data race found in the kv client on the relase-7.1

[3AceShowHand]

==================
WARNING: DATA RACE
Read at 0x00c004305a50 by goroutine 1766:
  runtime.chansend()
      /usr/local/go/src/runtime/chan.go:160 +0x0
  github.com/pingcap/tiflow/cdc/kv.(*eventFeedSession).scheduleRegionRequest.func1()
      /home/jenkins/agent/workspace/pingcap/tiflow/release-7.1/pull_cdc_integration_kafka_test/tiflow/cdc/kv/client.go:544 +0x7c9
  github.com/pingcap/tiflow/cdc/kv.(*eventFeedSession).scheduleRegionRequest()
      /home/jenkins/agent/workspace/pingcap/tiflow/release-7.1/pull_cdc_integration_kafka_test/tiflow/cdc/kv/client.go:594 +0x6d6
  github.com/pingcap/tiflow/cdc/kv.(*eventFeedSession).divideAndSendEventFeedToRegions()
      /home/jenkins/agent/workspace/pingcap/tiflow/release-7.1/pull_cdc_integration_kafka_test/tiflow/cdc/kv/client.go:894 +0xfaf
  github.com/pingcap/tiflow/cdc/kv.(*eventFeedSession).eventFeed.func5.1()
      /home/jenkins/agent/workspace/pingcap/tiflow/release-7.1/pull_cdc_integration_kafka_test/tiflow/cdc/kv/client.go:488 +0xda
  golang.org/x/sync/errgroup.(*Group).Go.func1()
      /go/pkg/mod/golang.org/x/sync@v0.2.0/errgroup/errgroup.go:75 +0x82

Previous write at 0x00c004305a50 by goroutine 1750:
  runtime.closechan()
      /usr/local/go/src/runtime/chan.go:357 +0x0
  github.com/pingcap/tiflow/pkg/chann.(*Chann[...]).unboundedTerminate()
      /home/jenkins/agent/workspace/pingcap/tiflow/release-7.1/pull_cdc_integration_kafka_test/tiflow/pkg/chann/chann.go:223 +0xe4
  github.com/pingcap/tiflow/pkg/chann.(*Chann[...]).unboundedProcessing()
      /home/jenkins/agent/workspace/pingcap/tiflow/release-7.1/pull_cdc_integration_kafka_test/tiflow/pkg/chann/chann.go:190 +0x54c
  github.com/pingcap/tiflow/pkg/chann.New[...].func1()
      /home/jenkins/agent/workspace/pingcap/tiflow/release-7.1/pull_cdc_integration_kafka_test/tiflow/pkg/chann/chann.go:149 +0x47

Goroutine 1766 (running) created at:
  golang.org/x/sync/errgroup.(*Group).Go()
      /go/pkg/mod/golang.org/x/sync@v0.2.0/errgroup/errgroup.go:72 +0x12e
  github.com/pingcap/tiflow/cdc/kv.(*eventFeedSession).eventFeed.func5()
      /home/jenkins/agent/workspace/pingcap/tiflow/release-7.1/pull_cdc_integration_kafka_test/tiflow/cdc/kv/client.go:487 +0x124
  golang.org/x/sync/errgroup.(*Group).Go.func1()
      /go/pkg/mod/golang.org/x/sync@v0.2.0/errgroup/errgroup.go:75 +0x82

Goroutine 1750 (finished) created at:
  github.com/pingcap/tiflow/pkg/chann.New[...]()
      /home/jenkins/agent/workspace/pingcap/tiflow/release-7.1/pull_cdc_integration_kafka_test/tiflow/pkg/chann/chann.go:149 +0x4ca
  github.com/pingcap/tiflow/pkg/chann.NewAutoDrainChann[...]()
      /home/jenkins/agent/workspace/pingcap/tiflow/release-7.1/pull_cdc_integration_kafka_test/tiflow/pkg/chann/drainable_chann.go:27 +0xae
  github.com/pingcap/tiflow/cdc/kv.(*eventFeedSession).eventFeed()
      /home/jenkins/agent/workspace/pingcap/tiflow/release-7.1/pull_cdc_integration_kafka_test/tiflow/cdc/kv/client.go:449 +0x124
  github.com/pingcap/tiflow/cdc/kv.(*CDCClient).EventFeed()
      /home/jenkins/agent/workspace/pingcap/tiflow/release-7.1/pull_cdc_integration_kafka_test/tiflow/cdc/kv/client.go:311 +0x16b
  github.com/pingcap/tiflow/cdc/puller.(*pullerImpl).Run.func1()
      /home/jenkins/agent/workspace/pingcap/tiflow/release-7.1/pull_cdc_integration_kafka_test/tiflow/cdc/puller/puller.go:142 +0x176
  golang.org/x/sync/errgroup.(*Group).Go.func1()
      /go/pkg/mod/golang.org/x/sync@v0.2.0/errgroup/errgroup.go:75 +0x82
==================
panic: send on closed channel

goroutine 1249 [running]:
github.com/pingcap/tiflow/cdc/kv.(*eventFeedSession).scheduleRegionRequest.func1({0x0, 0x63847af382c0003, 0xc004b48258, 0x0, {0x0, 0x0, 0x0}})
	/home/jenkins/agent/workspace/pingcap/tiflow/release-7.1/pull_cdc_integration_kafka_test/tiflow/cdc/kv/client.go:543 +0x80a
github.com/pingcap/tiflow/cdc/kv.(*eventFeedSession).scheduleRegionRequest(0xc00439b7a0, {0xaa834a8, 0xc002787ae0}, {{0x91, 0x7, 0x37}, {0x0, {0xc002d0fd40, 0x12, 0x18}, ...}, ...})
	/home/jenkins/agent/workspace/pingcap/tiflow/release-7.1/pull_cdc_integration_kafka_test/tiflow/cdc/kv/client.go:594 +0x6d7
github.com/pingcap/tiflow/cdc/kv.(*eventFeedSession).divideAndSendEventFeedToRegions(0xc00439b7a0, {0xaa834a8, 0xc002787ae0}, {0x5e, {0xc002d0fd40, 0x12, 0x18}, {0xc002d0fd58, 0x12, 0x18}})
	/home/jenkins/agent/workspace/pingcap/tiflow/release-7.1/pull_cdc_integration_kafka_test/tiflow/cdc/kv/client.go:894 +0xfb0
github.com/pingcap/tiflow/cdc/kv.(*eventFeedSession).eventFeed.func5.1()
	/home/jenkins/agent/workspace/pingcap/tiflow/release-7.1/pull_cdc_integration_kafka_test/tiflow/cdc/kv/client.go:488 +0xdb
golang.org/x/sync/errgroup.(*Group).Go.func1()
	/go/pkg/mod/golang.org/x/sync@v0.2.0/errgroup/errgroup.go:75 +0x83
created by golang.org/x/sync/errgroup.(*Group).Go
	/go/pkg/mod/golang.org/x/sync@v0.2.0/errgroup/errgroup.go:72 +0x12f

[asddongmen]

It seems that a new group was started here at

tiflow/cdc/kv/client.go

Line 489 in 06fcdc5

g, ctx := errgroup.WithContext(ctx)

, causing the goroutine created on line 505

tiflow/cdc/kv/client.go

Line 505 in 9b30691

g.Go(func() error {

to not be waited for by the wait here at

tiflow/cdc/kv/client.go

Line 538 in 9b30691

return g.Wait()

So a data race issue could happen.