From e451b0534a317825cdafdea035f5a709ab7d177d Mon Sep 17 00:00:00 2001
From: qinglin89 <316032931@qq.com>
Date: Tue, 19 Jul 2022 15:42:25 +0800
Subject: [PATCH 1/2] get prefetcher before use to avoid been modified bwteen
 access and not-nil condition

---
 core/state/state_object.go |  6 ++++--
 core/state/statedb.go      | 10 ++++++----
 2 files changed, 10 insertions(+), 6 deletions(-)

diff --git a/core/state/state_object.go b/core/state/state_object.go
index 780cd6d255..a526d3ab24 100644
--- a/core/state/state_object.go
+++ b/core/state/state_object.go
@@ -455,9 +455,11 @@ func (s *StateObject) updateTrie(db Database) Trie {
 	}
 	wg.Wait()
 
-	if s.db.prefetcher != nil {
-		s.db.prefetcher.used(s.data.Root, usedStorage)
+	prefetcher := s.db.prefetcher
+	if prefetcher != nil {
+		prefetcher.used(s.data.Root, usedStorage)
 	}
+
 	if len(s.pendingStorage) > 0 {
 		s.pendingStorage = make(Storage)
 	}
diff --git a/core/state/statedb.go b/core/state/statedb.go
index 2edeb379e5..48b366b353 100644
--- a/core/state/statedb.go
+++ b/core/state/statedb.go
@@ -857,8 +857,9 @@ func (s *StateDB) Copy() *StateDB {
 	// If there's a prefetcher running, make an inactive copy of it that can
 	// only access data but does not actively preload (since the user will not
 	// know that they need to explicitly terminate an active copy).
-	if s.prefetcher != nil {
-		state.prefetcher = s.prefetcher.copy()
+	prefetcher := s.prefetcher
+	if prefetcher != nil {
+		state.prefetcher = prefetcher.copy()
 	}
 	if s.snaps != nil {
 		// In order for the miner to be able to use and make additions
@@ -970,8 +971,9 @@ func (s *StateDB) Finalise(deleteEmptyObjects bool) {
 			addressesToPrefetch = append(addressesToPrefetch, common.CopyBytes(addr[:])) // Copy needed for closure
 		}
 	}
-	if s.prefetcher != nil && len(addressesToPrefetch) > 0 {
-		s.prefetcher.prefetch(s.originalRoot, addressesToPrefetch, emptyAddr)
+	prefetcher := s.prefetcher
+	if prefetcher != nil && len(addressesToPrefetch) > 0 {
+		prefetcher.prefetch(s.originalRoot, addressesToPrefetch, emptyAddr)
 	}
 	// Invalidate journal because reverting across transactions is not allowed.
 	s.clearJournalAndRefund()

From 4d92fd7aef8531bd74e5fec96dedd7d923f91cbe Mon Sep 17 00:00:00 2001
From: qinglin89 <316032931@qq.com>
Date: Wed, 20 Jul 2022 10:51:37 +0800
Subject: [PATCH 2/2] some missed s.prefetcher value copy

---
 core/state/state_object.go | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/core/state/state_object.go b/core/state/state_object.go
index a526d3ab24..df6c03e769 100644
--- a/core/state/state_object.go
+++ b/core/state/state_object.go
@@ -169,10 +169,11 @@ func (s *StateObject) getTrie(db Database) Trie {
 	if s.trie == nil {
 		// Try fetching from prefetcher first
 		// We don't prefetch empty tries
-		if s.data.Root != emptyRoot && s.db.prefetcher != nil {
+		prefetcher := s.db.prefetcher
+		if s.data.Root != emptyRoot && prefetcher != nil {
 			// When the miner is creating the pending state, there is no
 			// prefetcher
-			s.trie = s.db.prefetcher.trie(s.data.Root)
+			s.trie = prefetcher.trie(s.data.Root)
 		}
 		if s.trie == nil {
 			var err error
@@ -375,8 +376,9 @@ func (s *StateObject) finalise(prefetch bool) {
 		}
 	}
 
-	if s.db.prefetcher != nil && prefetch && len(slotsToPrefetch) > 0 && s.data.Root != emptyRoot && s.data.Root != dummyRoot {
-		s.db.prefetcher.prefetch(s.data.Root, slotsToPrefetch, s.addrHash)
+	prefetcher := s.db.prefetcher
+	if prefetcher != nil && prefetch && len(slotsToPrefetch) > 0 && s.data.Root != emptyRoot && s.data.Root != dummyRoot {
+		prefetcher.prefetch(s.data.Root, slotsToPrefetch, s.addrHash)
 	}
 	if len(s.dirtyStorage) > 0 {
 		s.dirtyStorage = make(Storage)