fix: before exiting, make sure the goroutine has exited (#35411)

#35409

Signed-off-by: fengjun2016 <[email protected]>

internal/datanode/channel/channel_manager.go

@@ -463,9 +463,10 @@ func (r *opRunner) releaseWithTimer(releaseFunc releaseFunc, channel string, opI
 		}
 	}
 
-	finishWaiter.Add(1)
+	finishWaiter.Add(2)
 	go startTimer(&finishWaiter)
 	go func() {
+		defer finishWaiter.Done()
 		// TODO: failure should panic this DN, but we're not sure how
 		//   to recover when releaseFunc stuck.
 		// Whenever we see a stuck, it's a bug need to be fixed.

internal/datanode/channel/channel_manager_test.go

@@ -20,6 +20,7 @@ import (
 	"context"
 	"os"
 	"testing"
+	"time"
 
 	"github.com/cockroachdb/errors"
 	"github.com/stretchr/testify/mock"
@@ -181,11 +182,10 @@ func (s *ChannelManagerSuite) TearDownTest() {
 
 func (s *ChannelManagerSuite) TestReleaseStuck() {
 	var (
-		channel  = "by-dev-rootcoord-dml-2"
-		stuckSig = make(chan struct{})
+		channel = "by-dev-rootcoord-dml-2"
 	)
 	s.manager.releaseFunc = func(channel string) {
-		stuckSig <- struct{}{}
+		time.Sleep(1 * time.Second)
 	}
 
 	info := GetWatchInfoByOpID(100, channel, datapb.ChannelWatchState_ToWatch)
@@ -215,8 +215,6 @@ func (s *ChannelManagerSuite) TestReleaseStuck() {
 	s.True(ok)
 	s.Equal(channel, abchannel)
 
-	<-stuckSig
-
 	resp := s.manager.GetProgress(releaseInfo)
 	s.Equal(datapb.ChannelWatchState_ReleaseFailure, resp.GetState())
 }