From 5d314b6061ca3a056a6428373d369f0f98727f64 Mon Sep 17 00:00:00 2001
From: Max Inden <mail@max-inden.de>
Date: Fri, 5 Apr 2024 16:15:52 +0200
Subject: [PATCH] Prevent busy loop

---
 neqo-http3/src/send_message.rs | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/neqo-http3/src/send_message.rs b/neqo-http3/src/send_message.rs
index 15965c44f6..6fd721a185 100644
--- a/neqo-http3/src/send_message.rs
+++ b/neqo-http3/src/send_message.rs
@@ -157,6 +157,11 @@ impl SendMessage {
     fn get_stream_info(&self) -> Http3StreamInfo {
         Http3StreamInfo::new(self.stream_id(), Http3StreamType::Http)
     }
+
+    fn stream_avail_send_space(&self, conn: &Connection) -> Res<usize> {
+        conn.stream_avail_send_space(self.stream_id())
+            .map_err(|e| Error::map_stream_send_errors(&e.into()))
+    }
 }
 
 impl Stream for SendMessage {
@@ -174,9 +179,7 @@ impl SendStream for SendMessage {
         if self.stream.has_buffered_data() {
             return Ok(0);
         }
-        let available = conn
-            .stream_avail_send_space(self.stream_id())
-            .map_err(|e| Error::map_stream_send_errors(&e.into()))?;
+        let available = self.stream_avail_send_space(conn)?;
         if available <= 2 {
             return Ok(0);
         }
@@ -253,7 +256,8 @@ impl SendStream for SendMessage {
                     Error::HttpInternal(6),
                 )?;
                 qtrace!([self], "done sending request");
-            } else {
+            } else if self.stream_avail_send_space(conn)? > 2 {
+                // TODO: Deduplicate and document 2
                 // DataWritable is just a signal for an application to try to write more data,
                 // if writing fails it is fine. Therefore we do not need to properly check
                 // whether more credits are available on the transport layer.