in memory allocator

executor/insert_test.go

@@ -1590,3 +1590,120 @@ func (s *testSuite10) TestBinaryLiteralInsertToSet(c *C) {
 	tk.MustExec("insert into bintest(h) values(0x61)")
 	tk.MustQuery("select * from bintest").Check(testkit.Rows("a"))
 }
+
+var _ = SerialSuites(&testSuite13{&baseTestSuite{}})
+
+type testSuite13 struct {
+	*baseTestSuite
+}
+
+func (s *testSuite13) TestGlobalTempTableAutoInc(c *C) {
+	tk := testkit.NewTestKit(c, s.store)
+	tk.MustExec(`use test`)
+	tk.MustExec("drop table if exists temp_test")
+	tk.MustExec("create global temporary table temp_test(id int primary key auto_increment) on commit delete rows")
+	defer tk.MustExec("drop table if exists temp_test")
+
+	// Data is cleared after transaction auto commits.
+	tk.MustExec("insert into temp_test(id) values(0)")
+	tk.MustQuery("select * from temp_test").Check(testkit.Rows())
+
+	// Data is not cleared inside a transaction.
+	tk.MustExec("begin")
+	tk.MustExec("insert into temp_test(id) values(0)")
+	tk.MustQuery("select * from temp_test").Check(testkit.Rows("1"))
+	tk.MustExec("commit")
+
+	// AutoID allocator is cleared.
+	tk.MustExec("begin")
+	tk.MustExec("insert into temp_test(id) values(0)")
+	tk.MustQuery("select * from temp_test").Check(testkit.Rows("1"))
+	// Test whether auto-inc is incremental
+	tk.MustExec("insert into temp_test(id) values(0)")
+	tk.MustQuery("select id from temp_test order by id").Check(testkit.Rows("1", "2"))
+	tk.MustExec("commit")
+
+	// multi-value insert
+	tk.MustExec("begin")
+	tk.MustExec("insert into temp_test(id) values(0), (0)")
+	tk.MustQuery("select id from temp_test order by id").Check(testkit.Rows("1", "2"))
+	tk.MustExec("insert into temp_test(id) values(0), (0)")
+	tk.MustQuery("select id from temp_test order by id").Check(testkit.Rows("1", "2", "3", "4"))
+	tk.MustExec("commit")
+
+	// rebase
+	tk.MustExec("begin")
+	tk.MustExec("insert into temp_test(id) values(10)")
+	tk.MustExec("insert into temp_test(id) values(0)")
+	tk.MustQuery("select id from temp_test order by id").Check(testkit.Rows("10", "11"))
+	tk.MustExec("insert into temp_test(id) values(20), (30)")
+	tk.MustExec("insert into temp_test(id) values(0), (0)")
+	tk.MustQuery("select id from temp_test order by id").Check(testkit.Rows("10", "11", "20", "30", "31", "32"))
+	tk.MustExec("commit")
+}
+
+func (s *testSuite13) TestGlobalTempTableRowID(c *C) {
+	tk := testkit.NewTestKit(c, s.store)
+	tk.MustExec(`use test`)
+	tk.MustExec("drop table if exists temp_test")
+	tk.MustExec("create global temporary table temp_test(id int) on commit delete rows")
+	defer tk.MustExec("drop table if exists temp_test")
+
+	// Data is cleared after transaction auto commits.
+	tk.MustExec("insert into temp_test(id) values(0)")
+	tk.MustQuery("select _tidb_rowid from temp_test").Check(testkit.Rows())
+
+	// Data is not cleared inside a transaction.
+	tk.MustExec("begin")
+	tk.MustExec("insert into temp_test(id) values(0)")
+	tk.MustQuery("select _tidb_rowid from temp_test").Check(testkit.Rows("1"))
+	tk.MustExec("commit")
+
+	// AutoID allocator is cleared.
+	tk.MustExec("begin")
+	tk.MustExec("insert into temp_test(id) values(0)")
+	tk.MustQuery("select _tidb_rowid from temp_test").Check(testkit.Rows("1"))
+	// Test whether row id is incremental
+	tk.MustExec("insert into temp_test(id) values(0)")
+	tk.MustQuery("select _tidb_rowid from temp_test order by _tidb_rowid").Check(testkit.Rows("1", "2"))
+	tk.MustExec("commit")
+
+	// multi-value insert
+	tk.MustExec("begin")
+	tk.MustExec("insert into temp_test(id) values(0), (0)")
+	tk.MustQuery("select _tidb_rowid from temp_test order by _tidb_rowid").Check(testkit.Rows("1", "2"))
+	tk.MustExec("insert into temp_test(id) values(0), (0)")
+	tk.MustQuery("select _tidb_rowid from temp_test order by _tidb_rowid").Check(testkit.Rows("1", "2", "3", "4"))
+	tk.MustExec("commit")
+}
+
+func (s *testSuite13) TestGlobalTempTableParallel(c *C) {
+	tk := testkit.NewTestKit(c, s.store)
+	tk.MustExec(`use test`)
+	tk.MustExec("drop table if exists temp_test")
+	tk.MustExec("create global temporary table temp_test(id int primary key auto_increment) on commit delete rows")
+	defer tk.MustExec("drop table if exists temp_test")
+
+	threads := 8
+	loops := 1
+	wg := sync.WaitGroup{}
+	wg.Add(threads)
+
+	insertFunc := func() {
+		defer wg.Done()
+		newTk := testkit.NewTestKitWithInit(c, s.store)
+		newTk.MustExec("begin")
+		for i := 0; i < loops; i++ {
+			newTk.MustExec("insert temp_test value(0)")
+			newTk.MustExec("insert temp_test value(0), (0)")
+		}
+		maxID := strconv.Itoa(loops * 3)
+		newTk.MustQuery("select max(id) from temp_test").Check(testkit.Rows(maxID))
+		newTk.MustExec("commit")
+	}
+
+	for i := 0; i < threads; i++ {
+		go insertFunc()
+	}
+	wg.Wait()
+}

sessionctx/variable/session.go

@@ -32,6 +32,7 @@ import (
 	"github.com/pingcap/parser"
 	"github.com/pingcap/parser/ast"
 	"github.com/pingcap/parser/auth"
+	"github.com/pingcap/parser/model"
 	"github.com/pingcap/parser/mysql"
 	"github.com/pingcap/parser/terror"
 	pumpcli "github.com/pingcap/tidb-tools/tidb-binlog/pump_client"
@@ -49,6 +50,7 @@ import (
 	"github.com/pingcap/tidb/util/logutil"
 	"github.com/pingcap/tidb/util/rowcodec"
 	"github.com/pingcap/tidb/util/stringutil"
+	"github.com/pingcap/tidb/util/tableutil"
 	"github.com/pingcap/tidb/util/timeutil"
 	"github.com/twmb/murmur3"
 	atomic2 "go.uber.org/atomic"
@@ -174,7 +176,9 @@ type TransactionContext struct {
 	// TableDeltaMap lock to prevent potential data race
 	tdmLock sync.Mutex
 
-	GlobalTemporaryTables map[int64]struct{}
+	// GlobalTemporaryTables is used to store transaction-specific information for global temporary tables.
+	// It can also be stored in sessionCtx with local temporary tables, but it's easier to clean this data after transaction ends.
+	GlobalTemporaryTables map[int64]tableutil.TempTable
 }
 
 // GetShard returns the shard prefix for the next `count` rowids.
@@ -1445,6 +1449,24 @@ func (s *SessionVars) LazyCheckKeyNotExists() bool {
 	return s.PresumeKeyNotExists || (s.TxnCtx.IsPessimistic && !s.StmtCtx.DupKeyAsWarning)
 }
 
+// GetTemporaryTable returns a TempTable by tableInfo.
+func (s *SessionVars) GetTemporaryTable(tblInfo *model.TableInfo) tableutil.TempTable {
+	if tblInfo.TempTableType == model.TempTableGlobal {
+		if s.TxnCtx.GlobalTemporaryTables == nil {
+			s.TxnCtx.GlobalTemporaryTables = make(map[int64]tableutil.TempTable)
+		}
+		globalTempTables := s.TxnCtx.GlobalTemporaryTables
+		globalTempTable, ok := globalTempTables[tblInfo.ID]
+		if !ok {
+			globalTempTable = tableutil.TempTableFromMeta(tblInfo)
+			globalTempTables[tblInfo.ID] = globalTempTable
+		}
+		return globalTempTable
+	}
+	// TODO: check local temporary tables
+	return nil
+}
+
 // special session variables.
 const (
 	SQLModeVar           = "sql_mode"

table/tables/tables.go

@@ -36,6 +36,7 @@ import (
 	"github.com/pingcap/tidb/sessionctx/binloginfo"
 	"github.com/pingcap/tidb/sessionctx/stmtctx"
 	"github.com/pingcap/tidb/sessionctx/variable"
+	"github.com/pingcap/tidb/statistics"
 	tikvstore "github.com/pingcap/tidb/store/tikv/kv"
 	"github.com/pingcap/tidb/table"
 	"github.com/pingcap/tidb/tablecodec"
@@ -46,6 +47,7 @@ import (
 	"github.com/pingcap/tidb/util/generatedexpr"
 	"github.com/pingcap/tidb/util/logutil"
 	"github.com/pingcap/tidb/util/stringutil"
+	"github.com/pingcap/tidb/util/tableutil"
 	"github.com/pingcap/tipb/go-binlog"
 	"github.com/pingcap/tipb/go-tipb"
 	"go.uber.org/zap"
@@ -322,8 +324,8 @@ func (t *TableCommon) UpdateRecord(ctx context.Context, sctx sessionctx.Context,
 	sh := memBuffer.Staging()
 	defer memBuffer.Cleanup(sh)
 
-	if meta := t.Meta(); meta.TempTableType == model.TempTableGlobal {
-		addTemporaryTableID(sctx, meta.ID)
+	if m := t.Meta(); m.TempTableType == model.TempTableGlobal {
+		addTemporaryTable(sctx, m)
 	}
 
 	var colIDs, binlogColIDs []int64
@@ -588,12 +590,9 @@ func TryGetCommonPkColumns(tbl table.Table) []*table.Column {
 	return pkCols
 }
 
-func addTemporaryTableID(sctx sessionctx.Context, id int64) {
-	txnCtx := sctx.GetSessionVars().TxnCtx
-	if txnCtx.GlobalTemporaryTables == nil {
-		txnCtx.GlobalTemporaryTables = make(map[int64]struct{})
-	}
-	txnCtx.GlobalTemporaryTables[id] = struct{}{}
+func addTemporaryTable(sctx sessionctx.Context, tblInfo *model.TableInfo) {
+	tempTable := sctx.GetSessionVars().GetTemporaryTable(tblInfo)
+	tempTable.SetModified(true)
 }
 
 // AddRecord implements table.Table AddRecord interface.
@@ -608,8 +607,8 @@ func (t *TableCommon) AddRecord(sctx sessionctx.Context, r []types.Datum, opts .
 		fn.ApplyOn(&opt)
 	}
 
-	if meta := t.Meta(); meta.TempTableType == model.TempTableGlobal {
-		addTemporaryTableID(sctx, meta.ID)
+	if m := t.Meta(); m.TempTableType == model.TempTableGlobal {
+		addTemporaryTable(sctx, m)
 	}
 
 	var ctx context.Context
@@ -1010,8 +1009,8 @@ func (t *TableCommon) RemoveRecord(ctx sessionctx.Context, h kv.Handle, r []type
 		return err
 	}
 
-	if meta := t.Meta(); meta.TempTableType == model.TempTableGlobal {
-		addTemporaryTableID(ctx, meta.ID)
+	if m := t.Meta(); m.TempTableType == model.TempTableGlobal {
+		addTemporaryTable(ctx, m)
 	}
 
 	// The table has non-public column and this column is doing the operation of "modify/change column".
@@ -1370,7 +1369,14 @@ func OverflowShardBits(recordID int64, shardRowIDBits uint64, typeBitsLength uin
 
 // Allocators implements table.Table Allocators interface.
 func (t *TableCommon) Allocators(ctx sessionctx.Context) autoid.Allocators {
-	if ctx == nil || ctx.GetSessionVars().IDAllocator == nil {
+	if ctx == nil {
+		return t.allocs
+	} else if ctx.GetSessionVars().IDAllocator == nil {
+		// Use an independent allocator for global temporary tables.
+		if t.meta.TempTableType == model.TempTableGlobal {
+			alloc := ctx.GetSessionVars().GetTemporaryTable(t.meta).GetAutoIDAllocator()
+			return autoid.Allocators{alloc}
+		}
 		return t.allocs
 	}
 
@@ -1498,6 +1504,7 @@ func getDuplicateErrorHandleString(t table.Table, handle kv.Handle, row []types.
 func init() {
 	table.TableFromMeta = TableFromMeta
 	table.MockTableFromMeta = MockTableFromMeta
+	tableutil.TempTableFromMeta = TempTableFromMeta
 }
 
 // sequenceCommon cache the sequence value.
@@ -1763,3 +1770,43 @@ func BuildTableScanFromInfos(tableInfo *model.TableInfo, columnInfos []*model.Co
 	}
 	return tsExec
 }
+
+// TemporaryTable is used to store transaction-specific or session-specific information for global / local temporary tables.
+// For example, stats and autoID should have their own copies of data, instead of being shared by all sessions.
+type TemporaryTable struct {
+	// Whether it's modified in this transaction.
+	modified bool
+	// The stats of this table. So far it's always pseudo stats.
+	stats *statistics.Table
+	// The autoID allocator of this table.
+	autoIDAllocator autoid.Allocator
+}
+
+// TempTableFromMeta builds a TempTable from model.TableInfo.
+func TempTableFromMeta(tblInfo *model.TableInfo) tableutil.TempTable {
+	return &TemporaryTable{
+		modified:        false,
+		stats:           statistics.PseudoTable(tblInfo),
+		autoIDAllocator: autoid.NewAllocatorFromTempTblInfo(tblInfo),
+	}
+}
+
+// GetAutoIDAllocator is implemented from TempTable.GetAutoIDAllocator.
+func (t *TemporaryTable) GetAutoIDAllocator() autoid.Allocator {
+	return t.autoIDAllocator
+}
+
+// SetModified is implemented from TempTable.SetModified.
+func (t *TemporaryTable) SetModified(modified bool) {
+	t.modified = modified
+}
+
+// GetModified is implemented from TempTable.GetModified.
+func (t *TemporaryTable) GetModified() bool {
+	return t.modified
+}
+
+// GetStats is implemented from TempTable.GetStats.
+func (t *TemporaryTable) GetStats() interface{} {
+	return t.stats
+}

util/tableutil/tableutil.go

@@ -0,0 +1,40 @@
+// Copyright 2021 PingCAP, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package tableutil
+
+import (
+	"github.com/pingcap/parser/model"
+	"github.com/pingcap/tidb/meta/autoid"
+)
+
+// TempTable is used to store transaction-specific or session-specific information for global / local temporary tables.
+// For example, stats and autoID should have their own copies of data, instead of being shared by all sessions.
+type TempTable interface {
+	// GetAutoIDAllocator gets the autoID allocator of this table.
+	GetAutoIDAllocator() autoid.Allocator
+
+	// SetModified sets that the table is modified.
+	SetModified(bool)
+
+	// GetModified queries whether the table is modified.
+	GetModified() bool
+
+	// The stats of this table (*statistics.Table).
+	// Define the return type as interface{} here to avoid cycle imports.
+	GetStats() interface{}
+}
+
+// TempTableFromMeta builds a TempTable from *model.TableInfo.
+// Currently, it is assigned to tables.TempTableFromMeta in tidb package's init function.
+var TempTableFromMeta func(tblInfo *model.TableInfo) TempTable