lanes comment

1 files changed, 5 insertions, 2 deletions

diff --git a/src/swarm/peer/lanes.rs b/src/swarm/peer/lanes.rs
index 88639ea..f40d797 100644
--- a/src/swarm/peer/lanes.rs
+++ b/src/swarm/peer/lanes.rs
@@ -14,8 +14,11 @@ use crate::swarm::sync::handle_sync;
 use crate::transport::SyncEnvelope;
 
 const LANES: usize = 4;
-/// Sync messages waiting per lane. A full lane drops what arrives: its sender gets no
-/// answer and resends after its reply timeout, by which time the backlog is gone.
+/// Sync messages waiting per lane. A full lane drops what arrives, as a lost message:
+/// one its sender awaits an answer to goes again after its reply timeout, by which time
+/// the backlog is gone; one taken as delivered (along a tree) isn't sent again, and what
+/// it carried comes when we ask for it (a later message names it) or with the slow
+/// round (`swarm::relay`).
 const QUEUED_PER_LANE: usize = 256;
 
 pub(crate) struct SyncLanes {