executor: fix hang when index join newInnerworker panic (#45890)

executor/index_lookup_join.go

@@ -188,9 +188,10 @@ func (e *IndexLookUpJoin) startWorkers(ctx context.Context) {
 	innerCh := make(chan *lookUpJoinTask, concurrency)
 	e.workerWg.Add(1)
 	go e.newOuterWorker(resultCh, innerCh).run(workerCtx, e.workerWg)
-	e.workerWg.Add(concurrency)
 	for i := 0; i < concurrency; i++ {
-		go e.newInnerWorker(innerCh).run(workerCtx, e.workerWg)
+		innerWorker := e.newInnerWorker(innerCh)
+		e.workerWg.Add(1)
+		go innerWorker.run(workerCtx, e.workerWg)
 	}
 }
 
@@ -232,6 +233,11 @@ func (e *IndexLookUpJoin) newInnerWorker(taskCh chan *lookUpJoinTask) *innerWork
 		lookup:        e,
 		memTracker:    memory.NewTracker(memory.LabelForIndexJoinInnerWorker, -1),
 	}
+	failpoint.Inject("inlNewInnerPanic", func(val failpoint.Value) {
+		if val.(bool) {
+			panic("test inlNewInnerPanic")
+		}
+	})
 	iw.memTracker.AttachTo(e.memTracker)
 	if len(copiedRanges) != 0 {
 		// We should not consume this memory usage in `iw.memTracker`. The

executor/index_lookup_join_test.go

@@ -493,3 +493,21 @@ func TestPartitionTableIndexJoinAndIndexReader(t *testing.T) {
 		tk.MustQuery("select /*+ TIDB_INLJ(t1, t2) */ t1.a from t t1, t t2 where t1.a=t2.b and " + cond).Sort().Check(result)
 	}
 }
+
+func TestIssue45716(t *testing.T) {
+	store := testkit.CreateMockStore(t)
+
+	tk := testkit.NewTestKit(t, store)
+	tk.MustExec("use test")
+	tk.MustExec("set tidb_mem_quota_query = 120000;")
+	tk.MustExec("drop table if exists t1, t2;")
+	tk.MustExec("create table t1(a int, index(a));")
+	tk.MustExec("create table t2(a int, index(a));")
+	tk.MustExec("insert into t1 values (1), (2);")
+	tk.MustExec("insert into t2 values (1),(1),(2),(2);")
+
+	failpoint.Enable("github.com/pingcap/tidb/executor/inlNewInnerPanic", `return(true)`)
+	defer failpoint.Disable("github.com/pingcap/tidb/executor/inlNewInnerPanic")
+	err := tk.QueryToErr("select /*+ inl_join(t2) */ * from t1 join t2 on t1.a = t2.a;")
+	tk.MustContainErrMsg(err.Error(), "test inlNewInnerPanic")
+}