Use an async Mutex to guard access to write stream in RpcClient

This commit is contained in:
Antonio Scandurra 2021-06-15 10:57:27 +02:00
parent 301531ae04
commit 1d9cfe6b64

View file

@ -1,18 +1,17 @@
use anyhow::{anyhow, Result};
use futures::future::Either;
use gpui::executor::Background;
use parking_lot::Mutex;
use postage::{
barrier, mpsc, oneshot,
barrier, mpsc,
prelude::{Sink, Stream},
};
use smol::{
io::{ReadHalf, WriteHalf},
lock::Mutex,
prelude::{AsyncRead, AsyncWrite},
};
use std::{
collections::HashMap,
io,
sync::{
atomic::{self, AtomicI32},
Arc,
@ -22,21 +21,20 @@ use zed_rpc::proto::{
self, MessageStream, RequestMessage, SendMessage, ServerMessage, SubscribeMessage,
};
pub struct RpcClient {
pub struct RpcClient<Conn> {
response_channels: Arc<Mutex<HashMap<i32, (mpsc::Sender<proto::from_server::Variant>, bool)>>>,
outgoing_tx: mpsc::Sender<(proto::FromClient, oneshot::Sender<io::Result<()>>)>,
outgoing: Mutex<MessageStream<WriteHalf<Conn>>>,
next_message_id: AtomicI32,
_drop_tx: barrier::Sender,
}
impl RpcClient {
pub fn new<Conn>(conn: Conn, executor: Arc<Background>) -> Self
where
Conn: AsyncRead + AsyncWrite + Unpin + Send + 'static,
{
impl<Conn> RpcClient<Conn>
where
Conn: AsyncRead + AsyncWrite + Unpin + Send + 'static,
{
pub fn new(conn: Conn, executor: Arc<Background>) -> Self {
let response_channels = Arc::new(Mutex::new(HashMap::new()));
let (conn_rx, conn_tx) = smol::io::split(conn);
let (outgoing_tx, outgoing_rx) = mpsc::channel(32);
let (_drop_tx, drop_rx) = barrier::channel();
executor
@ -47,27 +45,21 @@ impl RpcClient {
))
.detach();
executor
.spawn(Self::handle_outgoing(conn_tx, outgoing_rx))
.detach();
Self {
response_channels,
outgoing_tx,
outgoing: Mutex::new(MessageStream::new(conn_tx)),
_drop_tx,
next_message_id: AtomicI32::new(0),
}
}
async fn handle_incoming<Conn>(
async fn handle_incoming(
conn: ReadHalf<Conn>,
mut drop_rx: barrier::Receiver,
response_channels: Arc<
Mutex<HashMap<i32, (mpsc::Sender<proto::from_server::Variant>, bool)>>,
>,
) where
Conn: AsyncRead + Unpin,
{
) {
let mut stream = MessageStream::new(conn);
loop {
let read_message = stream.read_message::<proto::FromServer>();
@ -78,11 +70,14 @@ impl RpcClient {
Either::Left((Ok(incoming), _)) => {
if let Some(variant) = incoming.variant {
if let Some(request_id) = incoming.request_id {
let channel = response_channels.lock().remove(&request_id);
let channel = response_channels.lock().await.remove(&request_id);
if let Some((mut tx, oneshot)) = channel {
if tx.send(variant).await.is_ok() {
if !oneshot {
response_channels.lock().insert(request_id, (tx, false));
response_channels
.lock()
.await
.insert(request_id, (tx, false));
}
}
} else {
@ -104,36 +99,21 @@ impl RpcClient {
}
}
async fn handle_outgoing<Conn>(
conn: WriteHalf<Conn>,
mut outgoing_rx: mpsc::Receiver<(proto::FromClient, oneshot::Sender<io::Result<()>>)>,
) where
Conn: AsyncWrite + Unpin,
{
let mut stream = MessageStream::new(conn);
while let Some((message, mut result_tx)) = outgoing_rx.recv().await {
let result = stream.write_message(&message).await;
result_tx.send(result).await.unwrap();
}
}
pub async fn request<T: RequestMessage>(&self, req: T) -> Result<T::Response> {
let message_id = self.next_message_id.fetch_add(1, atomic::Ordering::SeqCst);
let (result_tx, mut result_rx) = oneshot::channel();
let (tx, mut rx) = mpsc::channel(1);
self.response_channels.lock().insert(message_id, (tx, true));
self.outgoing_tx
.clone()
.send((
proto::FromClient {
id: message_id,
variant: Some(req.to_variant()),
},
result_tx,
))
self.response_channels
.lock()
.await
.ok();
result_rx.recv().await.unwrap()?;
.insert(message_id, (tx, true));
self.outgoing
.lock()
.await
.write_message(&proto::FromClient {
id: message_id,
variant: Some(req.to_variant()),
})
.await?;
let response = rx
.recv()
.await
@ -144,19 +124,14 @@ impl RpcClient {
pub async fn send<T: SendMessage>(&self, message: T) -> Result<()> {
let message_id = self.next_message_id.fetch_add(1, atomic::Ordering::SeqCst);
let (result_tx, mut result_rx) = oneshot::channel();
self.outgoing_tx
.clone()
.send((
proto::FromClient {
id: message_id,
variant: Some(message.to_variant()),
},
result_tx,
))
self.outgoing
.lock()
.await
.ok();
result_rx.recv().await.unwrap()?;
.write_message(&proto::FromClient {
id: message_id,
variant: Some(message.to_variant()),
})
.await?;
Ok(())
}
@ -165,23 +140,19 @@ impl RpcClient {
subscription: T,
) -> Result<impl Stream<Item = Result<T::Event>>> {
let message_id = self.next_message_id.fetch_add(1, atomic::Ordering::SeqCst);
let (result_tx, mut result_rx) = oneshot::channel();
let (tx, rx) = mpsc::channel(256);
self.response_channels
.lock()
.insert(message_id, (tx, false));
self.outgoing_tx
.clone()
.send((
proto::FromClient {
id: message_id,
variant: Some(subscription.to_variant()),
},
result_tx,
))
.await
.ok();
result_rx.recv().await.unwrap()?;
.insert(message_id, (tx, false));
self.outgoing
.lock()
.await
.write_message(&proto::FromClient {
id: message_id,
variant: Some(subscription.to_variant()),
})
.await?;
Ok(rx.map(|event| {
T::Event::from_variant(event).ok_or_else(|| anyhow!("invalid event {:?}"))
}))