From b13e36adecf3e4c99e1534e4e99298e754e4bd57 Mon Sep 17 00:00:00 2001
From: taratorio <94537774+taratorio@users.noreply.github.com>
Date: Tue, 23 Apr 2024 17:33:36 +0300
Subject: [PATCH] polygon/sync: message listener to preserve peer events
 ordering

---
 polygon/p2p/message_listener.go | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/polygon/p2p/message_listener.go b/polygon/p2p/message_listener.go
index 38180f13920..f69c15005d7 100644
--- a/polygon/p2p/message_listener.go
+++ b/polygon/p2p/message_listener.go
@@ -170,7 +170,18 @@ func (ml *messageListener) notifyPeerEventObservers(peerEvent *sentry.PeerEvent)
 	ml.observersMu.Lock()
 	defer ml.observersMu.Unlock()
 
-	notifyObservers(ml.peerEventObservers, peerEvent)
+	// wait on all observers to finish processing the peer event before notifying them
+	// with subsequent events in order to preserve the ordering of the sentry messages
+	var wg sync.WaitGroup
+	for _, observer := range ml.peerEventObservers {
+		wg.Add(1)
+		go func(observer MessageObserver[*sentry.PeerEvent]) {
+			defer wg.Done()
+			observer(peerEvent)
+		}(observer)
+	}
+
+	wg.Wait()
 	return nil
 }