executor: fix goroutine leak when builder panic (#52471)

close #51693

Author: wshwsh12

pkg/executor/builder.go

@@ -57,6 +57,7 @@ import (
 	"github.com/pingcap/tidb/pkg/parser/ast"
 	"github.com/pingcap/tidb/pkg/parser/model"
 	"github.com/pingcap/tidb/pkg/parser/mysql"
+	"github.com/pingcap/tidb/pkg/parser/terror"
 	plannercore "github.com/pingcap/tidb/pkg/planner/core"
 	plannerutil "github.com/pingcap/tidb/pkg/planner/util"
 	"github.com/pingcap/tidb/pkg/sessionctx"
@@ -4500,11 +4501,20 @@ func (builder *dataReaderBuilder) buildProjectionForIndexJoin(
 	canReorderHandles bool,
 	memTracker *memory.Tracker,
 	interruptSignal *atomic.Value,
-) (exec.Executor, error) {
-	childExec, err := builder.buildExecutorForIndexJoinInternal(ctx, v.Children()[0], lookUpContents, indexRanges, keyOff2IdxOff, cwc, canReorderHandles, memTracker, interruptSignal)
+) (executor exec.Executor, err error) {
+	var childExec exec.Executor
+	childExec, err = builder.buildExecutorForIndexJoinInternal(ctx, v.Children()[0], lookUpContents, indexRanges, keyOff2IdxOff, cwc, canReorderHandles, memTracker, interruptSignal)
 	if err != nil {
 		return nil, err
 	}
+	defer func() {
+		if r := recover(); r != nil {
+			err = util.GetRecoverError(r)
+		}
+		if err != nil {
+			terror.Log(exec.Close(childExec))
+		}
+	}()
 
 	e := &ProjectionExec{
 		BaseExecutor:     exec.NewBaseExecutor(builder.ctx, v.Schema(), v.ID(), childExec),
@@ -4519,9 +4529,16 @@ func (builder *dataReaderBuilder) buildProjectionForIndexJoin(
 	if int64(v.StatsCount()) < int64(builder.ctx.GetSessionVars().MaxChunkSize) {
 		e.numWorkers = 0
 	}
+	failpoint.Inject("buildProjectionForIndexJoinPanic", func(val failpoint.Value) {
+		if v, ok := val.(bool); ok && v {
+			panic("buildProjectionForIndexJoinPanic")
+		}
+	})
 	err = e.open(ctx)
-
-	return e, err
+	if err != nil {
+		return nil, err
+	}
+	return e, nil
 }
 
 // buildRangesForIndexJoin builds kv ranges for index join when the inner plan is index scan plan.

pkg/executor/executor_failpoint_test.go

@@ -699,3 +699,21 @@ func TestHandleForeignKeyCascadePanic(t *testing.T) {
 	err := tk.ExecToErr("replace into t1 values (1, 2);")
 	require.ErrorContains(t, err, "handleForeignKeyCascadeError")
 }
+
+func TestBuildProjectionForIndexJoinPanic(t *testing.T) {
+	// Test no goroutine leak.
+	store := testkit.CreateMockStore(t)
+	tk := testkit.NewTestKit(t, store)
+	tk.MustExec("use test")
+	tk.MustExec("drop table if exists t1, t2;")
+	tk.MustExec("create table t1(a int, b varchar(8));")
+	tk.MustExec("insert into t1 values(1,'1');")
+	tk.MustExec("create table t2(a int , b varchar(8) GENERATED ALWAYS AS (c) VIRTUAL, c varchar(8), PRIMARY KEY (a));")
+	tk.MustExec("insert into t2(a) values(1);")
+	require.NoError(t, failpoint.Enable("github.com/pingcap/tidb/pkg/executor/buildProjectionForIndexJoinPanic", "return(true)"))
+	defer func() {
+		require.NoError(t, failpoint.Disable("github.com/pingcap/tidb/pkg/executor/buildProjectionForIndexJoinPanic"))
+	}()
+	err := tk.QueryToErr("select /*+ tidb_inlj(t2) */ t2.b, t1.b from t1 join t2 ON t2.a=t1.a;")
+	require.ErrorContains(t, err, "buildProjectionForIndexJoinPanic")
+}