From 3fd30c6e280fba41377c8b563352d756e8bc1caf Mon Sep 17 00:00:00 2001
From: Alex Auvolat <alex@adnab.me>
Date: Thu, 1 Sep 2022 09:45:24 +0200
Subject: [PATCH] recv side: use unbounded channel to remove deadlock

---
 src/recv.rs | 18 ++++++++----------
 1 file changed, 8 insertions(+), 10 deletions(-)

diff --git a/src/recv.rs b/src/recv.rs
index 4d1047b..3bea709 100644
--- a/src/recv.rs
+++ b/src/recv.rs
@@ -15,16 +15,16 @@ use crate::stream::*;
 /// Structure to warn when the sender is dropped before end of stream was reached, like when
 /// connection to some remote drops while transmitting data
 struct Sender {
-	inner: Option<mpsc::Sender<Packet>>,
+	inner: Option<mpsc::UnboundedSender<Packet>>,
 }
 
 impl Sender {
-	fn new(inner: mpsc::Sender<Packet>) -> Self {
+	fn new(inner: mpsc::UnboundedSender<Packet>) -> Self {
 		Sender { inner: Some(inner) }
 	}
 
-	async fn send(&self, packet: Packet) {
-		let _ = self.inner.as_ref().unwrap().send(packet).await;
+	fn send(&self, packet: Packet) {
+		let _ = self.inner.as_ref().unwrap().send(packet);
 	}
 
 	fn end(&mut self) {
@@ -35,9 +35,7 @@ impl Sender {
 impl Drop for Sender {
 	fn drop(&mut self) {
 		if let Some(inner) = self.inner.take() {
-			tokio::spawn(async move {
-				let _ = inner.send(Err(255)).await;
-			});
+			let _ = inner.send(Err(255));
 		}
 	}
 }
@@ -102,18 +100,18 @@ pub(crate) trait RecvLoop: Sync + 'static {
 			let mut sender = if let Some(send) = streams.remove(&(id)) {
 				send
 			} else {
-				let (send, recv) = mpsc::channel(4);
+				let (send, recv) = mpsc::unbounded_channel();
 				trace!("recv_loop: id {} is new channel", id);
 				self.recv_handler(
 					id,
-					Box::pin(tokio_stream::wrappers::ReceiverStream::new(recv)),
+					Box::pin(tokio_stream::wrappers::UnboundedReceiverStream::new(recv)),
 				);
 				Sender::new(send)
 			};
 
 			// If we get an error, the receiving end is disconnected.
 			// We still need to reach eos before dropping this sender
-			let _ = sender.send(packet).await;
+			let _ = sender.send(packet);
 
 			if has_cont {
 				assert!(!is_error);