*: data race at the SessionVars.PlanID

Signed-off-by: Weizhen Wang <wangweizhen@pingcap.com>

executor/analyze_col.go

@@ -84,7 +84,7 @@ func (e *AnalyzeColumnsExec) toV2() *AnalyzeColumnsExecV2 {
 }
 
 func (e *AnalyzeColumnsExec) open(ranges []*ranger.Range) error {
-	e.memTracker = memory.NewTracker(e.ctx.GetSessionVars().PlanID, -1)
+	e.memTracker = memory.NewTracker(int(e.ctx.GetSessionVars().PlanID.Load()), -1)
 	e.memTracker.AttachTo(e.ctx.GetSessionVars().StmtCtx.MemTracker)
 	e.resultHandler = &tableResultHandler{}
 	firstPartRanges, secondPartRanges := distsql.SplitRangesAcrossInt64Boundary(ranges, true, false, !hasPkHist(e.handleCols))

executor/prepared.go

@@ -125,7 +125,7 @@ func (e *PrepareExec) Next(ctx context.Context, req *chunk.Chunk) error {
 		topsql.AttachAndRegisterSQLInfo(ctx, stmt.NormalizedSQL, stmt.SQLDigest, vars.InRestrictedSQL)
 	}
 
-	e.ctx.GetSessionVars().PlanID = 0
+	e.ctx.GetSessionVars().PlanID.Store(0)
 	e.ctx.GetSessionVars().PlanColumnID.Store(0)
 	e.ctx.GetSessionVars().MapHashCode2UniqueID4ExtendedCol = nil
 	// In MySQL prepare protocol, the server need to tell the client how many column the prepared statement would return when executing it.

planner/core/casetest/plan_test.go

@@ -75,7 +75,7 @@ func TestPreferRangeScan(t *testing.T) {
 		} else if i == 1 {
 			tk.MustExec("set session tidb_opt_prefer_range_scan=1")
 		}
-		tk.Session().GetSessionVars().PlanID = 0
+		tk.Session().GetSessionVars().PlanID.Store(0)
 		tk.MustExec(tt)
 		info := tk.Session().ShowProcess()
 		require.NotNil(t, info)
@@ -126,7 +126,7 @@ func TestNormalizedPlan(t *testing.T) {
 	planNormalizedSuiteData := GetPlanNormalizedSuiteData()
 	planNormalizedSuiteData.LoadTestCases(t, &input, &output)
 	for i, tt := range input {
-		tk.Session().GetSessionVars().PlanID = 0
+		tk.Session().GetSessionVars().PlanID.Store(0)
 		tk.MustExec(tt)
 		info := tk.Session().ShowProcess()
 		require.NotNil(t, info)
@@ -174,7 +174,7 @@ func TestNormalizedPlanForDiffStore(t *testing.T) {
 	planNormalizedSuiteData.LoadTestCases(t, &input, &output)
 	lastDigest := ""
 	for i, tt := range input {
-		tk.Session().GetSessionVars().PlanID = 0
+		tk.Session().GetSessionVars().PlanID.Store(0)
 		tk.MustExec(tt)
 		info := tk.Session().ShowProcess()
 		require.NotNil(t, info)

planner/core/casetest/tiflash_selection_late_materialization_test.go

@@ -61,7 +61,7 @@ func TestTiFlashLateMaterialization(t *testing.T) {
 	planNormalizedSuiteData := GetPlanNormalizedSuiteData()
 	planNormalizedSuiteData.LoadTestCases(t, &input, &output)
 	for i, tt := range input {
-		tk.Session().GetSessionVars().PlanID = 0
+		tk.Session().GetSessionVars().PlanID.Store(0)
 		tk.MustExec(tt)
 		info := tk.Session().ShowProcess()
 		require.NotNil(t, info)

planner/core/find_best_task.go

@@ -218,7 +218,7 @@ func (p *baseLogicalPlan) enumeratePhysicalPlans4Task(physicalPlans []PhysicalPl
 		// The curCntPlan records the number of possible plans for pp
 		curCntPlan = 1
 		timeStampNow := p.GetLogicalTS4TaskMap()
-		savedPlanID := p.ctx.GetSessionVars().PlanID
+		savedPlanID := p.ctx.GetSessionVars().PlanID.Load()
 		for j, child := range p.children {
 			childProp := pp.GetChildReqProps(j)
 			childTask, cnt, err := child.findBestTask(childProp, &PlanCounterDisabled, opt)
@@ -240,7 +240,7 @@ func (p *baseLogicalPlan) enumeratePhysicalPlans4Task(physicalPlans []PhysicalPl
 
 		// If the target plan can be found in this physicalPlan(pp), rebuild childTasks to build the corresponding combination.
 		if planCounter.IsForce() && int64(*planCounter) <= curCntPlan {
-			p.ctx.GetSessionVars().PlanID = savedPlanID
+			p.ctx.GetSessionVars().PlanID.Store(savedPlanID)
 			curCntPlan = int64(*planCounter)
 			err := p.rebuildChildTasks(&childTasks, pp, childCnts, int64(*planCounter), timeStampNow, opt)
 			if err != nil {

planner/core/initialize.go

@@ -503,19 +503,17 @@ func (p PhysicalIndexJoin) Init(ctx sessionctx.Context, stats *property.StatsInf
 
 // Init initializes PhysicalIndexMergeJoin.
 func (p PhysicalIndexMergeJoin) Init(ctx sessionctx.Context) *PhysicalIndexMergeJoin {
-	ctx.GetSessionVars().PlanID++
 	p.tp = plancodec.TypeIndexMergeJoin
-	p.id = ctx.GetSessionVars().PlanID
+	p.id = int(ctx.GetSessionVars().PlanID.Add(1))
 	p.ctx = ctx
 	p.self = &p
 	return &p
 }
 
 // Init initializes PhysicalIndexHashJoin.
 func (p PhysicalIndexHashJoin) Init(ctx sessionctx.Context) *PhysicalIndexHashJoin {
-	ctx.GetSessionVars().PlanID++
 	p.tp = plancodec.TypeIndexHashJoin
-	p.id = ctx.GetSessionVars().PlanID
+	p.id = int(ctx.GetSessionVars().PlanID.Add(1))
 	p.ctx = ctx
 	p.self = &p
 	return &p

planner/core/optimizer.go

@@ -148,7 +148,7 @@ type logicalOptRule interface {
 
 // BuildLogicalPlanForTest builds a logical plan for testing purpose from ast.Node.
 func BuildLogicalPlanForTest(ctx context.Context, sctx sessionctx.Context, node ast.Node, infoSchema infoschema.InfoSchema) (Plan, types.NameSlice, error) {
-	sctx.GetSessionVars().PlanID = 0
+	sctx.GetSessionVars().PlanID.Store(0)
 	sctx.GetSessionVars().PlanColumnID.Store(0)
 	builder, _ := NewPlanBuilder().Init(sctx, infoSchema, &utilhint.BlockHintProcessor{})
 	p, err := builder.Build(ctx, node)

planner/core/plan.go

@@ -725,11 +725,10 @@ func (p *logicalSchemaProducer) BuildKeyInfo(selfSchema *expression.Schema, chil
 }
 
 func newBasePlan(ctx sessionctx.Context, tp string, offset int) basePlan {
-	ctx.GetSessionVars().PlanID++
-	id := ctx.GetSessionVars().PlanID
+	id := ctx.GetSessionVars().PlanID.Add(1)
 	return basePlan{
 		tp:          tp,
-		id:          id,
+		id:          int(id),
 		ctx:         ctx,
 		blockOffset: offset,
 	}

planner/core/plan_test.go

@@ -47,7 +47,7 @@ func TestEncodeDecodePlan(t *testing.T) {
 	tk.MustExec("set tidb_enable_collect_execution_info=1;")
 	tk.MustExec("set tidb_partition_prune_mode='static';")
 
-	tk.Session().GetSessionVars().PlanID = 0
+	tk.Session().GetSessionVars().PlanID.Store(0)
 	getPlanTree := func() (str1, str2 string) {
 		info := tk.Session().ShowProcess()
 		require.NotNil(t, info)
@@ -480,7 +480,7 @@ func BenchmarkDecodePlan(b *testing.B) {
 		buf.WriteString(fmt.Sprintf("select count(1) as num,a from t where a='%v' group by a", i))
 	}
 	query := buf.String()
-	tk.Session().GetSessionVars().PlanID = 0
+	tk.Session().GetSessionVars().PlanID.Store(0)
 	tk.MustExec(query)
 	info := tk.Session().ShowProcess()
 	require.NotNil(b, info)
@@ -507,7 +507,7 @@ func BenchmarkEncodePlan(b *testing.B) {
 	tk.MustExec("set @@tidb_slow_log_threshold=200000")
 
 	query := "select count(*) from th t1 join th t2 join th t3 join th t4 join th t5 join th t6 where t1.i=t2.a and t1.i=t3.i and t3.i=t4.i and t4.i=t5.i and t5.i=t6.i"
-	tk.Session().GetSessionVars().PlanID = 0
+	tk.Session().GetSessionVars().PlanID.Store(0)
 	tk.MustExec(query)
 	info := tk.Session().ShowProcess()
 	require.NotNil(b, info)
@@ -531,7 +531,7 @@ func BenchmarkEncodeFlatPlan(b *testing.B) {
 	tk.MustExec("set @@tidb_slow_log_threshold=200000")
 
 	query := "select count(*) from th t1 join th t2 join th t3 join th t4 join th t5 join th t6 where t1.i=t2.a and t1.i=t3.i and t3.i=t4.i and t4.i=t5.i and t5.i=t6.i"
-	tk.Session().GetSessionVars().PlanID = 0
+	tk.Session().GetSessionVars().PlanID.Store(0)
 	tk.MustExec(query)
 	info := tk.Session().ShowProcess()
 	require.NotNil(b, info)

planner/core/point_get_plan.go

@@ -534,7 +534,7 @@ func TryFastPlan(ctx sessionctx.Context, node ast.Node) (p Plan) {
 		return nil
 	}
 
-	ctx.GetSessionVars().PlanID = 0
+	ctx.GetSessionVars().PlanID.Store(0)
 	ctx.GetSessionVars().PlanColumnID.Store(0)
 	switch x := node.(type) {
 	case *ast.SelectStmt:

planner/funcdep/extract_fd_test.go

@@ -217,7 +217,7 @@ func TestFDSet_ExtractFD(t *testing.T) {
 		require.NoError(t, sessiontxn.GetTxnManager(tk.Session()).OnStmtStart(context.TODO(), nil))
 		stmt, err := par.ParseOneStmt(tt.sql, "", "")
 		require.NoError(t, err, comment)
-		tk.Session().GetSessionVars().PlanID = 0
+		tk.Session().GetSessionVars().PlanID.Store(0)
 		tk.Session().GetSessionVars().PlanColumnID.Store(0)
 		err = plannercore.Preprocess(context.Background(), tk.Session(), stmt, plannercore.WithPreprocessorReturn(&plannercore.PreprocessorReturn{InfoSchema: is}))
 		require.NoError(t, err)
@@ -316,7 +316,7 @@ func TestFDSet_ExtractFDForApply(t *testing.T) {
 		comment := fmt.Sprintf("case:%v sql:%s", i, tt.sql)
 		stmt, err := par.ParseOneStmt(tt.sql, "", "")
 		require.NoError(t, err, comment)
-		tk.Session().GetSessionVars().PlanID = 0
+		tk.Session().GetSessionVars().PlanID.Store(0)
 		tk.Session().GetSessionVars().PlanColumnID.Store(0)
 		err = plannercore.Preprocess(context.Background(), tk.Session(), stmt, plannercore.WithPreprocessorReturn(&plannercore.PreprocessorReturn{InfoSchema: is}))
 		require.NoError(t, err, comment)
@@ -364,7 +364,7 @@ func TestFDSet_MakeOuterJoin(t *testing.T) {
 		comment := fmt.Sprintf("case:%v sql:%s", i, tt.sql)
 		stmt, err := par.ParseOneStmt(tt.sql, "", "")
 		require.NoError(t, err, comment)
-		tk.Session().GetSessionVars().PlanID = 0
+		tk.Session().GetSessionVars().PlanID.Store(0)
 		tk.Session().GetSessionVars().PlanColumnID.Store(0)
 		err = plannercore.Preprocess(context.Background(), tk.Session(), stmt, plannercore.WithPreprocessorReturn(&plannercore.PreprocessorReturn{InfoSchema: is}))
 		require.NoError(t, err, comment)

planner/optimize.go

@@ -492,12 +492,12 @@ func OptimizeExecStmt(ctx context.Context, sctx sessionctx.Context,
 }
 
 func buildLogicalPlan(ctx context.Context, sctx sessionctx.Context, node ast.Node, builder *core.PlanBuilder) (core.Plan, error) {
-	sctx.GetSessionVars().PlanID = 0
+	sctx.GetSessionVars().PlanID.Store(0)
 	sctx.GetSessionVars().PlanColumnID.Store(0)
 	sctx.GetSessionVars().MapHashCode2UniqueID4ExtendedCol = nil
 
 	failpoint.Inject("mockRandomPlanID", func() {
-		sctx.GetSessionVars().PlanID = rand.Intn(1000) // nolint:gosec
+		sctx.GetSessionVars().PlanID.Store(rand.Int31n(1000)) // nolint:gosec
 	})
 
 	// reset fields about rewrite

sessionctx/variable/session.go

@@ -699,7 +699,7 @@ type SessionVars struct {
 	ConnectionID uint64
 
 	// PlanID is the unique id of logical and physical plan.
-	PlanID int
+	PlanID atomic.Int32
 
 	// PlanColumnID is the unique id for column when building plan.
 	PlanColumnID atomic.Int64
@@ -1603,8 +1603,7 @@ func (s *SessionVars) BuildParserConfig() parser.ParserConfig {
 
 // AllocNewPlanID alloc new ID
 func (s *SessionVars) AllocNewPlanID() int {
-	s.PlanID++
-	return s.PlanID
+	return int(s.PlanID.Add(1))
 }
 
 const (