an invalid token
     }
 
@@ -861,8 +862,8 @@ mod tests {
 
         server.send(proto::UnshareProject { project_id: 1 }).await;
         server.send(proto::UnshareProject { project_id: 2 }).await;
-        done_rx1.recv().await.unwrap();
-        done_rx2.recv().await.unwrap();
+        done_rx1.next().await.unwrap();
+        done_rx2.next().await.unwrap();
     }
 
     #[gpui::test]
@@ -890,7 +891,7 @@ mod tests {
             })
         });
         server.send(proto::Ping {}).await;
-        done_rx2.recv().await.unwrap();
+        done_rx2.next().await.unwrap();
     }
 
     #[gpui::test]
@@ -914,7 +915,7 @@ mod tests {
             ));
         });
         server.send(proto::Ping {}).await;
-        done_rx.recv().await.unwrap();
+        done_rx.next().await.unwrap();
     }
 
     struct Model {

crates/client/src/test.rs 🔗

@@ -1,10 +1,9 @@
 use super::Client;
 use super::*;
 use crate::http::{HttpClient, Request, Response, ServerResponse};
-use futures::{future::BoxFuture, Future};
+use futures::{future::BoxFuture, stream::BoxStream, Future, StreamExt};
 use gpui::{ModelHandle, TestAppContext};
 use parking_lot::Mutex;
-use postage::{mpsc, prelude::Stream};
 use rpc::{proto, ConnectionId, Peer, Receipt, TypedEnvelope};
 use std::fmt;
 use std::sync::atomic::Ordering::SeqCst;
@@ -15,7 +14,7 @@ use std::sync::{
 
 pub struct FakeServer {
     peer: Arc<Peer>,
-    incoming: Mutex<Option<mpsc::Receiver<Box<dyn proto::AnyTypedEnvelope>>>>,
+    incoming: Mutex<Option<BoxStream<'static, Box<dyn proto::AnyTypedEnvelope>>>>,
     connection_id: Mutex<Option<ConnectionId>>,
     forbid_connections: AtomicBool,
     auth_count: AtomicUsize,
@@ -129,7 +128,7 @@ impl FakeServer {
             .lock()
             .as_mut()
             .expect("not connected")
-            .recv()
+            .next()
             .await
             .ok_or_else(|| anyhow!("other half hung up"))?;
         let type_name = message.payload_type_name();

crates/project/src/worktree.rs 🔗

@@ -600,7 +600,6 @@ impl Worktree {
             // We spawn here in order to enqueue the sending of `Ack` *after* transmission of edits
             // associated with formatting.
             cx.spawn(|_| async move {
-                dbg!("responding");
                 match format {
                     Ok(()) => rpc.respond(receipt, proto::Ack {}).await?,
                     Err(error) => {
@@ -923,7 +922,6 @@ impl Worktree {
             )),
         } {
             cx.spawn(|worktree, mut cx| async move {
-                dbg!(&operation);
                 if let Err(error) = rpc
                     .request(proto::UpdateBuffer {
                         project_id,

crates/rpc/src/peer.rs 🔗

@@ -1,7 +1,8 @@
 use super::proto::{self, AnyTypedEnvelope, EnvelopedMessage, MessageStream, RequestMessage};
 use super::Connection;
 use anyhow::{anyhow, Context, Result};
-use futures::FutureExt as _;
+use futures::stream::BoxStream;
+use futures::{FutureExt as _, StreamExt};
 use parking_lot::{Mutex, RwLock};
 use postage::{
     mpsc,
@@ -109,7 +110,7 @@ impl Peer {
     ) -> (
         ConnectionId,
         impl Future<Output = anyhow::Result<()>> + Send,
-        mpsc::Receiver<Box<dyn AnyTypedEnvelope>>,
+        BoxStream<'static, Box<dyn AnyTypedEnvelope>>,
     ) {
         let connection_id = ConnectionId(self.next_connection_id.fetch_add(1, SeqCst));
         let (mut incoming_tx, incoming_rx) = mpsc::channel(64);
@@ -132,23 +133,9 @@ impl Peer {
                     futures::select_biased! {
                         incoming = read_message => match incoming {
                             Ok(incoming) => {
-                                if let Some(responding_to) = incoming.responding_to {
-                                    let channel = response_channels.lock().as_mut().unwrap().remove(&responding_to);
-                                    if let Some(mut tx) = channel {
-                                        tx.send(incoming).await.ok();
-                                    } else {
-                                        log::warn!("received RPC response to unknown request {}", responding_to);
-                                    }
-                                } else {
-                                    if let Some(envelope) = proto::build_typed_envelope(connection_id, incoming) {
-                                        if incoming_tx.send(envelope).await.is_err() {
-                                            break 'outer Ok(())
-                                        }
-                                    } else {
-                                        log::error!("unable to construct a typed envelope");
-                                    }
+                                if incoming_tx.send(incoming).await.is_err() {
+                                    break 'outer Ok(());
                                 }
-
                                 break;
                             }
                             Err(error) => {
@@ -174,11 +161,38 @@ impl Peer {
             result
         };
 
+        let response_channels = connection_state.response_channels.clone();
         self.connections
             .write()
             .insert(connection_id, connection_state);
 
-        (connection_id, handle_io, incoming_rx)
+        let incoming_rx = incoming_rx.filter_map(move |incoming| {
+            let response_channels = response_channels.clone();
+            async move {
+                if let Some(responding_to) = incoming.responding_to {
+                    let channel = response_channels
+                        .lock()
+                        .as_mut()
+                        .unwrap()
+                        .remove(&responding_to);
+                    if let Some(mut tx) = channel {
+                        tx.send(incoming).await.ok();
+                    } else {
+                        log::warn!("received RPC response to unknown request {}", responding_to);
+                    }
+
+                    None
+                } else {
+                    if let Some(envelope) = proto::build_typed_envelope(connection_id, incoming) {
+                        Some(envelope)
+                    } else {
+                        log::error!("unable to construct a typed envelope");
+                        None
+                    }
+                }
+            }
+        });
+        (connection_id, handle_io, incoming_rx.boxed())
     }
 
     pub fn disconnect(&self, connection_id: ConnectionId) {
@@ -332,7 +346,6 @@ mod tests {
     use super::*;
     use crate::TypedEnvelope;
     use async_tungstenite::tungstenite::Message as WebSocketMessage;
-    use futures::StreamExt as _;
 
     #[test]
     fn test_request_response() {
@@ -421,7 +434,7 @@ mod tests {
             client2.disconnect(client1_conn_id);
 
             async fn handle_messages(
-                mut messages: mpsc::Receiver<Box<dyn AnyTypedEnvelope>>,
+                mut messages: BoxStream<'static, Box<dyn AnyTypedEnvelope>>,
                 peer: Arc<Peer>,
             ) -> Result<()> {
                 while let Some(envelope) = messages.next().await {

crates/server/src/rpc.rs 🔗

@@ -9,9 +9,9 @@ use anyhow::anyhow;
 use async_std::task;
 use async_tungstenite::{tungstenite::protocol::Role, WebSocketStream};
 use collections::{HashMap, HashSet};
-use futures::{future::BoxFuture, FutureExt};
+use futures::{future::BoxFuture, FutureExt, StreamExt};
 use parking_lot::{RwLock, RwLockReadGuard, RwLockWriteGuard};
-use postage::{mpsc, prelude::Sink as _, prelude::Stream as _};
+use postage::{mpsc, prelude::Sink as _};
 use rpc::{
     proto::{self, AnyTypedEnvelope, EnvelopedMessage},
     Connection, ConnectionId, Peer, TypedEnvelope,
@@ -133,7 +133,7 @@ impl Server {
             let handle_io = handle_io.fuse();
             futures::pin_mut!(handle_io);
             loop {
-                let next_message = incoming_rx.recv().fuse();
+                let next_message = incoming_rx.next().fuse();
                 futures::pin_mut!(next_message);
                 futures::select_biased! {
                     message = next_message => {
@@ -2026,7 +2026,7 @@ mod tests {
         });
     }
 
-    #[gpui::test(iterations = 1, seed = 2)]
+    #[gpui::test]
     async fn test_formatting_buffer(mut cx_a: TestAppContext, mut cx_b: TestAppContext) {
         cx_a.foreground().forbid_parking();
         let mut lang_registry = Arc::new(LanguageRegistry::new());
@@ -2425,7 +2425,7 @@ mod tests {
         server.forbid_connections();
         server.disconnect_client(client_b.current_user_id(&cx_b));
         while !matches!(
-            status_b.recv().await,
+            status_b.next().await,
             Some(client::Status::ReconnectionError { .. })
         ) {}
 
@@ -2769,11 +2769,11 @@ mod tests {
                 .await
                 .unwrap();
 
-            let peer_id = PeerId(connection_id_rx.recv().await.unwrap().0);
+            let peer_id = PeerId(connection_id_rx.next().await.unwrap().0);
             let user_store = cx.add_model(|cx| UserStore::new(client.clone(), http, cx));
             let mut authed_user =
                 user_store.read_with(cx, |user_store, _| user_store.watch_current_user());
-            while authed_user.recv().await.unwrap().is_none() {}
+            while authed_user.next().await.unwrap().is_none() {}
 
             TestClient {
                 client,
@@ -2822,7 +2822,7 @@ mod tests {
             async_std::future::timeout(Duration::from_millis(500), async {
                 while !(predicate)(&*self.server.store.read()) {
                     self.foreground.start_waiting();
-                    self.notifications.recv().await;
+                    self.notifications.next().await;
                     self.foreground.finish_waiting();
                 }
             })