executor,store/tikv: fix data race (#2833)

executor/distsql_test.go

@@ -95,7 +95,6 @@ func (s *testSuite) TestCopClientSend(c *C) {
 	// Split the table.
 	cli := tikv.GetMockTiKVClient(s.store)
 	cli.Cluster.SplitTable(cli.MvccStore, tblID, 100)
-	tikv.ClearRegionCache(s.store)
 
 	// Send coprocessor request when the table split.
 	rss, err := tk.Se.Execute("select sum(id) from copclient")

store/tikv/kv.go

@@ -130,12 +130,6 @@ func GetMockTiKVClient(store kv.Storage) *mocktikv.RPCClient {
 	return s.client.(*mocktikv.RPCClient)
 }
 
-// ClearRegionCache clears the region cache in the store.
-func ClearRegionCache(store kv.Storage) {
-	s := store.(*tikvStore)
-	s.regionCache = NewRegionCache(s.regionCache.pdClient)
-}
-
 func (s *tikvStore) Begin() (kv.Transaction, error) {
 	txn, err := newTiKVTxn(s)
 	if err != nil {