test:add control parallel execsql tests (pingcap#6615)

* add control parallel execsql tests

ddl/column.go

@@ -152,6 +152,10 @@ func onAddColumn(d *ddlCtx, t *meta.Meta, job *model.Job) (ver int64, _ error) {
 		if offset != 0 {
 			job.Args = []interface{}{columnInfo, pos, offset}
 		}
+		if err = checkAddColumnTooManyColumns(len(tblInfo.Columns)); err != nil {
+			job.State = model.JobStateCancelled
+			return ver, errors.Trace(err)
+		}
 	}
 
 	originalState := columnInfo.State
@@ -175,10 +179,6 @@ func onAddColumn(d *ddlCtx, t *meta.Meta, job *model.Job) (ver int64, _ error) {
 		// reorganization -> public
 		// Adjust table column offset.
 		adjustColumnInfoInAddColumn(tblInfo, offset)
-		if err = checkAddColumnTooManyColumns(tblInfo.Columns); err != nil {
-			job.State = model.JobStateCancelled
-			return ver, errors.Trace(err)
-		}
 		columnInfo.State = model.StatePublic
 		ver, err = updateVersionAndTableInfo(t, job, tblInfo, originalState != columnInfo.State)
 		if err != nil {
@@ -416,3 +416,10 @@ func allocateColumnID(tblInfo *model.TableInfo) int64 {
 	tblInfo.MaxColumnID++
 	return tblInfo.MaxColumnID
 }
+
+func checkAddColumnTooManyColumns(oldCols int) error {
+	if oldCols > TableColumnCountLimit {
+		return errTooManyFields
+	}
+	return nil
+}

ddl/ddl_api.go

@@ -86,7 +86,6 @@ func (d *ddl) DropSchema(ctx sessionctx.Context, schema model.CIStr) (err error)
 	if !ok {
 		return errors.Trace(infoschema.ErrDatabaseNotExists)
 	}
-
 	job := &model.Job{
 		SchemaID:   old.ID,
 		Type:       model.ActionDropSchema,
@@ -539,13 +538,6 @@ func checkTooManyColumns(colDefs []*ast.ColumnDef) error {
 	return nil
 }
 
-func checkAddColumnTooManyColumns(oldCols []*model.ColumnInfo) error {
-	if len(oldCols) > TableColumnCountLimit {
-		return errTooManyFields
-	}
-	return nil
-}
-
 // checkPointTypeColumns checks multiple decimal/float/double columns.
 func checkPointTypeColumns(colDefs []*ast.ColumnDef) error {
 	for _, colDef := range colDefs {
@@ -1138,7 +1130,9 @@ func (d *ddl) AddColumn(ctx sessionctx.Context, ti ast.Ident, spec *ast.AlterTab
 	if err != nil {
 		return errors.Trace(infoschema.ErrTableNotExists.GenByArgs(ti.Schema, ti.Name))
 	}
-
+	if err = checkAddColumnTooManyColumns(len(t.Cols()) + 1); err != nil {
+		return errors.Trace(err)
+	}
 	// Check whether added column has existed.
 	col := table.FindCol(t.Cols(), colName)
 	if col != nil {

ddl/ddl_db_change_test.go

@@ -535,9 +535,29 @@ func (s *testStateChangeSuite) TestParallelChangeColumnName(c *C) {
 	s.testControlParallelExecSQL(c, sql1, sql2, f)
 }
 
+func (s *testStateChangeSuite) TestParallelAlterAddIndex(c *C) {
+	sql1 := "ALTER TABLE t add index index_b(b);"
+	sql2 := "CREATE INDEX index_b ON t (c);"
+	f := func(c *C, err1, err2 error) {
+		c.Assert(err1, IsNil)
+		c.Assert(err2.Error(), Equals, "[ddl:1061]index already exist index_b")
+	}
+	s.testControlParallelExecSQL(c, sql1, sql2, f)
+}
+
+func (s *testStateChangeSuite) TestParallelDropColumn(c *C) {
+	sql := "ALTER TABLE t drop COLUMN c ;"
+	f := func(c *C, err1, err2 error) {
+		c.Assert(err1, IsNil)
+		c.Assert(err2.Error(), Equals, "[ddl:1091]column c doesn't exist")
+	}
+	s.testControlParallelExecSQL(c, sql, sql, f)
+}
+
 func (s *testStateChangeSuite) TestParallelCreateAndRename(c *C) {
 	sql1 := "create table t_exists(c int);"
 	sql2 := "alter table t rename to t_exists;"
+	defer s.se.Execute(context.Background(), "drop table t_exists")
 	f := func(c *C, err1, err2 error) {
 		c.Assert(err1, IsNil)
 		c.Assert(err2.Error(), Equals, "[schema:1050]Table 't_exists' already exists")

ddl/ddl_db_test.go

@@ -932,12 +932,13 @@ func (s *testDBSuite) TestAddColumnTooMany(c *C) {
 	s.tk.MustExec("use test")
 	count := ddl.TableColumnCountLimit - 1
 	var cols []string
-	for i := 0; i <= count; i++ {
+	for i := 0; i < count; i++ {
 		cols = append(cols, fmt.Sprintf("a%d int", i))
 	}
 	createSQL := fmt.Sprintf("create table t_column_too_many (%s)", strings.Join(cols, ","))
 	s.tk.MustExec(createSQL)
-	alterSQL := "alter table t_column_too_many add column a_512 int"
+	s.tk.MustExec("alter table t_column_too_many add column a_512 int")
+	alterSQL := "alter table t_column_too_many add column a_513 int"
 	s.testErrorCode(c, alterSQL, tmysql.ErrTooManyFields)
 }