topsql: add more test case for topsql

ddl/backfilling.go

@@ -41,6 +41,7 @@ import (
 	"github.com/pingcap/tidb/util/logutil"
 	decoder "github.com/pingcap/tidb/util/rowDecoder"
 	"github.com/pingcap/tidb/util/timeutil"
+	"github.com/pingcap/tidb/util/topsql"
 	"github.com/tikv/client-go/v2/tikv"
 	"go.uber.org/zap"
 )
@@ -311,6 +312,11 @@ func (w *backfillWorker) run(d *ddlCtx, bf backfiller, job *model.Job) {
 			}
 		})
 
+		failpoint.Inject("mockHighLoadForAddIndex", func() {
+			sqlPrefixes := []string{"alter"}
+			topsql.MockHighCPULoad(job.Query, sqlPrefixes, 5)
+		})
+
 		// Dynamic change batch size.
 		w.batchCnt = int(variable.GetDDLReorgBatchSize())
 		result := w.handleBackfillTask(d, task, bf)

executor/table_reader.go

@@ -17,8 +17,10 @@ package executor
 import (
 	"context"
 	"sort"
+	"time"
 
 	"github.com/opentracing/opentracing-go"
+	"github.com/pingcap/failpoint"
 	"github.com/pingcap/tidb/distsql"
 	"github.com/pingcap/tidb/expression"
 	"github.com/pingcap/tidb/kv"
@@ -125,6 +127,10 @@ func (e *TableReaderExecutor) Open(ctx context.Context) error {
 		defer span1.Finish()
 		ctx = opentracing.ContextWithSpan(ctx, span1)
 	}
+	failpoint.Inject("mockSleepInTableReaderNext", func(v failpoint.Value) {
+		ms := v.(int)
+		time.Sleep(time.Millisecond * time.Duration(ms))
+	})
 
 	e.memTracker = memory.NewTracker(e.id, -1)
 	e.memTracker.AttachTo(e.ctx.GetSessionVars().StmtCtx.MemTracker)

planner/optimize.go

@@ -46,6 +46,7 @@ import (
 	"github.com/pingcap/tidb/util/hint"
 	"github.com/pingcap/tidb/util/logutil"
 	utilparser "github.com/pingcap/tidb/util/parser"
+	"github.com/pingcap/tidb/util/topsql"
 	"go.uber.org/zap"
 )
 
@@ -321,6 +322,11 @@ func optimize(ctx context.Context, sctx sessionctx.Context, node ast.Node, is in
 			failpoint.Return(nil, nil, 0, errors.New("gofail wrong optimizerCnt error"))
 		}
 	})
+	failpoint.Inject("mockHighLoadForOptimize", func() {
+		sqlPrefixes := []string{"select"}
+		topsql.MockHighCPULoad(sctx.GetSessionVars().StmtCtx.OriginalSQL, sqlPrefixes, 10)
+	})
+
 	// build logical plan
 	sctx.GetSessionVars().PlanID = 0
 	sctx.GetSessionVars().PlanColumnID = 0