From 24a1f37892931cafbba18684b08712e653d7a354 Mon Sep 17 00:00:00 2001
From: Daniel Liu <139250065@qq.com>
Date: Mon, 8 Sep 2025 15:38:18 +0800
Subject: [PATCH] ethstats: avoid creating subscriptions on background
 goroutine #22587 (#1445)

---
 ethstats/ethstats.go | 27 ++++++++++++++-------------
 1 file changed, 14 insertions(+), 13 deletions(-)

diff --git a/ethstats/ethstats.go b/ethstats/ethstats.go
index 5100432a8b..f0f4ccbf66 100644
--- a/ethstats/ethstats.go
+++ b/ethstats/ethstats.go
@@ -102,6 +102,9 @@ type Service struct {
 
 	pongCh chan struct{} // Pong notifications are fed into this channel
 	histCh chan []uint64 // History request block numbers are fed into this channel
+
+	headSub event.Subscription
+	txSub   event.Subscription
 }
 
 // connWrapper is a wrapper to prevent concurrent-write or concurrent-read on the
@@ -175,7 +178,12 @@ func New(node *node.Node, backend backend, engine consensus.Engine, url string)
 
 // Start implements node.Lifecycle, starting up the monitoring and reporting daemon.
 func (s *Service) Start() error {
-	go s.loop()
+	// Subscribe to chain events to execute updates on
+	chainHeadCh := make(chan core.ChainHeadEvent, chainHeadChanSize)
+	s.headSub = s.backend.SubscribeChainHeadEvent(chainHeadCh)
+	txEventCh := make(chan core.NewTxsEvent, txChanSize)
+	s.txSub = s.backend.SubscribeNewTxsEvent(txEventCh)
+	go s.loop(chainHeadCh, txEventCh)
 
 	log.Info("Stats daemon started")
 	return nil
@@ -183,22 +191,15 @@ func (s *Service) Start() error {
 
 // Stop implements node.Lifecycle, terminating the monitoring and reporting daemon.
 func (s *Service) Stop() error {
+	s.headSub.Unsubscribe()
+	s.txSub.Unsubscribe()
 	log.Info("Stats daemon stopped")
 	return nil
 }
 
 // loop keeps trying to connect to the netstats server, reporting chain events
 // until termination.
-func (s *Service) loop() {
-	// Subscribe to chain events to execute updates on
-	chainHeadCh := make(chan core.ChainHeadEvent, chainHeadChanSize)
-	headSub := s.backend.SubscribeChainHeadEvent(chainHeadCh)
-	defer headSub.Unsubscribe()
-
-	txEventCh := make(chan core.NewTxsEvent, txChanSize)
-	txSub := s.backend.SubscribeNewTxsEvent(txEventCh)
-	defer txSub.Unsubscribe()
-
+func (s *Service) loop(chainHeadCh chan core.ChainHeadEvent, txEventCh chan core.NewTxsEvent) {
 	// Forensics events
 	forensicsEventCh := make(chan types.ForensicsEvent)
 	if engine, ok := s.engine.(consensusEngine); ok && engine != nil {
@@ -244,9 +245,9 @@ func (s *Service) loop() {
 				}
 
 			// node stopped
-			case <-txSub.Err():
+			case <-s.txSub.Err():
 				break HandleLoop
-			case <-headSub.Err():
+			case <-s.headSub.Err():
 				break HandleLoop
 			}
 		}