From 3c42814b5885b0ae10631c6a8a66b858c7923380 Mon Sep 17 00:00:00 2001
From: Konstantin Lebedev <9497591+kmlebedev@users.noreply.github.com>
Date: Thu, 21 Jul 2022 17:15:10 +0500
Subject: [PATCH] avoid deadlock

---
 weed/server/master_server.go | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/weed/server/master_server.go b/weed/server/master_server.go
index 03a3f74d1..6c0b6652b 100644
--- a/weed/server/master_server.go
+++ b/weed/server/master_server.go
@@ -368,8 +368,16 @@ func (ms *MasterServer) OnPeerUpdate(update *master_pb.ClusterNodeUpdate, startF
 			}
 		}
 		ms.onPeerUpdateLock.RLock()
-		if len(ms.onPeerUpdateDoneCns) > 0 {
-			for _, onPeerUpdateDoneCn := range ms.onPeerUpdateDoneCns {
+		isGtZero := len(ms.onPeerUpdateDoneCns) > 0
+		ms.onPeerUpdateLock.RUnlock()
+		if isGtZero {
+			var chanPtrs []*chan string
+			ms.onPeerUpdateLock.RLock()
+			for _, cn := range ms.onPeerUpdateDoneCns {
+				chanPtrs = append(chanPtrs, cn)
+			}
+			ms.onPeerUpdateLock.RUnlock()
+			for _, onPeerUpdateDoneCn := range chanPtrs {
 				*onPeerUpdateDoneCn <- peerName
 			}
 		}