From c7a2c4030582e8b7fe413be745e33619daae36e3 Mon Sep 17 00:00:00 2001 From: Benjamin Saunders Date: Sat, 15 Jun 2024 14:16:29 -0700 Subject: [PATCH] Only send MAX_STREAMS when >1/8 of flow control window is consumed --- quinn-proto/src/connection/mod.rs | 4 ++++ quinn-proto/src/connection/streams/state.rs | 19 +++++++++++++++---- 2 files changed, 19 insertions(+), 4 deletions(-) diff --git a/quinn-proto/src/connection/mod.rs b/quinn-proto/src/connection/mod.rs index a0ed44574..22baafa58 100644 --- a/quinn-proto/src/connection/mod.rs +++ b/quinn-proto/src/connection/mod.rs @@ -1311,6 +1311,10 @@ impl Connection { /// `count`s increase both minimum and worst-case memory consumption. pub fn set_max_concurrent_streams(&mut self, dir: Dir, count: VarInt) { self.streams.set_max_concurrent(dir, count); + // If the limit was reduced, then a flow control update previously deemed insignificant may + // now be significant. + let pending = &mut self.spaces[SpaceId::Data].pending; + self.streams.queue_max_stream_id(pending); } /// Current number of remotely initiated streams that may be concurrently open diff --git a/quinn-proto/src/connection/streams/state.rs b/quinn-proto/src/connection/streams/state.rs index 927b2922f..c95d5b14a 100644 --- a/quinn-proto/src/connection/streams/state.rs +++ b/quinn-proto/src/connection/streams/state.rs @@ -748,9 +748,13 @@ impl StreamsState { pub(crate) fn queue_max_stream_id(&mut self, pending: &mut Retransmits) -> bool { let mut queued = false; for dir in Dir::iter() { - let dirty = self.sent_max_remote[dir as usize] != self.max_remote[dir as usize]; - pending.max_stream_id[dir as usize] |= dirty; - queued |= dirty; + let diff = self.max_remote[dir as usize] - self.sent_max_remote[dir as usize]; + // To reduce traffic, only announce updates if at least 1/8 of the flow control window + // has been consumed. + if diff > self.max_concurrent_remote_count[dir as usize] / 8 { + pending.max_stream_id[dir as usize] = true; + queued = true; + } } queued } @@ -921,7 +925,14 @@ mod tests { #[test] fn trivial_flow_control() { - let mut client = make(Side::Client); + let mut client = StreamsState::new( + Side::Client, + 1u32.into(), + 1u32.into(), + 1024 * 1024, + (1024 * 1024u32).into(), + (1024 * 1024u32).into(), + ); let id = StreamId::new(Side::Server, Dir::Uni, 0); let initial_max = client.local_max_data; const MESSAGE_SIZE: usize = 2048;