*: Move stale read context to TxnManager

executor/adapter.go

@@ -47,6 +47,7 @@ import (
 	"github.com/pingcap/tidb/sessionctx"
 	"github.com/pingcap/tidb/sessionctx/variable"
 	"github.com/pingcap/tidb/sessiontxn"
+	"github.com/pingcap/tidb/sessiontxn/staleread"
 	"github.com/pingcap/tidb/types"
 	"github.com/pingcap/tidb/util/chunk"
 	"github.com/pingcap/tidb/util/execdetails"
@@ -195,11 +196,6 @@ type TelemetryInfo struct {
 type ExecStmt struct {
 	// GoCtx stores parent go context.Context for a stmt.
 	GoCtx context.Context
-	// SnapshotTS stores the timestamp for stale read.
-	// It is not equivalent to session variables's snapshot ts, it only use to build the executor.
-	SnapshotTS uint64
-	// IsStaleness means whether this statement use stale read.
-	IsStaleness bool
 	// ReplicaReadScope indicates the scope the store selector scope the request visited
 	ReplicaReadScope string
 	// InfoSchema stores a reference to the schema information.
@@ -234,6 +230,14 @@ func (a *ExecStmt) PointGet(ctx context.Context, is infoschema.InfoSchema) (*rec
 		defer span1.Finish()
 		ctx = opentracing.ContextWithSpan(ctx, span1)
 	}
+
+	failpoint.Inject("assertTxnManagerInShortPointGetPlan", func() {
+		sessiontxn.RecordAssert(a.Ctx, "assertTxnManagerInShortPointGetPlan", true)
+		// stale read should not reach here
+		staleread.AssertStmtStaleness(a.Ctx, false)
+		sessiontxn.AssertTxnManagerInfoSchema(a.Ctx, is)
+	})
+
 	ctx = a.setPlanLabelForTopSQL(ctx)
 	a.observeStmtBeginForTopSQL()
 	startTs := uint64(math.MaxUint64)
@@ -257,7 +261,7 @@ func (a *ExecStmt) PointGet(ctx context.Context, is infoschema.InfoSchema) (*rec
 		}
 	}
 	if a.PsStmt.Executor == nil {
-		b := newExecutorBuilder(a.Ctx, is, a.Ti, a.SnapshotTS, a.IsStaleness, a.ReplicaReadScope)
+		b := newExecutorBuilder(a.Ctx, is, a.Ti, a.ReplicaReadScope)
 		newExecutor := b.build(a.Plan)
 		if b.err != nil {
 			return nil, b.err
@@ -266,11 +270,6 @@ func (a *ExecStmt) PointGet(ctx context.Context, is infoschema.InfoSchema) (*rec
 	}
 	pointExecutor := a.PsStmt.Executor.(*PointGetExecutor)
 
-	failpoint.Inject("assertTxnManagerInShortPointGetPlan", func() {
-		sessiontxn.RecordAssert(a.Ctx, "assertTxnManagerInShortPointGetPlan", true)
-		sessiontxn.AssertTxnManagerInfoSchema(a.Ctx, is)
-	})
-
 	if err = pointExecutor.Open(ctx); err != nil {
 		terror.Call(pointExecutor.Close)
 		return nil, err
@@ -303,7 +302,7 @@ func (a *ExecStmt) IsReadOnly(vars *variable.SessionVars) bool {
 // It returns the current information schema version that 'a' is using.
 func (a *ExecStmt) RebuildPlan(ctx context.Context) (int64, error) {
 	ret := &plannercore.PreprocessorReturn{}
-	if err := plannercore.Preprocess(a.Ctx, a.StmtNode, plannercore.InTxnRetry, plannercore.WithPreprocessorReturn(ret)); err != nil {
+	if err := plannercore.Preprocess(a.Ctx, a.StmtNode, plannercore.InTxnRetry, plannercore.InitTxnContextProvider, plannercore.WithPreprocessorReturn(ret)); err != nil {
 		return 0, err
 	}
 
@@ -314,11 +313,10 @@ func (a *ExecStmt) RebuildPlan(ctx context.Context) (int64, error) {
 		}
 		sessiontxn.RecordAssert(a.Ctx, "assertTxnManagerInRebuildPlan", true)
 		sessiontxn.AssertTxnManagerInfoSchema(a.Ctx, ret.InfoSchema)
+		staleread.AssertStmtStaleness(a.Ctx, ret.IsStaleness)
 	})
 
 	a.InfoSchema = sessiontxn.GetTxnManager(a.Ctx).GetTxnInfoSchema()
-	a.SnapshotTS = ret.LastSnapshotTS
-	a.IsStaleness = ret.IsStaleness
 	a.ReplicaReadScope = ret.ReadReplicaScope
 	if a.Ctx.GetSessionVars().GetReplicaRead().IsClosestRead() && a.ReplicaReadScope == kv.GlobalReplicaScope {
 		logutil.BgLogger().Warn(fmt.Sprintf("tidb can't read closest replicas due to it haven't %s label", placement.DCLabelKey))
@@ -369,8 +367,13 @@ func (a *ExecStmt) Exec(ctx context.Context) (_ sqlexec.RecordSet, err error) {
 	}()
 
 	failpoint.Inject("assertStaleTSO", func(val failpoint.Value) {
-		if n, ok := val.(int); ok && a.IsStaleness {
-			startTS := oracle.ExtractPhysical(a.SnapshotTS) / 1000
+		if n, ok := val.(int); ok && staleread.IsStmtStaleness(a.Ctx) {
+			txnManager := sessiontxn.GetTxnManager(a.Ctx)
+			ts, err := txnManager.GetReadTS()
+			if err != nil {
+				panic(err)
+			}
+			startTS := oracle.ExtractPhysical(ts) / 1000
 			if n != int(startTS) {
 				panic(fmt.Sprintf("different tso %d != %d", n, startTS))
 			}
@@ -863,7 +866,7 @@ func (a *ExecStmt) buildExecutor() (Executor, error) {
 		ctx.GetSessionVars().StmtCtx.Priority = kv.PriorityLow
 	}
 
-	b := newExecutorBuilder(ctx, a.InfoSchema, a.Ti, a.SnapshotTS, a.IsStaleness, a.ReplicaReadScope)
+	b := newExecutorBuilder(ctx, a.InfoSchema, a.Ti, a.ReplicaReadScope)
 	e := b.build(a.Plan)
 	if b.err != nil {
 		return nil, errors.Trace(b.err)

executor/benchmark_test.go

@@ -292,7 +292,7 @@ func buildHashAggExecutor(ctx sessionctx.Context, src Executor, schema *expressi
 	plan.SetSchema(schema)
 	plan.Init(ctx, nil, 0)
 	plan.SetChildren(nil)
-	b := newExecutorBuilder(ctx, nil, nil, 0, false, oracle.GlobalTxnScope)
+	b := newExecutorBuilder(ctx, nil, nil, oracle.GlobalTxnScope)
 	exec := b.build(plan)
 	hashAgg := exec.(*HashAggExec)
 	hashAgg.children[0] = src
@@ -344,7 +344,7 @@ func buildStreamAggExecutor(ctx sessionctx.Context, srcExec Executor, schema *ex
 		plan = sg
 	}
 
-	b := newExecutorBuilder(ctx, nil, nil, 0, false, oracle.GlobalTxnScope)
+	b := newExecutorBuilder(ctx, nil, nil, oracle.GlobalTxnScope)
 	return b.build(plan)
 }
 
@@ -577,7 +577,7 @@ func buildWindowExecutor(ctx sessionctx.Context, windowFunc string, funcs int, f
 		plan = win
 	}
 
-	b := newExecutorBuilder(ctx, nil, nil, 0, false, oracle.GlobalTxnScope)
+	b := newExecutorBuilder(ctx, nil, nil, oracle.GlobalTxnScope)
 	exec := b.build(plan)
 	return exec
 }
@@ -1317,7 +1317,7 @@ func prepare4IndexInnerHashJoin(tc *indexJoinTestCase, outerDS *mockDataSource,
 		keyOff2IdxOff[i] = i
 	}
 
-	readerBuilder, err := newExecutorBuilder(tc.ctx, nil, nil, 0, false, oracle.GlobalTxnScope).
+	readerBuilder, err := newExecutorBuilder(tc.ctx, nil, nil, oracle.GlobalTxnScope).
 		newDataReaderBuilder(&mockPhysicalIndexReader{e: innerDS})
 	if err != nil {
 		return nil, err
@@ -1391,7 +1391,7 @@ func prepare4IndexMergeJoin(tc *indexJoinTestCase, outerDS *mockDataSource, inne
 		outerCompareFuncs = append(outerCompareFuncs, expression.GetCmpFunction(nil, outerJoinKeys[i], outerJoinKeys[i]))
 	}
 
-	readerBuilder, err := newExecutorBuilder(tc.ctx, nil, nil, 0, false, oracle.GlobalTxnScope).
+	readerBuilder, err := newExecutorBuilder(tc.ctx, nil, nil, oracle.GlobalTxnScope).
 		newDataReaderBuilder(&mockPhysicalIndexReader{e: innerDS})
 	if err != nil {
 		return nil, err

executor/builder.go

@@ -47,6 +47,8 @@ import (
 	"github.com/pingcap/tidb/sessionctx"
 	"github.com/pingcap/tidb/sessionctx/stmtctx"
 	"github.com/pingcap/tidb/sessionctx/variable"
+	"github.com/pingcap/tidb/sessiontxn"
+	"github.com/pingcap/tidb/sessiontxn/staleread"
 	"github.com/pingcap/tidb/statistics"
 	"github.com/pingcap/tidb/store/helper"
 	"github.com/pingcap/tidb/table"
@@ -117,16 +119,27 @@ type CTEStorages struct {
 	IterInTbl cteutil.Storage
 }
 
-func newExecutorBuilder(ctx sessionctx.Context, is infoschema.InfoSchema, ti *TelemetryInfo, snapshotTS uint64, isStaleness bool, replicaReadScope string) *executorBuilder {
-	return &executorBuilder{
+func newExecutorBuilder(ctx sessionctx.Context, is infoschema.InfoSchema, ti *TelemetryInfo, replicaReadScope string) *executorBuilder {
+	b := &executorBuilder{
 		ctx:              ctx,
 		is:               is,
 		Ti:               ti,
-		snapshotTSCached: isStaleness,
-		snapshotTS:       snapshotTS,
-		isStaleness:      isStaleness,
+		isStaleness:      staleread.IsStmtStaleness(ctx),
 		readReplicaScope: replicaReadScope,
 	}
+
+	txnManager := sessiontxn.GetTxnManager(ctx)
+	if provider, ok := txnManager.GetContextProvider().(*sessiontxn.SimpleTxnContextProvider); ok {
+		provider.GetReadTSFunc = b.getReadTS
+		provider.GetForUpdateTSFunc = func() (uint64, error) {
+			if b.forUpdateTS != 0 {
+				return b.forUpdateTS, nil
+			}
+			return b.getReadTS()
+		}
+	}
+
+	return b
 }
 
 // MockPhysicalPlan is used to return a specified executor in when build.
@@ -143,9 +156,9 @@ type MockExecutorBuilder struct {
 }
 
 // NewMockExecutorBuilderForTest is ONLY used in test.
-func NewMockExecutorBuilderForTest(ctx sessionctx.Context, is infoschema.InfoSchema, ti *TelemetryInfo, snapshotTS uint64, isStaleness bool, replicaReadScope string) *MockExecutorBuilder {
+func NewMockExecutorBuilderForTest(ctx sessionctx.Context, is infoschema.InfoSchema, ti *TelemetryInfo, replicaReadScope string) *MockExecutorBuilder {
 	return &MockExecutorBuilder{
-		executorBuilder: newExecutorBuilder(ctx, is, ti, snapshotTS, isStaleness, replicaReadScope)}
+		executorBuilder: newExecutorBuilder(ctx, is, ti, replicaReadScope)}
 }
 
 // Build builds an executor tree according to `p`.
@@ -733,10 +746,6 @@ func (b *executorBuilder) buildExecute(v *plannercore.Execute) Executor {
 	failpoint.Inject("assertStaleReadValuesSameWithExecuteAndBuilder", func() {
 		// This fail point is used to assert the behavior after refactoring is exactly the same with the previous implement.
 		// Some variables in `plannercore.Execute` is deprecated and only be used for asserting now.
-		if b.snapshotTS != v.SnapshotTS {
-			panic(fmt.Sprintf("%d != %d", b.snapshotTS, v.SnapshotTS))
-		}
-
 		if b.isStaleness != v.IsStaleness {
 			panic(fmt.Sprintf("%v != %v", b.isStaleness, v.IsStaleness))
 		}
@@ -746,21 +755,36 @@ func (b *executorBuilder) buildExecute(v *plannercore.Execute) Executor {
 		}
 
 		if v.SnapshotTS != 0 {
-			is, err := domain.GetDomain(b.ctx).GetSnapshotInfoSchema(b.snapshotTS)
+			is, err := domain.GetDomain(b.ctx).GetSnapshotInfoSchema(v.SnapshotTS)
 			if err != nil {
 				panic(err)
 			}
 
 			if b.is.SchemaMetaVersion() != is.SchemaMetaVersion() {
 				panic(fmt.Sprintf("%d != %d", b.is.SchemaMetaVersion(), is.SchemaMetaVersion()))
 			}
+
+			ts, err := sessiontxn.GetTxnManager(b.ctx).GetReadTS()
+			if err != nil {
+				panic(e)
+			}
+
+			if v.SnapshotTS != ts {
+				panic(fmt.Sprintf("%d != %d", ts, v.SnapshotTS))
+			}
 		}
 	})
 
 	failpoint.Inject("assertExecutePrepareStatementStalenessOption", func(val failpoint.Value) {
 		vs := strings.Split(val.(string), "_")
 		assertTS, assertTxnScope := vs[0], vs[1]
-		if strconv.FormatUint(b.snapshotTS, 10) != assertTS ||
+		staleread.AssertStmtStaleness(b.ctx, true)
+		ts, err := sessiontxn.GetTxnManager(b.ctx).GetReadTS()
+		if err != nil {
+			panic(e)
+		}
+
+		if strconv.FormatUint(ts, 10) != assertTS ||
 			assertTxnScope != b.readReplicaScope {
 			panic("execute prepare statement have wrong staleness option")
 		}
@@ -1541,11 +1565,11 @@ func (b *executorBuilder) getSnapshotTS() (uint64, error) {
 		return b.dataReaderTS, nil
 	}
 
-	if (b.inInsertStmt || b.inUpdateStmt || b.inDeleteStmt || b.inSelectLockStmt) && b.forUpdateTS != 0 {
-		return b.forUpdateTS, nil
+	txnManager := sessiontxn.GetTxnManager(b.ctx)
+	if b.inInsertStmt || b.inUpdateStmt || b.inDeleteStmt || b.inSelectLockStmt {
+		return txnManager.GetForUpdateTS()
 	}
-
-	return b.getReadTS()
+	return txnManager.GetReadTS()
 }
 
 // getReadTS returns the ts used by select (without for-update clause). The return value is affected by the isolation level
@@ -1557,6 +1581,11 @@ func (b *executorBuilder) getReadTS() (uint64, error) {
 	// logics. However for `IndexLookUpMergeJoin` and `IndexLookUpHashJoin`, it requires caching the
 	// snapshotTS and and may even use it after the txn being destroyed. In this case, mark
 	// `snapshotTSCached` to skip `refreshForUpdateTSForRC`.
+	failpoint.Inject("assertNotStaleReadForExecutorGetReadTS", func() {
+		// after refactoring stale read will use its own context provider
+		staleread.AssertStmtStaleness(b.ctx, false)
+	})
+
 	if b.snapshotTSCached {
 		return b.snapshotTS, nil
 	}

executor/compiler.go

@@ -16,7 +16,6 @@ package executor
 
 import (
 	"context"
-	"fmt"
 
 	"github.com/opentracing/opentracing-go"
 	"github.com/pingcap/failpoint"
@@ -28,6 +27,7 @@ import (
 	plannercore "github.com/pingcap/tidb/planner/core"
 	"github.com/pingcap/tidb/sessionctx"
 	"github.com/pingcap/tidb/sessiontxn"
+	"github.com/pingcap/tidb/sessiontxn/staleread"
 )
 
 var (
@@ -71,6 +71,10 @@ func (c *Compiler) Compile(ctx context.Context, stmtNode ast.StmtNode) (*ExecStm
 	failpoint.Inject("assertTxnManagerInCompile", func() {
 		sessiontxn.RecordAssert(c.Ctx, "assertTxnManagerInCompile", true)
 		sessiontxn.AssertTxnManagerInfoSchema(c.Ctx, ret.InfoSchema)
+		if ret.LastSnapshotTS != 0 {
+			staleread.AssertStmtStaleness(c.Ctx, true)
+			sessiontxn.AssertTxnManagerReadTS(c.Ctx, ret.LastSnapshotTS)
+		}
 	})
 
 	is := sessiontxn.GetTxnManager(c.Ctx).GetTxnInfoSchema()
@@ -80,11 +84,7 @@ func (c *Compiler) Compile(ctx context.Context, stmtNode ast.StmtNode) (*ExecStm
 	}
 
 	failpoint.Inject("assertStmtCtxIsStaleness", func(val failpoint.Value) {
-		expected := val.(bool)
-		got := c.Ctx.GetSessionVars().StmtCtx.IsStaleness
-		if got != expected {
-			panic(fmt.Sprintf("stmtctx isStaleness wrong, expected:%v, got:%v", expected, got))
-		}
+		staleread.AssertStmtStaleness(c.Ctx, val.(bool))
 	})
 
 	CountStmtNode(stmtNode, c.Ctx.GetSessionVars().InRestrictedSQL)
@@ -94,8 +94,6 @@ func (c *Compiler) Compile(ctx context.Context, stmtNode ast.StmtNode) (*ExecStm
 	}
 	return &ExecStmt{
 		GoCtx:            ctx,
-		SnapshotTS:       ret.LastSnapshotTS,
-		IsStaleness:      ret.IsStaleness,
 		ReplicaReadScope: ret.ReadReplicaScope,
 		InfoSchema:       is,
 		Plan:             finalPlan,

executor/coprocessor.go

@@ -170,7 +170,7 @@ func (h *CoprocessorDAGHandler) buildDAGExecutor(req *coprocessor.Request) (Exec
 	}
 	plan = core.InjectExtraProjection(plan)
 	// Build executor.
-	b := newExecutorBuilder(h.sctx, is, nil, 0, false, oracle.GlobalTxnScope)
+	b := newExecutorBuilder(h.sctx, is, nil, oracle.GlobalTxnScope)
 	return b.build(plan), nil
 }
 

executor/executor.go

@@ -67,6 +67,7 @@ import (
 	topsqlstate "github.com/pingcap/tidb/util/topsql/state"
 	tikverr "github.com/tikv/client-go/v2/error"
 	tikvstore "github.com/tikv/client-go/v2/kv"
+	"github.com/tikv/client-go/v2/oracle"
 	tikvutil "github.com/tikv/client-go/v2/util"
 	atomicutil "go.uber.org/atomic"
 	"go.uber.org/zap"
@@ -1263,7 +1264,7 @@ func init() {
 			ctx = opentracing.ContextWithSpan(ctx, span1)
 		}
 
-		e := &executorBuilder{is: is, ctx: sctx}
+		e := newExecutorBuilder(sctx, is, nil, oracle.GlobalTxnScope)
 		exec := e.build(p)
 		if e.err != nil {
 			return nil, e.err

executor/executor_required_rows_test.go

@@ -846,7 +846,7 @@ func buildMergeJoinExec(ctx sessionctx.Context, joinType plannercore.JoinType, i
 		j.CompareFuncs = append(j.CompareFuncs, expression.GetCmpFunction(nil, j.LeftJoinKeys[i], j.RightJoinKeys[i]))
 	}
 
-	b := newExecutorBuilder(ctx, nil, nil, 0, false, oracle.GlobalTxnScope)
+	b := newExecutorBuilder(ctx, nil, nil, oracle.GlobalTxnScope)
 	return b.build(j)
 }
 

executor/executor_test.go

@@ -3467,7 +3467,7 @@ func TestUnreasonablyClose(t *testing.T) {
 		&plannercore.PhysicalShuffle{},
 		&plannercore.PhysicalUnionAll{},
 	}
-	executorBuilder := executor.NewMockExecutorBuilderForTest(tk.Session(), is, nil, math.MaxUint64, false, "global")
+	executorBuilder := executor.NewMockExecutorBuilderForTest(tk.Session(), is, nil, oracle.GlobalTxnScope)
 
 	opsNeedsCoveredMask := uint64(1<<len(opsNeedsCovered) - 1)
 	opsAlreadyCoveredMask := uint64(0)