From b85d989d0a86227a5f247249e66a62416179e62a Mon Sep 17 00:00:00 2001
From: crazycs <crazycs520@gmail.com>
Date: Thu, 20 Jun 2019 10:47:05 +0800
Subject: [PATCH] ddl: fix race in table lock config (#10848)

---
 ddl/db_test.go     | 30 +++++++-----------------------
 ddl/serial_test.go | 19 +++++++++++++++++++
 2 files changed, 26 insertions(+), 23 deletions(-)

diff --git a/ddl/db_test.go b/ddl/db_test.go
index 0398a8cb8a538..efb48308e1f2c 100644
--- a/ddl/db_test.go
+++ b/ddl/db_test.go
@@ -92,6 +92,8 @@ func setUpSuite(s *testDBSuite, c *C) {
 	s.schemaName = "test_db"
 	s.autoIDStep = autoid.GetStep()
 	ddl.WaitTimeWhenErrorOccured = 0
+	// Test for table lock.
+	config.GetGlobalConfig().EnableTableLock = true
 
 	s.cluster = mocktikv.NewCluster()
 	mocktikv.BootstrapWithSingleStore(s.cluster)
@@ -2887,18 +2889,6 @@ func (s *testDBSuite2) TestLockTables(c *C) {
 	tk.MustExec("create table t1 (a int)")
 	tk.MustExec("create table t2 (a int)")
 
-	// recover table lock config.
-	originValue := config.GetGlobalConfig().EnableTableLock
-	defer func() {
-		config.GetGlobalConfig().EnableTableLock = originValue
-	}()
-
-	// Test for enable table lock config.
-	config.GetGlobalConfig().EnableTableLock = false
-	tk.MustExec("lock tables t1 write")
-	checkTableLock(c, tk.Se, "test", "t1", model.TableLockNone)
-	config.GetGlobalConfig().EnableTableLock = true
-
 	// Test lock 1 table.
 	tk.MustExec("lock tables t1 write")
 	checkTableLock(c, tk.Se, "test", "t1", model.TableLockWrite)
@@ -3074,7 +3064,10 @@ func (s *testDBSuite2) TestLockTables(c *C) {
 }
 
 // TestConcurrentLockTables test concurrent lock/unlock tables.
-func (s *testDBSuite2) TestConcurrentLockTables(c *C) {
+func (s *testDBSuite4) TestConcurrentLockTables(c *C) {
+	if israce.RaceEnabled {
+		c.Skip("skip race test")
+	}
 	s.tk = testkit.NewTestKit(c, s.store)
 	tk2 := testkit.NewTestKit(c, s.store)
 	tk := s.tk
@@ -3084,15 +3077,6 @@ func (s *testDBSuite2) TestConcurrentLockTables(c *C) {
 	tk.MustExec("create table t1 (a int)")
 	tk2.MustExec("use test")
 
-	// recover table lock config.
-	originValue := config.GetGlobalConfig().EnableTableLock
-	defer func() {
-		config.GetGlobalConfig().EnableTableLock = originValue
-	}()
-
-	// Test for enable table lock config.
-	config.GetGlobalConfig().EnableTableLock = true
-
 	// Test concurrent lock tables read.
 	sql1 := "lock tables t1 read"
 	sql2 := "lock tables t1 read"
@@ -3125,7 +3109,7 @@ func (s *testDBSuite2) TestConcurrentLockTables(c *C) {
 	tk2.MustExec("unlock tables")
 }
 
-func (s *testDBSuite2) testParallelExecSQL(c *C, sql1, sql2 string, se1, se2 session.Session, f checkRet) {
+func (s *testDBSuite4) testParallelExecSQL(c *C, sql1, sql2 string, se1, se2 session.Session, f checkRet) {
 	callback := &ddl.TestDDLCallback{}
 	times := 0
 	callback.OnJobRunBeforeExported = func(job *model.Job) {
diff --git a/ddl/serial_test.go b/ddl/serial_test.go
index d4f0803cc66d5..b572d11d1f7ed 100644
--- a/ddl/serial_test.go
+++ b/ddl/serial_test.go
@@ -25,6 +25,7 @@ import (
 	"github.com/pingcap/failpoint"
 	"github.com/pingcap/parser/model"
 	"github.com/pingcap/parser/mysql"
+	"github.com/pingcap/tidb/config"
 	"github.com/pingcap/tidb/ddl"
 	"github.com/pingcap/tidb/domain"
 	"github.com/pingcap/tidb/infoschema"
@@ -509,3 +510,21 @@ func (s *testSerialSuite) TestCanceledJobTakeTime(c *C) {
 	sub := time.Since(startTime)
 	c.Assert(sub, Less, ddl.WaitTimeWhenErrorOccured)
 }
+
+func (s *testSerialSuite) TestTableLocksEnable(c *C) {
+	tk := testkit.NewTestKit(c, s.store)
+	tk.MustExec("use test")
+	tk.MustExec("drop table if exists t1")
+	defer tk.MustExec("drop table if exists t1")
+	tk.MustExec("create table t1 (a int)")
+	// recover table lock config.
+	originValue := config.GetGlobalConfig().EnableTableLock
+	defer func() {
+		config.GetGlobalConfig().EnableTableLock = originValue
+	}()
+
+	// Test for enable table lock config.
+	config.GetGlobalConfig().EnableTableLock = false
+	tk.MustExec("lock tables t1 write")
+	checkTableLock(c, tk.Se, "test", "t1", model.TableLockNone)
+}