*: DATA RACE in the temptable.AttachLocalTemporaryTableInfoSchema (#3…

…8237) close #38236
pingcap · Sep 29, 2022 · 52099eb · 52099eb
1 parent 14d085b
commit 52099eb
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Showing 2 changed files with 8 additions and 5 deletions.
diff --git a/infoschema/infoschema.go b/infoschema/infoschema.go
@@ -623,8 +623,9 @@ func (is *SessionTables) schemaTables(schema model.CIStr) *schemaTables {
 // So when a database is dropped, its temporary tables still exist and can be returned by TableByName/TableByID.
 type SessionExtendedInfoSchema struct {
 	InfoSchema
-	LocalTemporaryTables *SessionTables
-	MdlTables            *SessionTables
+	LocalTemporaryTablesOnce sync.Once
+	LocalTemporaryTables     *SessionTables
+	MdlTables                *SessionTables
 }
 
 // TableByName implements InfoSchema.TableByName

diff --git a/table/temptable/infoschema.go b/table/temptable/infoschema.go
@@ -26,7 +26,9 @@ func AttachLocalTemporaryTableInfoSchema(sctx sessionctx.Context, is infoschema.
 		return is
 	}
 	if se, ok := is.(*infoschema.SessionExtendedInfoSchema); ok {
-		se.LocalTemporaryTables = localTemporaryTables
+		se.LocalTemporaryTablesOnce.Do(func() {
+			se.LocalTemporaryTables = localTemporaryTables
+		})
 		return is
 	}
 
@@ -39,9 +41,9 @@ func AttachLocalTemporaryTableInfoSchema(sctx sessionctx.Context, is infoschema.
 // DetachLocalTemporaryTableInfoSchema detach local temporary table information schema from is
 func DetachLocalTemporaryTableInfoSchema(is infoschema.InfoSchema) infoschema.InfoSchema {
 	if attachedInfoSchema, ok := is.(*infoschema.SessionExtendedInfoSchema); ok {
-		newIs := *attachedInfoSchema
+		newIs := attachedInfoSchema
 		newIs.LocalTemporaryTables = nil
-		return &newIs
+		return newIs
 	}
 
 	return is