ddl: fix a data race (#10900)

pingcap · Jun 21, 2019 · 5cd77cd · 5cd77cd
1 parent 697ba85
commit 5cd77cd
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Showing 3 changed files with 14 additions and 6 deletions.
diff --git a/config/config.go b/config/config.go
@@ -583,7 +583,7 @@ func hasRootPrivilege() bool {
 }
 
 // TableLockEnabled uses to check whether enabled the table lock feature.
-func TableLockEnabled() bool {
+var TableLockEnabled = func() bool {
 	return GetGlobalConfig().EnableTableLock
 }
 

diff --git a/ddl/db_test.go b/ddl/db_test.go
@@ -80,6 +80,14 @@ type testDBSuite struct {
 	autoIDStep int64
 }
 
+var tableLockEnabled uint32 = 0
+
+func init() {
+	config.TableLockEnabled = func() bool {
+		return atomic.LoadUint32(&tableLockEnabled) > 0
+	}
+}
+
 func setUpSuite(s *testDBSuite, c *C) {
 	var err error
 
@@ -90,7 +98,7 @@ func setUpSuite(s *testDBSuite, c *C) {
 	s.autoIDStep = autoid.GetStep()
 	ddl.WaitTimeWhenErrorOccured = 0
 	// Test for table lock.
-	config.GetGlobalConfig().EnableTableLock = true
+	atomic.StoreUint32(&tableLockEnabled, 1)
 
 	s.cluster = mocktikv.NewCluster()
 	mocktikv.BootstrapWithSingleStore(s.cluster)

diff --git a/ddl/serial_test.go b/ddl/serial_test.go
@@ -18,14 +18,14 @@ import (
 	"fmt"
 	"strings"
 	"sync"
+	"sync/atomic"
 	"time"
 
 	. "github.com/pingcap/check"
 	"github.com/pingcap/errors"
 	"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"
@@ -419,13 +419,13 @@ func (s *testSerialSuite) TestTableLocksEnable(c *C) {
 	defer tk.MustExec("drop table if exists t1")
 	tk.MustExec("create table t1 (a int)")
 	// recover table lock config.
-	originValue := config.GetGlobalConfig().EnableTableLock
+	originValue := atomic.LoadUint32(&tableLockEnabled)
 	defer func() {
-		config.GetGlobalConfig().EnableTableLock = originValue
+		atomic.StoreUint32(&tableLockEnabled, originValue)
 	}()
 
 	// Test for enable table lock config.
-	config.GetGlobalConfig().EnableTableLock = false
+	atomic.StoreUint32(&tableLockEnabled, 0)
 	tk.MustExec("lock tables t1 write")
 	checkTableLock(c, tk.Se, "test", "t1", model.TableLockNone)
 }