From e366584728a12cc2ffb06012b4409e0a8b3d68a7 Mon Sep 17 00:00:00 2001
From: Jiaqiang Huang <lzzziver@gmail.com>
Date: Fri, 26 Jul 2024 17:17:19 +0800
Subject: [PATCH] ddl: fix a data race on localRowCntListener Written()
 (#54484)

close pingcap/tidb#54373
---
 pkg/ddl/backfilling.go | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/pkg/ddl/backfilling.go b/pkg/ddl/backfilling.go
index 6e11fd7e5eb59..4fbed0422726d 100644
--- a/pkg/ddl/backfilling.go
+++ b/pkg/ddl/backfilling.go
@@ -782,12 +782,17 @@ type localRowCntListener struct {
 	// prevPhysicalRowCnt records the row count from previous physical tables (partitions).
 	prevPhysicalRowCnt int64
 	// curPhysicalRowCnt records the row count of current physical table.
-	curPhysicalRowCnt int64
+	curPhysicalRowCnt struct {
+		cnt int64
+		mu  sync.Mutex
+	}
 }
 
 func (s *localRowCntListener) Written(rowCnt int) {
-	s.curPhysicalRowCnt += int64(rowCnt)
-	s.reorgCtx.setRowCount(s.prevPhysicalRowCnt + s.curPhysicalRowCnt)
+	s.curPhysicalRowCnt.mu.Lock()
+	s.curPhysicalRowCnt.cnt += int64(rowCnt)
+	s.reorgCtx.setRowCount(s.prevPhysicalRowCnt + s.curPhysicalRowCnt.cnt)
+	s.curPhysicalRowCnt.mu.Unlock()
 	s.counter.Add(float64(rowCnt))
 }