hello again when heard from

While we wait for a peer's HELLO_REPLY, anything else that comes from it
makes our HELLO go again at once, at most once a second, instead of when
the backoff says.

1 files changed, 13 insertions, 2 deletions

diff --git a/src/swarm/peer/inbound.rs b/src/swarm/peer/inbound.rs
index 28066cb..cfafbd3 100644
--- a/src/swarm/peer/inbound.rs
+++ b/src/swarm/peer/inbound.rs
@@ -68,13 +68,19 @@ pub(crate) async fn handle_message(
     // one does). When we heard from it before tells a restarted peer how long it was
     // away (in our HELLO_REPLY).
     let peer_state = state.get_or_create_peer_state(&peer).await;
+    let mut hello_now = false;
     let (reactivated, previously_seen) =
         heard_from(state, &peer, &peer_state, Instant::now(), |peer_state| {
-            if let Some(run) = run {
-                peer_state.returned(run);
+            match run {
+                Some(run) => peer_state.returned(run),
+                // Up and reaching us, while we wait for its HELLO_REPLY.
+                None => hello_now = peer_state.hello_again_now(Instant::now()),
             }
         })
         .await;
+    if hello_now {
+        state.peers_due.now();
+    }
     let same_epoch = observe_peer_epoch(state, &peer, epoch, epoch_seq, run).await;
 
     match message {
@@ -83,7 +89,12 @@ pub(crate) async fn handle_message(
             // restart. It becomes a member right away; our reply makes us one for it.
             let Some(swarm_id) = state.swarm_id().await else {
                 // We are joining ourselves; the peer retries until we know our swarm.
+                // It is up and reaches us: if we wait for its HELLO_REPLY, our HELLO or
+                // the reply was lost, and ours goes again now.
                 debug!(peer = %peer, "HELLO before we know our swarm; not answering yet");
+                if peer_state.lock().await.hello_again_now(Instant::now()) {
+                    state.peers_due.now();
+                }
                 return Ok(());
             };
             if let Some(theirs) = &hello.swarm_id