From 62fc8d254e636c3053ae8a21c4ea075558a8273f Mon Sep 17 00:00:00 2001
From: Viktor Liu <17948409+lixmal@users.noreply.github.com>
Date: Thu, 16 Jul 2026 01:18:47 +0900
Subject: [PATCH] [relay] Handle QUIC connections concurrently to prevent
 handshake head-of-line blocking (#6784)

---
 relay/server/listener/quic/listener.go | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/relay/server/listener/quic/listener.go b/relay/server/listener/quic/listener.go
index 68f0e03c0..4c3b07571 100644
--- a/relay/server/listener/quic/listener.go
+++ b/relay/server/listener/quic/listener.go
@@ -51,7 +51,10 @@ func (l *Listener) Listen(acceptFn func(conn relaylistener.Conn)) error {
 
 		log.Infof("QUIC client connected from: %s", session.RemoteAddr())
 		conn := NewConn(session)
-		acceptFn(conn)
+		// Run the accept handler (which performs the pre-auth handshake) in its
+		// own goroutine so a slow or stalled handshake cannot block accepting
+		// further connections.
+		go acceptFn(conn)
 	}
 }