DATA RACE at the memChangeHook

[hawkingrei]

Bug Report

Please answer these questions before submitting your issue. Thanks!

1. Minimal reproduce step (Required)

==================
WARNING: DATA RACE
Read at 0x00c001fc5e48 by goroutine 172060:
  github.com/tikv/client-go/v2/internal/unionstore.(*memdbArena).onMemChange()
      external/com_github_tikv_client_go_v2/internal/unionstore/memdb_arena.go:135 +0x2dc
  github.com/tikv/client-go/v2/internal/unionstore.(*memdbArena).enlarge()
      external/com_github_tikv_client_go_v2/internal/unionstore/memdb_arena.go:131 +0x2cb
  github.com/tikv/client-go/v2/internal/unionstore.(*memdbArena).alloc()
      external/com_github_tikv_client_go_v2/internal/unionstore/memdb_arena.go:106 +0x84
  github.com/tikv/client-go/v2/internal/unionstore.(*nodeAllocator).allocNode()
      external/com_github_tikv_client_go_v2/internal/unionstore/memdb_arena.go:251 +0x53
  github.com/tikv/client-go/v2/internal/unionstore.(*MemDB).allocNode()
      external/com_github_tikv_client_go_v2/internal/unionstore/memdb.go:787 +0xe4
  github.com/tikv/client-go/v2/internal/unionstore.(*MemDB).traverse()
      external/com_github_tikv_client_go_v2/internal/unionstore/memdb.go:408 +0x369
  github.com/tikv/client-go/v2/internal/unionstore.(*MemDB).set()
      external/com_github_tikv_client_go_v2/internal/unionstore/memdb.go:333 +0x1ae
  github.com/tikv/client-go/v2/internal/unionstore.(*MemDB).UpdateFlags()
      external/com_github_tikv_client_go_v2/internal/unionstore/memdb.go:248 +0x1ba6
  github.com/tikv/client-go/v2/txnkv/transaction.(*KVTxn).LockKeys()
      external/com_github_tikv_client_go_v2/txnkv/transaction/txn.go:811 +0x1ac7
  github.com/pingcap/tidb/store/driver/txn.(*tikvTxn).LockKeys()
      store/driver/txn/txn_driver.go:75 +0x105
  github.com/pingcap/tidb/session.(*LazyTxn).LockKeys()
      session/txn.go:442 +0x22e
  github.com/pingcap/tidb/executor.doLockKeys()
      executor/executor.go:1275 +0x30d
  github.com/pingcap/tidb/executor.(*SelectLockExec).Next()
      executor/executor.go:1207 +0x78f
  github.com/pingcap/tidb/executor.Next()
      executor/executor.go:329 +0x5c3
  github.com/pingcap/tidb/executor.(*UnionExec).resultPuller()
      executor/executor.go:1853 +0x8e9
  github.com/pingcap/tidb/executor.(*UnionExec).initialize.func1()
      executor/executor.go:1806 +0x64
Previous write at 0x00c001fc5e48 by goroutine 172058:
  sync/atomic.StoreInt64()
      src/runtime/race_amd64.s:237 +0xb
  sync/atomic.StorePointer()
      GOROOT/src/runtime/atomic_pointer.go:51 +0x44
  github.com/tikv/client-go/v2/txnkv/transaction.(*KVTxn).SetMemoryFootprintChangeHook()
      external/com_github_tikv_client_go_v2/txnkv/transaction/txn.go:959 +0x8b
  github.com/pingcap/tidb/store/driver/txn.(*tikvTxn).SetMemoryFootprintChangeHook()
      <autogenerated>:1 +0x29
  github.com/pingcap/tidb/session.(*LazyTxn).SetMemoryFootprintChangeHook()
      session/txn.go:205 +0xc8
  github.com/pingcap/tidb/session.(*session).SetMemoryFootprintChangeHook()
      session/session.go:3677 +0x85
  github.com/pingcap/tidb/session.(*session).Txn()
      session/session.go:2512 +0x79
  github.com/pingcap/tidb/executor.doLockKeys()
      executor/executor.go:1264 +0x165
  github.com/pingcap/tidb/executor.(*SelectLockExec).Next()
      executor/executor.go:1207 +0x78f
  github.com/pingcap/tidb/executor.Next()
      executor/executor.go:329 +0x5c3
  github.com/pingcap/tidb/executor.(*UnionExec).resultPuller()
      executor/executor.go:1853 +0x8e9
  github.com/pingcap/tidb/executor.(*UnionExec).initialize.func1()
      executor/executor.go:1806 +0x64
Goroutine 172060 (running) created at:
  github.com/pingcap/tidb/executor.(*UnionExec).initialize()
      executor/executor.go:1806 +0x4d7
  github.com/pingcap/tidb/executor.(*UnionExec).Next()
      executor/executor.go:1879 +0xca
  github.com/pingcap/tidb/executor.Next()
      executor/executor.go:329 +0x5c3
  github.com/pingcap/tidb/executor.(*HashAggExec).fetchChildData()
      executor/aggregate.go:814 +0x325
  github.com/pingcap/tidb/executor.(*HashAggExec).prepare4ParallelExec.func3()
      executor/aggregate.go:851 +0x64
Goroutine 172058 (running) created at:
  github.com/pingcap/tidb/executor.(*UnionExec).initialize()
      executor/executor.go:1806 +0x4d7
  github.com/pingcap/tidb/executor.(*UnionExec).Next()
      executor/executor.go:1879 +0xca
  github.com/pingcap/tidb/executor.Next()
      executor/executor.go:329 +0x5c3
  github.com/pingcap/tidb/executor.(*HashAggExec).fetchChildData()
      executor/aggregate.go:814 +0x325
  github.com/pingcap/tidb/executor.(*HashAggExec).prepare4ParallelExec.func3()
      executor/aggregate.go:851 +0x64
================== 

2. What did you expect to see? (Required)

3. What did you see instead (Required)

4. What is your TiDB version? (Required)