client-go/tools/cache: add APIs with context parameter

The context is used for cancellation and to support contextual logging.

In most cases, alternative *WithContext APIs get added, except for
NewIntegerResourceVersionMutationCache where code searches indicate that the
API is not used downstream.

An API break around SharedInformer couldn't be avoided because the
alternative (keeping the interface unchanged and adding a second one with
the new method) would have been worse. controller-runtime needs to be updated
because it implements that interface in a test package. Downstream consumers of
controller-runtime will work unless they use those test package.

Converting Kubernetes to use the other new alternatives will follow. In the
meantime, usage of the new alternatives cannot be enforced via logcheck
yet (see https://github.com/kubernetes/kubernetes/issues/126379 for the
process).

Passing context through and checking it for cancellation is tricky for event
handlers. A better approach is to map the context cancellation to the normal
removal of an event handler via a helper goroutine. Thanks to the new
HandleErrorWithLogr and HandleCrashWithLogr, remembering the logger is
sufficient for handling problems at runtime.

Kubernetes-commit: 4638ba971661497b147906b8977ae206c9dd6e44

examples/workqueue/main.go

@@ -17,6 +17,8 @@ limitations under the License.
 package main
 
 import (
+	"context"
+	"errors"
 	"flag"
 	"fmt"
 	"time"
@@ -116,30 +118,30 @@ func (c *Controller) handleErr(err error, key string) {
 }
 
 // Run begins watching and syncing.
-func (c *Controller) Run(workers int, stopCh chan struct{}) {
+func (c *Controller) Run(ctx context.Context, workers int) {
-	defer runtime.HandleCrash()
+	defer runtime.HandleCrashWithContext(ctx)
 
 	// Let the workers stop when we are done
 	defer c.queue.ShutDown()
 	klog.Info("Starting Pod controller")
 
-	go c.informer.Run(stopCh)
+	go c.informer.RunWithContext(ctx)
 
 	// Wait for all involved caches to be synced, before processing items from the queue is started
-	if !cache.WaitForCacheSync(stopCh, c.informer.HasSynced) {
+	if !cache.WaitForNamedCacheSyncWithContext(ctx, c.informer.HasSynced) {
 		runtime.HandleError(fmt.Errorf("Timed out waiting for caches to sync"))
 		return
 	}
 
 	for i := 0; i < workers; i++ {
-		go wait.Until(c.runWorker, time.Second, stopCh)
+		go wait.UntilWithContext(ctx, c.runWorker, time.Second)
 	}
 
-	<-stopCh
+	<-ctx.Done()
 	klog.Info("Stopping Pod controller")
 }
 
-func (c *Controller) runWorker() {
+func (c *Controller) runWorker(ctx context.Context) {
 	for c.processNextItem() {
 	}
 }
@@ -164,6 +166,8 @@ func main() {
 		klog.Fatal(err)
 	}
 
+	ctx := context.Background()
+
 	// create the pod watcher
 	podListWatcher := cache.NewListWatchFromClient(clientset.CoreV1().RESTClient(), "pods", v1.NamespaceDefault, fields.Everything())
 
@@ -211,9 +215,9 @@ func main() {
 	})
 
 	// Now let's start the controller
-	stop := make(chan struct{})
+	cancelCtx, cancel := context.WithCancelCause(ctx)
-	defer close(stop)
+	defer cancel(errors.New("time to stop because main has completed"))
-	go controller.Run(1, stop)
+	go controller.Run(cancelCtx, 1)
 
 	// Wait forever
 	select {}

tools/cache/cache_test.go

@@ -0,0 +1,25 @@
+/*
+Copyright 2024 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package cache
+
+import (
+	"k8s.io/klog/v2"
+)
+
+func init() {
+	klog.InitFlags(nil)
+}

tools/cache/controller.go

@@ -17,6 +17,7 @@ limitations under the License.
 package cache
 
 import (
+	"context"
 	"errors"
 	"sync"
 	"time"
@@ -79,8 +80,14 @@ type Config struct {
 	RetryOnError bool
 
 	// Called whenever the ListAndWatch drops the connection with an error.
+	//
+	// Contextual logging: WatchErrorHandlerWithContext should be used instead of WatchErrorHandler in code which supports contextual logging.
 	WatchErrorHandler WatchErrorHandler
 
+	// Called whenever the ListAndWatch drops the connection with an error
+	// and WatchErrorHandler is not set.
+	WatchErrorHandlerWithContext WatchErrorHandlerWithContext
+
 	// WatchListPageSize is the requested chunk size of initial and relist watch lists.
 	WatchListPageSize int64
 }
@@ -104,12 +111,21 @@ type controller struct {
 // Controller is a low-level controller that is parameterized by a
 // Config and used in sharedIndexInformer.
 type Controller interface {
-	// Run does two things.  One is to construct and run a Reflector
+	// RunWithContext does two things.  One is to construct and run a Reflector
 	// to pump objects/notifications from the Config's ListerWatcher
 	// to the Config's Queue and possibly invoke the occasional Resync
 	// on that Queue.  The other is to repeatedly Pop from the Queue
 	// and process with the Config's ProcessFunc.  Both of these
-	// continue until `stopCh` is closed.
+	// continue until the context is canceled.
+	//
+	// It's an error to call RunWithContext more than once.
+	// RunWithContext blocks; call via go.
+	RunWithContext(ctx context.Context)
+
+	// Run does the same as RunWithContext with a stop channel instead of
+	// a context.
+	//
+	// Contextual logging: RunWithcontext should be used instead of Run in code which supports contextual logging.
 	Run(stopCh <-chan struct{})
 
 	// HasSynced delegates to the Config's Queue
@@ -129,13 +145,16 @@ func New(c *Config) Controller {
 	return ctlr
 }
 
-// Run begins processing items, and will continue until a value is sent down stopCh or it is closed.
+// Run implements [Controller.Run].
-// It's an error to call Run more than once.
-// Run blocks; call via go.
 func (c *controller) Run(stopCh <-chan struct{}) {
-	defer utilruntime.HandleCrash()
+	c.RunWithContext(wait.ContextForChannel(stopCh))
+}
+
+// RunWithContext implements [Controller.RunWithContext].
+func (c *controller) RunWithContext(ctx context.Context) {
+	defer utilruntime.HandleCrashWithContext(ctx)
 	go func() {
-		<-stopCh
+		<-ctx.Done()
 		c.config.Queue.Close()
 	}()
 	r := NewReflectorWithOptions(
@@ -152,7 +171,11 @@ func (c *controller) Run(stopCh <-chan struct{}) {
 	r.ShouldResync = c.config.ShouldResync
 	r.WatchListPageSize = c.config.WatchListPageSize
 	if c.config.WatchErrorHandler != nil {
-		r.watchErrorHandler = c.config.WatchErrorHandler
+		r.watchErrorHandler = func(_ context.Context, r *Reflector, err error) {
+			c.config.WatchErrorHandler(r, err)
+		}
+	} else if c.config.WatchErrorHandlerWithContext != nil {
+		r.watchErrorHandler = c.config.WatchErrorHandlerWithContext
 	}
 
 	c.reflectorMutex.Lock()
@@ -161,9 +184,9 @@ func (c *controller) Run(stopCh <-chan struct{}) {
 
 	var wg wait.Group
 
-	wg.StartWithChannel(stopCh, r.Run)
+	wg.StartWithContext(ctx, r.RunWithContext)
 
-	wait.Until(c.processLoop, time.Second, stopCh)
+	wait.UntilWithContext(ctx, c.processLoop, time.Second)
 	wg.Wait()
 }
 
@@ -185,13 +208,11 @@ func (c *controller) LastSyncResourceVersion() string {
 // TODO: Consider doing the processing in parallel. This will require a little thought
 // to make sure that we don't end up processing the same object multiple times
 // concurrently.
-//
+func (c *controller) processLoop(ctx context.Context) {
-// TODO: Plumb through the stopCh here (and down to the queue) so that this can
-// actually exit when the controller is stopped. Or just give up on this stuff
-// ever being stoppable. Converting this whole package to use Context would
-// also be helpful.
-func (c *controller) processLoop() {
 	for {
+		// TODO: Plumb through the ctx so that this can
+		// actually exit when the controller is stopped. Or just give up on this stuff
+		// ever being stoppable.
 		obj, err := c.config.Queue.Pop(PopProcessFunc(c.config.Process))
 		if err != nil {
 			if err == ErrFIFOClosed {

tools/cache/controller_test.go

@@ -17,6 +17,7 @@ limitations under the License.
 package cache
 
 import (
+	"context"
 	"fmt"
 	"math/rand"
 	"sync"
@@ -32,6 +33,7 @@ import (
 	"k8s.io/apimachinery/pkg/util/wait"
 	"k8s.io/apimachinery/pkg/watch"
 	fcache "k8s.io/client-go/tools/cache/testing"
+	"k8s.io/klog/v2/ktesting"
 
 	fuzz "github.com/google/gofuzz"
 )
@@ -98,10 +100,10 @@ func Example() {
 		},
 	}
 
-	// Create the controller and run it until we close stop.
+	// Create the controller and run it until we cancel.
-	stop := make(chan struct{})
+	ctx, cancel := context.WithCancel(context.Background())
-	defer close(stop)
+	defer cancel()
-	go New(cfg).Run(stop)
+	go New(cfg).RunWithContext(ctx)
 
 	// Let's add a few objects to the source.
 	testIDs := []string{"a-hello", "b-controller", "c-framework"}
@@ -156,10 +158,10 @@ func ExampleNewInformer() {
 		},
 	)
 
-	// Run the controller and run it until we close stop.
+	// Run the controller and run it until we cancel.
-	stop := make(chan struct{})
+	ctx, cancel := context.WithCancel(context.Background())
-	defer close(stop)
+	defer cancel()
-	go controller.Run(stop)
+	go controller.RunWithContext(ctx)
 
 	// Let's add a few objects to the source.
 	testIDs := []string{"a-hello", "b-controller", "c-framework"}
@@ -227,9 +229,10 @@ func TestHammerController(t *testing.T) {
 		t.Errorf("Expected HasSynced() to return false before we started the controller")
 	}
 
-	// Run the controller and run it until we close stop.
+	// Run the controller and run it until we cancel.
-	stop := make(chan struct{})
+	_, ctx := ktesting.NewTestContext(t)
-	go controller.Run(stop)
+	ctx, cancel := context.WithCancel(ctx)
+	go controller.RunWithContext(ctx)
 
 	// Let's wait for the controller to do its initial sync
 	wait.Poll(100*time.Millisecond, wait.ForeverTestTimeout, func() (bool, error) {
@@ -288,7 +291,7 @@ func TestHammerController(t *testing.T) {
 	// Let's wait for the controller to finish processing the things we just added.
 	// TODO: look in the queue to see how many items need to be processed.
 	time.Sleep(100 * time.Millisecond)
-	close(stop)
+	cancel()
 
 	// TODO: Verify that no goroutines were leaked here and that everything shut
 	// down cleanly.
@@ -385,11 +388,13 @@ func TestUpdate(t *testing.T) {
 		},
 	)
 
-	// Run the controller and run it until we close stop.
+	// Run the controller and run it until we cancel.
 	// Once Run() is called, calls to testDoneWG.Done() might start, so
 	// all testDoneWG.Add() calls must happen before this point
-	stop := make(chan struct{})
+	_, ctx := ktesting.NewTestContext(t)
-	go controller.Run(stop)
+	ctx, cancel := context.WithCancel(ctx)
+	defer cancel()
+	go controller.RunWithContext(ctx)
 	<-watchCh
 
 	// run every test a few times, in parallel
@@ -407,7 +412,6 @@ func TestUpdate(t *testing.T) {
 
 	// Let's wait for the controller to process the things we just added.
 	testDoneWG.Wait()
-	close(stop)
 }
 
 func TestPanicPropagated(t *testing.T) {
@@ -427,9 +431,10 @@ func TestPanicPropagated(t *testing.T) {
 		},
 	)
 
-	// Run the controller and run it until we close stop.
+	// Run the controller and run it until we cancel.
-	stop := make(chan struct{})
+	_, ctx := ktesting.NewTestContext(t)
-	defer close(stop)
+	ctx, cancel := context.WithCancel(ctx)
+	defer cancel()
 
 	propagated := make(chan interface{})
 	go func() {
@@ -438,7 +443,7 @@ func TestPanicPropagated(t *testing.T) {
 				propagated <- r
 			}
 		}()
-		controller.Run(stop)
+		controller.RunWithContext(ctx)
 	}()
 	// Let's add a object to the source. It will trigger a panic.
 	source.Add(&v1.Pod{ObjectMeta: metav1.ObjectMeta{Name: "test"}})
@@ -555,8 +560,10 @@ func TestTransformingInformer(t *testing.T) {
 		}
 	}
 
-	stopCh := make(chan struct{})
+	_, ctx := ktesting.NewTestContext(t)
-	go controller.Run(stopCh)
+	ctx, cancel := context.WithCancel(ctx)
+	defer cancel()
+	go controller.RunWithContext(ctx)
 
 	verifyEvent(watch.Added, nil, expectedPod("pod1", "2"))
 	verifyStore([]interface{}{expectedPod("pod1", "2")})
@@ -574,11 +581,17 @@ func TestTransformingInformer(t *testing.T) {
 	source.Delete(makePod("pod1", "2"))
 	verifyEvent(watch.Deleted, expectedPod("pod1", "2"), nil)
 	verifyStore([]interface{}{expectedPod("pod2", "2"), expectedPod("pod3", "1")})
-
-	close(stopCh)
 }
 
 func TestTransformingInformerRace(t *testing.T) {
+	_, ctx := ktesting.NewTestContext(t)
+	// Canceled *only* when the test is done.
+	testCtx, cancel := context.WithCancel(ctx)
+	defer cancel()
+	// Canceled *also* during the test.
+	ctx, cancel = context.WithCancel(ctx)
+	defer cancel()
+
 	// source simulates an apiserver object endpoint.
 	source := newFakeControllerSource(t)
 
@@ -618,7 +631,11 @@ func TestTransformingInformerRace(t *testing.T) {
 	type event struct{}
 	events := make(chan event, numObjs)
 	recordEvent := func(eventType watch.EventType, previous, current interface{}) {
-		events <- event{}
+		select {
+		case events <- event{}:
+		case <-testCtx.Done():
+			// Don't block forever in the write above when test is already done.
+		}
 	}
 	checkEvents := func(count int) {
 		for i := 0; i < count; i++ {
@@ -637,8 +654,7 @@ func TestTransformingInformerRace(t *testing.T) {
 		podTransformer,
 	)
 
-	stopCh := make(chan struct{})
+	go controller.RunWithContext(ctx)
-	go controller.Run(stopCh)
 
 	checkEvents(numObjs)
 
@@ -652,7 +668,7 @@ func TestTransformingInformerRace(t *testing.T) {
 			key := fmt.Sprintf("namespace/pod-%d", index)
 			for {
 				select {
-				case <-stopCh:
+				case <-ctx.Done():
 					return
 				default:
 				}
@@ -674,7 +690,7 @@ func TestTransformingInformerRace(t *testing.T) {
 	// Let resyncs to happen for some time.
 	time.Sleep(time.Second)
 
-	close(stopCh)
+	cancel()
 	wg.Wait()
 	close(errors)
 	for err := range errors {

tools/cache/delta_fifo.go

@@ -55,6 +55,9 @@ type DeltaFIFOOptions struct {
 	// If set, will be called for objects before enqueueing them. Please
 	// see the comment on TransformFunc for details.
 	Transformer TransformFunc
+
+	// If set, log output will go to this logger instead of klog.Background().
+	Logger *klog.Logger
 }
 
 // DeltaFIFO is like FIFO, but differs in two ways.  One is that the
@@ -136,6 +139,10 @@ type DeltaFIFO struct {
 
 	// Called with every object if non-nil.
 	transformer TransformFunc
+
+	// logger is a per-instance logger. This gets chosen when constructing
+	// the instance, with klog.Background() as default.
+	logger klog.Logger
 }
 
 // TransformFunc allows for transforming an object before it will be processed.
@@ -253,6 +260,10 @@ func NewDeltaFIFOWithOptions(opts DeltaFIFOOptions) *DeltaFIFO {
 
 		emitDeltaTypeReplaced: opts.EmitDeltaTypeReplaced,
 		transformer:           opts.Transformer,
+		logger:                klog.Background(),
+	}
+	if opts.Logger != nil {
+		f.logger = *opts.Logger
 	}
 	f.cond.L = &f.lock
 	return f
@@ -487,10 +498,10 @@ func (f *DeltaFIFO) queueActionInternalLocked(actionType, internalActionType Del
 		// when given a non-empty list (as it is here).
 		// If somehow it happens anyway, deal with it but complain.
 		if oldDeltas == nil {
-			klog.Errorf("Impossible dedupDeltas for id=%q: oldDeltas=%#+v, obj=%#+v; ignoring", id, oldDeltas, obj)
+			f.logger.Error(nil, "Impossible dedupDeltas, ignoring", "id", id, "oldDeltas", oldDeltas, "obj", obj)
 			return nil
 		}
-		klog.Errorf("Impossible dedupDeltas for id=%q: oldDeltas=%#+v, obj=%#+v; breaking invariant by storing empty Deltas", id, oldDeltas, obj)
+		f.logger.Error(nil, "Impossible dedupDeltas, breaking invariant by storing empty Deltas", "id", id, "oldDeltas", oldDeltas, "obj", obj)
 		f.items[id] = newDeltas
 		return fmt.Errorf("Impossible dedupDeltas for id=%q: oldDeltas=%#+v, obj=%#+v; broke DeltaFIFO invariant by storing empty Deltas", id, oldDeltas, obj)
 	}
@@ -597,7 +608,7 @@ func (f *DeltaFIFO) Pop(process PopProcessFunc) (interface{}, error) {
 		item, ok := f.items[id]
 		if !ok {
 			// This should never happen
-			klog.Errorf("Inconceivable! %q was in f.queue but not f.items; ignoring.", id)
+			f.logger.Error(nil, "Inconceivable! Item was in f.queue but not f.items; ignoring", "id", id)
 			continue
 		}
 		delete(f.items, id)
@@ -694,10 +705,10 @@ func (f *DeltaFIFO) Replace(list []interface{}, _ string) error {
 			deletedObj, exists, err := f.knownObjects.GetByKey(k)
 			if err != nil {
 				deletedObj = nil
-				klog.Errorf("Unexpected error %v during lookup of key %v, placing DeleteFinalStateUnknown marker without object", err, k)
+				f.logger.Error(err, "Unexpected error during lookup, placing DeleteFinalStateUnknown marker without object", "key", k)
 			} else if !exists {
 				deletedObj = nil
-				klog.Infof("Key %v does not exist in known objects store, placing DeleteFinalStateUnknown marker without object", k)
+				f.logger.Info("Key does not exist in known objects store, placing DeleteFinalStateUnknown marker without object", "key", k)
 			}
 			queuedDeletions++
 			if err := f.queueActionLocked(Deleted, DeletedFinalStateUnknown{k, deletedObj}); err != nil {
@@ -737,10 +748,10 @@ func (f *DeltaFIFO) Resync() error {
 func (f *DeltaFIFO) syncKeyLocked(key string) error {
 	obj, exists, err := f.knownObjects.GetByKey(key)
 	if err != nil {
-		klog.Errorf("Unexpected error %v during lookup of key %v, unable to queue object for sync", err, key)
+		f.logger.Error(err, "Unexpected error during lookup, unable to queue object for sync", "key", key)
 		return nil
 	} else if !exists {
-		klog.Infof("Key %v does not exist in known objects store, unable to queue object for sync", key)
+		f.logger.Info("Key does not exist in known objects store, unable to queue object for sync", "key", key)
 		return nil
 	}
 

tools/cache/listers.go

@@ -62,7 +62,12 @@ func ListAllByNamespace(indexer Indexer, namespace string, selector labels.Selec
 	items, err := indexer.Index(NamespaceIndex, &metav1.ObjectMeta{Namespace: namespace})
 	if err != nil {
 		// Ignore error; do slow search without index.
-		klog.Warningf("can not retrieve list of objects using index : %v", err)
+		//
+		// ListAllByNamespace is called by generated code
+		// (k8s.io/client-go/listers) and probably not worth converting
+		// to contextual logging, which would require changing all of
+		// those APIs.
+		klog.TODO().Info("Warning: can not retrieve list of objects using index", "err", err)
 		for _, m := range indexer.List() {
 			metadata, err := meta.Accessor(m)
 			if err != nil {

tools/cache/main_test.go

@@ -30,14 +30,6 @@ func TestMain(m *testing.M) {
 		goleak.IgnoreAnyFunction("k8s.io/client-go/tools/cache.TestFIFO_addUpdate.func1"),
 		goleak.IgnoreAnyFunction("k8s.io/client-go/tools/cache.TestDeltaFIFO_addReplace.func1"),
 		goleak.IgnoreAnyFunction("k8s.io/client-go/tools/cache.TestDeltaFIFO_addUpdate.func1"),
-
-		// TODO: fix the following tests by adding WithContext APIs and cancellation.
-		goleak.IgnoreAnyFunction("k8s.io/client-go/tools/cache.TestTransformingInformerRace.func3"),
-		// Created by k8s.io/client-go/tools/cache.TestReflectorListAndWatch, cannot filter on that (https://github.com/uber-go/goleak/issues/135):
-		goleak.IgnoreAnyFunction("k8s.io/client-go/tools/cache.(*Reflector).ListAndWatch"),
-		goleak.IgnoreAnyFunction("k8s.io/client-go/tools/cache.(*Reflector).startResync"),
-		// ???
-		goleak.IgnoreAnyFunction("k8s.io/client-go/tools/cache.(*DeltaFIFO).Close"),
 	}
 	goleak.VerifyTestMain(m, options...)
 }

tools/cache/mutation_cache.go

@@ -60,7 +60,7 @@ type ResourceVersionComparator interface {
 // If includeAdds is true, objects in the mutation cache will be returned even if they don't exist
 // in the underlying store. This is only safe if your use of the cache can handle mutation entries
 // remaining in the cache for up to ttl when mutations and deletes occur very closely in time.
-func NewIntegerResourceVersionMutationCache(backingCache Store, indexer Indexer, ttl time.Duration, includeAdds bool) MutationCache {
+func NewIntegerResourceVersionMutationCache(logger klog.Logger, backingCache Store, indexer Indexer, ttl time.Duration, includeAdds bool) MutationCache {
 	return &mutationCache{
 		backingCache:  backingCache,
 		indexer:       indexer,
@@ -68,6 +68,7 @@ func NewIntegerResourceVersionMutationCache(backingCache Store, indexer Indexer,
 		comparator:    etcdObjectVersioner{},
 		ttl:           ttl,
 		includeAdds:   includeAdds,
+		logger:        logger,
 	}
 }
 
@@ -75,6 +76,7 @@ func NewIntegerResourceVersionMutationCache(backingCache Store, indexer Indexer,
 // since you can't distinguish between, "didn't observe create" and "was deleted after create",
 // if the key is missing from the backing cache, we always return it as missing
 type mutationCache struct {
+	logger        klog.Logger
 	lock          sync.Mutex
 	backingCache  Store
 	indexer       Indexer
@@ -157,7 +159,7 @@ func (c *mutationCache) ByIndex(name string, indexKey string) ([]interface{}, er
 			}
 			elements, err := fn(updated)
 			if err != nil {
-				klog.V(4).Infof("Unable to calculate an index entry for mutation cache entry %s: %v", key, err)
+				c.logger.V(4).Info("Unable to calculate an index entry for mutation cache entry", "key", key, "err", err)
 				continue
 			}
 			for _, inIndex := range elements {
@@ -204,7 +206,7 @@ func (c *mutationCache) Mutation(obj interface{}) {
 	key, err := DeletionHandlingMetaNamespaceKeyFunc(obj)
 	if err != nil {
 		// this is a "nice to have", so failures shouldn't do anything weird
-		utilruntime.HandleError(err)
+		utilruntime.HandleErrorWithLogger(c.logger, err, "DeletionHandlingMetaNamespaceKeyFunc")
 		return
 	}
 

tools/cache/mutation_detector.go

@@ -50,6 +50,7 @@ func NewCacheMutationDetector(name string) MutationDetector {
 	if !mutationDetectionEnabled {
 		return dummyMutationDetector{}
 	}
+	//nolint:logcheck // This code shouldn't be used in production.
 	klog.Warningln("Mutation detector is enabled, this will result in memory leakage.")
 	return &defaultCacheMutationDetector{name: name, period: 1 * time.Second, retainDuration: 2 * time.Minute}
 }

tools/cache/processor_listener_test.go

@@ -22,6 +22,7 @@ import (
 	"time"
 
 	"k8s.io/apimachinery/pkg/util/wait"
+	"k8s.io/klog/v2"
 )
 
 const (
@@ -35,7 +36,7 @@ func BenchmarkListener(b *testing.B) {
 	swg.Add(b.N)
 	b.SetParallelism(concurrencyLevel)
 	// Preallocate enough space so that benchmark does not run out of it
-	pl := newProcessListener(&ResourceEventHandlerFuncs{
+	pl := newProcessListener(klog.Background(), &ResourceEventHandlerFuncs{
 		AddFunc: func(obj interface{}) {
 			swg.Done()
 		},

tools/cache/reflector.go

@@ -95,7 +95,7 @@ type Reflector struct {
 	// lastSyncResourceVersionMutex guards read/write access to lastSyncResourceVersion
 	lastSyncResourceVersionMutex sync.RWMutex
 	// Called whenever the ListAndWatch drops the connection with an error.
-	watchErrorHandler WatchErrorHandler
+	watchErrorHandler WatchErrorHandlerWithContext
 	// WatchListPageSize is the requested chunk size of initial and resync watch lists.
 	// If unset, for consistent reads (RV="") or reads that opt-into arbitrarily old data
 	// (RV="0") it will default to pager.PageSize, for the rest (RV != "" && RV != "0")
@@ -150,20 +150,32 @@ type ResourceVersionUpdater interface {
 // should be offloaded.
 type WatchErrorHandler func(r *Reflector, err error)
 
-// DefaultWatchErrorHandler is the default implementation of WatchErrorHandler
+// The WatchErrorHandler is called whenever ListAndWatch drops the
-func DefaultWatchErrorHandler(r *Reflector, err error) {
+// connection with an error. After calling this handler, the informer
+// will backoff and retry.
+//
+// The default implementation looks at the error type and tries to log
+// the error message at an appropriate level.
+//
+// Implementations of this handler may display the error message in other
+// ways. Implementations should return quickly - any expensive processing
+// should be offloaded.
+type WatchErrorHandlerWithContext func(ctx context.Context, r *Reflector, err error)
+
+// DefaultWatchErrorHandler is the default implementation of WatchErrorHandlerWithContext.
+func DefaultWatchErrorHandler(ctx context.Context, r *Reflector, err error) {
 	switch {
 	case isExpiredError(err):
 		// Don't set LastSyncResourceVersionUnavailable - LIST call with ResourceVersion=RV already
 		// has a semantic that it returns data at least as fresh as provided RV.
 		// So first try to LIST with setting RV to resource version of last observed object.
-		klog.V(4).Infof("%s: watch of %v closed with: %v", r.name, r.typeDescription, err)
+		klog.FromContext(ctx).V(4).Info("Watch closed", "reflector", r.name, "type", r.typeDescription, "err", err)
 	case err == io.EOF:
 		// watch closed normally
 	case err == io.ErrUnexpectedEOF:
-		klog.V(1).Infof("%s: Watch for %v closed with unexpected EOF: %v", r.name, r.typeDescription, err)
+		klog.FromContext(ctx).V(1).Info("Watch closed with unexpected EOF", "reflector", r.name, "type", r.typeDescription, "err", err)
 	default:
-		utilruntime.HandleError(fmt.Errorf("%s: Failed to watch %v: %v", r.name, r.typeDescription, err))
+		utilruntime.HandleErrorWithContext(ctx, err, "Failed to watch", "reflector", r.name, "type", r.typeDescription)
 	}
 }
 
@@ -243,7 +255,7 @@ func NewReflectorWithOptions(lw ListerWatcher, expectedType interface{}, store S
 		// 0.22 QPS. If we don't backoff for 2min, assume API server is healthy and we reset the backoff.
 		backoffManager:    wait.NewExponentialBackoffManager(800*time.Millisecond, 30*time.Second, 2*time.Minute, 2.0, 1.0, reflectorClock),
 		clock:             reflectorClock,
-		watchErrorHandler: WatchErrorHandler(DefaultWatchErrorHandler),
+		watchErrorHandler: WatchErrorHandlerWithContext(DefaultWatchErrorHandler),
 		expectedType:      reflect.TypeOf(expectedType),
 	}
 
@@ -309,14 +321,24 @@ var internalPackages = []string{"client-go/tools/cache/"}
 // Run repeatedly uses the reflector's ListAndWatch to fetch all the
 // objects and subsequent deltas.
 // Run will exit when stopCh is closed.
+//
+// Contextual logging: RunWithContext should be used instead of Run in code which supports contextual logging.
 func (r *Reflector) Run(stopCh <-chan struct{}) {
-	klog.V(3).Infof("Starting reflector %s (%s) from %s", r.typeDescription, r.resyncPeriod, r.name)
+	r.RunWithContext(wait.ContextForChannel(stopCh))
+}
+
+// RunWithContext repeatedly uses the reflector's ListAndWatch to fetch all the
+// objects and subsequent deltas.
+// Run will exit when the context is canceled.
+func (r *Reflector) RunWithContext(ctx context.Context) {
+	logger := klog.FromContext(ctx)
+	logger.V(3).Info("Starting reflector", "type", r.typeDescription, "resyncPeriod", r.resyncPeriod, "reflector", r.name)
 	wait.BackoffUntil(func() {
-		if err := r.ListAndWatch(stopCh); err != nil {
+		if err := r.ListAndWatchWithContext(ctx); err != nil {
-			r.watchErrorHandler(r, err)
+			r.watchErrorHandler(ctx, r, err)
 		}
-	}, r.backoffManager, true, stopCh)
+	}, r.backoffManager, true, ctx.Done())
-	klog.V(3).Infof("Stopping reflector %s (%s) from %s", r.typeDescription, r.resyncPeriod, r.name)
+	logger.V(3).Info("Stopping reflector", "type", r.typeDescription, "resyncPeriod", r.resyncPeriod, "reflector", r.name)
 }
 
 var (
@@ -345,21 +367,31 @@ func (r *Reflector) resyncChan() (<-chan time.Time, func() bool) {
 // ListAndWatch first lists all items and get the resource version at the moment of call,
 // and then use the resource version to watch.
 // It returns error if ListAndWatch didn't even try to initialize watch.
+//
+// Contextual logging: ListAndWatchWithContext should be used instead of ListAndWatch in code which supports contextual logging.
 func (r *Reflector) ListAndWatch(stopCh <-chan struct{}) error {
-	klog.V(3).Infof("Listing and watching %v from %s", r.typeDescription, r.name)
+	return r.ListAndWatchWithContext(wait.ContextForChannel(stopCh))
+}
+
+// ListAndWatchWithContext first lists all items and get the resource version at the moment of call,
+// and then use the resource version to watch.
+// It returns error if ListAndWatchWithContext didn't even try to initialize watch.
+func (r *Reflector) ListAndWatchWithContext(ctx context.Context) error {
+	logger := klog.FromContext(ctx)
+	logger.V(3).Info("Listing and watching", "type", r.typeDescription, "reflector", r.name)
 	var err error
 	var w watch.Interface
 	useWatchList := ptr.Deref(r.UseWatchList, false)
 	fallbackToList := !useWatchList
 
 	if useWatchList {
-		w, err = r.watchList(stopCh)
+		w, err = r.watchList(ctx)
 		if w == nil && err == nil {
 			// stopCh was closed
 			return nil
 		}
 		if err != nil {
-			klog.Warningf("The watchlist request ended with an error, falling back to the standard LIST/WATCH semantics because making progress is better than deadlocking, err = %v", err)
+			logger.Error(err, "The watchlist request ended with an error, falling back to the standard LIST/WATCH semantics because making progress is better than deadlocking")
 			fallbackToList = true
 			// ensure that we won't accidentally pass some garbage down the watch.
 			w = nil
@@ -367,20 +399,21 @@ func (r *Reflector) ListAndWatch(stopCh <-chan struct{}) error {
 	}
 
 	if fallbackToList {
-		err = r.list(stopCh)
+		err = r.list(ctx)
 		if err != nil {
 			return err
 		}
 	}
 
-	klog.V(2).Infof("Caches populated for %v from %s", r.typeDescription, r.name)
+	logger.V(2).Info("Caches populated", "type", r.typeDescription, "reflector", r.name)
-	return r.watchWithResync(w, stopCh)
+	return r.watchWithResync(ctx, w)
 }
 
 // startResync periodically calls r.store.Resync() method.
 // Note that this method is blocking and should be
 // called in a separate goroutine.
-func (r *Reflector) startResync(stopCh <-chan struct{}, cancelCh <-chan struct{}, resyncerrc chan error) {
+func (r *Reflector) startResync(ctx context.Context, resyncerrc chan error) {
+	logger := klog.FromContext(ctx)
 	resyncCh, cleanup := r.resyncChan()
 	defer func() {
 		cleanup() // Call the last one written into cleanup
@@ -388,13 +421,11 @@ func (r *Reflector) startResync(stopCh <-chan struct{}, cancelCh <-chan struct{}
 	for {
 		select {
 		case <-resyncCh:
-		case <-stopCh:
+		case <-ctx.Done():
-			return
-		case <-cancelCh:
 			return
 		}
 		if r.ShouldResync == nil || r.ShouldResync() {
-			klog.V(4).Infof("%s: forcing resync", r.name)
+			logger.V(4).Info("Forcing resync", "reflector", r.name)
 			if err := r.store.Resync(); err != nil {
 				resyncerrc <- err
 				return
@@ -406,16 +437,27 @@ func (r *Reflector) startResync(stopCh <-chan struct{}, cancelCh <-chan struct{}
 }
 
 // watchWithResync runs watch with startResync in the background.
-func (r *Reflector) watchWithResync(w watch.Interface, stopCh <-chan struct{}) error {
+func (r *Reflector) watchWithResync(ctx context.Context, w watch.Interface) error {
 	resyncerrc := make(chan error, 1)
-	cancelCh := make(chan struct{})
+	cancelCtx, cancel := context.WithCancel(ctx)
-	defer close(cancelCh)
+	// Waiting for completion of the goroutine is relevant for race detector.
-	go r.startResync(stopCh, cancelCh, resyncerrc)
+	// Without this, there is a race between "this function returns + code
-	return r.watch(w, stopCh, resyncerrc)
+	// waiting for it" and "goroutine does something".
+	var wg wait.Group
+	defer func() {
+		cancel()
+		wg.Wait()
+	}()
+	wg.Start(func() {
+		r.startResync(cancelCtx, resyncerrc)
+	})
+	return r.watch(ctx, w, resyncerrc)
 }
 
 // watch simply starts a watch request with the server.
-func (r *Reflector) watch(w watch.Interface, stopCh <-chan struct{}, resyncerrc chan error) error {
+func (r *Reflector) watch(ctx context.Context, w watch.Interface, resyncerrc chan error) error {
+	stopCh := ctx.Done()
+	logger := klog.FromContext(ctx)
 	var err error
 	retry := NewRetryWithDeadline(r.MaxInternalErrorRetryDuration, time.Minute, apierrors.IsInternalError, r.clock)
 
@@ -451,7 +493,7 @@ func (r *Reflector) watch(w watch.Interface, stopCh <-chan struct{}, resyncerrc
 			w, err = r.listerWatcher.Watch(options)
 			if err != nil {
 				if canRetry := isWatchErrorRetriable(err); canRetry {
-					klog.V(4).Infof("%s: watch of %v returned %v - backing off", r.name, r.typeDescription, err)
+					logger.V(4).Info("Watch failed - backing off", "reflector", r.name, "type", r.typeDescription, "err", err)
 					select {
 					case <-stopCh:
 						return nil
@@ -463,8 +505,8 @@ func (r *Reflector) watch(w watch.Interface, stopCh <-chan struct{}, resyncerrc
 			}
 		}
 
-		err = handleWatch(start, w, r.store, r.expectedType, r.expectedGVK, r.name, r.typeDescription, r.setLastSyncResourceVersion,
+		err = handleWatch(ctx, start, w, r.store, r.expectedType, r.expectedGVK, r.name, r.typeDescription, r.setLastSyncResourceVersion,
-			r.clock, resyncerrc, stopCh)
+			r.clock, resyncerrc)
 		// Ensure that watch will not be reused across iterations.
 		w.Stop()
 		w = nil
@@ -476,9 +518,9 @@ func (r *Reflector) watch(w watch.Interface, stopCh <-chan struct{}, resyncerrc
 					// Don't set LastSyncResourceVersionUnavailable - LIST call with ResourceVersion=RV already
 					// has a semantic that it returns data at least as fresh as provided RV.
 					// So first try to LIST with setting RV to resource version of last observed object.
-					klog.V(4).Infof("%s: watch of %v closed with: %v", r.name, r.typeDescription, err)
+					logger.V(4).Info("Watch closed", "reflector", r.name, "type", r.typeDescription, "err", err)
 				case apierrors.IsTooManyRequests(err):
-					klog.V(2).Infof("%s: watch of %v returned 429 - backing off", r.name, r.typeDescription)
+					logger.V(2).Info("Watch returned 429 - backing off", "reflector", r.name, "type", r.typeDescription)
 					select {
 					case <-stopCh:
 						return nil
@@ -486,10 +528,10 @@ func (r *Reflector) watch(w watch.Interface, stopCh <-chan struct{}, resyncerrc
 						continue
 					}
 				case apierrors.IsInternalError(err) && retry.ShouldRetry():
-					klog.V(2).Infof("%s: retrying watch of %v internal error: %v", r.name, r.typeDescription, err)
+					logger.V(2).Info("Retrying watch after internal error", "reflector", r.name, "type", r.typeDescription, "err", err)
 					continue
 				default:
-					klog.Warningf("%s: watch of %v ended with: %v", r.name, r.typeDescription, err)
+					logger.Info("Warning: watch ended with error", "reflector", r.name, "type", r.typeDescription, "err", err)
 				}
 			}
 			return nil
@@ -499,7 +541,7 @@ func (r *Reflector) watch(w watch.Interface, stopCh <-chan struct{}, resyncerrc
 
 // list simply lists all items and records a resource version obtained from the server at the moment of the call.
 // the resource version can be used for further progress notification (aka. watch).
-func (r *Reflector) list(stopCh <-chan struct{}) error {
+func (r *Reflector) list(ctx context.Context) error {
 	var resourceVersion string
 	options := metav1.ListOptions{ResourceVersion: r.relistResourceVersion()}
 
@@ -558,7 +600,7 @@ func (r *Reflector) list(stopCh <-chan struct{}) error {
 		close(listCh)
 	}()
 	select {
-	case <-stopCh:
+	case <-ctx.Done():
 		return nil
 	case r := <-panicCh:
 		panic(r)
@@ -566,7 +608,6 @@ func (r *Reflector) list(stopCh <-chan struct{}) error {
 	}
 	initTrace.Step("Objects listed", trace.Field{Key: "error", Value: err})
 	if err != nil {
-		klog.Warningf("%s: failed to list %v: %v", r.name, r.typeDescription, err)
 		return fmt.Errorf("failed to list %v: %w", r.typeDescription, err)
 	}
 
@@ -624,7 +665,9 @@ func (r *Reflector) list(stopCh <-chan struct{}) error {
 // After receiving a "Bookmark" event the reflector is considered to be synchronized.
 // It replaces its internal store with the collected items and
 // reuses the current watch requests for getting further events.
-func (r *Reflector) watchList(stopCh <-chan struct{}) (watch.Interface, error) {
+func (r *Reflector) watchList(ctx context.Context) (watch.Interface, error) {
+	stopCh := ctx.Done()
+	logger := klog.FromContext(ctx)
 	var w watch.Interface
 	var err error
 	var temporaryStore Store
@@ -634,7 +677,7 @@ func (r *Reflector) watchList(stopCh <-chan struct{}) (watch.Interface, error) {
 	//  could be unified with the r.watch method
 	isErrorRetriableWithSideEffectsFn := func(err error) bool {
 		if canRetry := isWatchErrorRetriable(err); canRetry {
-			klog.V(2).Infof("%s: watch-list of %v returned %v - backing off", r.name, r.typeDescription, err)
+			logger.V(2).Info("watch-list failed - backing off", "reflector", r.name, "type", r.typeDescription, "err", err)
 			<-r.backoffManager.Backoff().C()
 			return true
 		}
@@ -681,9 +724,9 @@ func (r *Reflector) watchList(stopCh <-chan struct{}) (watch.Interface, error) {
 			}
 			return nil, err
 		}
-		watchListBookmarkReceived, err := handleListWatch(start, w, temporaryStore, r.expectedType, r.expectedGVK, r.name, r.typeDescription,
+		watchListBookmarkReceived, err := handleListWatch(ctx, start, w, temporaryStore, r.expectedType, r.expectedGVK, r.name, r.typeDescription,
 			func(rv string) { resourceVersion = rv },
-			r.clock, make(chan error), stopCh)
+			r.clock, make(chan error))
 		if err != nil {
 			w.Stop() // stop and retry with clean state
 			if errors.Is(err, errorStopRequested) {
@@ -706,7 +749,7 @@ func (r *Reflector) watchList(stopCh <-chan struct{}) (watch.Interface, error) {
 	// we utilize the temporaryStore to ensure independence from the current store implementation.
 	// as of today, the store is implemented as a queue and will be drained by the higher-level
 	// component as soon as it finishes replacing the content.
-	checkWatchListDataConsistencyIfRequested(wait.ContextForChannel(stopCh), r.name, resourceVersion, wrapListFuncWithContext(r.listerWatcher.List), temporaryStore.List)
+	checkWatchListDataConsistencyIfRequested(ctx, r.name, resourceVersion, wrapListFuncWithContext(r.listerWatcher.List), temporaryStore.List)
 
 	if err := r.store.Replace(temporaryStore.List(), resourceVersion); err != nil {
 		return nil, fmt.Errorf("unable to sync watch-list result: %w", err)
@@ -731,6 +774,7 @@ func (r *Reflector) syncWith(items []runtime.Object, resourceVersion string) err
 // retry. If successful, the watcher will be left open after receiving the
 // initial set of objects, to allow watching for future events.
 func handleListWatch(
+	ctx context.Context,
 	start time.Time,
 	w watch.Interface,
 	store Store,
@@ -741,17 +785,17 @@ func handleListWatch(
 	setLastSyncResourceVersion func(string),
 	clock clock.Clock,
 	errCh chan error,
-	stopCh <-chan struct{},
 ) (bool, error) {
 	exitOnWatchListBookmarkReceived := true
-	return handleAnyWatch(start, w, store, expectedType, expectedGVK, name, expectedTypeName,
+	return handleAnyWatch(ctx, start, w, store, expectedType, expectedGVK, name, expectedTypeName,
-		setLastSyncResourceVersion, exitOnWatchListBookmarkReceived, clock, errCh, stopCh)
+		setLastSyncResourceVersion, exitOnWatchListBookmarkReceived, clock, errCh)
 }
 
 // handleListWatch consumes events from w, updates the Store, and records the
 // last seen ResourceVersion, to allow continuing from that ResourceVersion on
 // retry. The watcher will always be stopped on exit.
 func handleWatch(
+	ctx context.Context,
 	start time.Time,
 	w watch.Interface,
 	store Store,
@@ -762,11 +806,10 @@ func handleWatch(
 	setLastSyncResourceVersion func(string),
 	clock clock.Clock,
 	errCh chan error,
-	stopCh <-chan struct{},
 ) error {
 	exitOnWatchListBookmarkReceived := false
-	_, err := handleAnyWatch(start, w, store, expectedType, expectedGVK, name, expectedTypeName,
+	_, err := handleAnyWatch(ctx, start, w, store, expectedType, expectedGVK, name, expectedTypeName,
-		setLastSyncResourceVersion, exitOnWatchListBookmarkReceived, clock, errCh, stopCh)
+		setLastSyncResourceVersion, exitOnWatchListBookmarkReceived, clock, errCh)
 	return err
 }
 
@@ -779,7 +822,9 @@ func handleWatch(
 // The watcher will always be stopped, unless exitOnWatchListBookmarkReceived is
 // true and watchListBookmarkReceived is true. This allows the same watch stream
 // to be re-used by the caller to continue watching for new events.
-func handleAnyWatch(start time.Time,
+func handleAnyWatch(
+	ctx context.Context,
+	start time.Time,
 	w watch.Interface,
 	store Store,
 	expectedType reflect.Type,
@@ -790,17 +835,17 @@ func handleAnyWatch(start time.Time,
 	exitOnWatchListBookmarkReceived bool,
 	clock clock.Clock,
 	errCh chan error,
-	stopCh <-chan struct{},
 ) (bool, error) {
 	watchListBookmarkReceived := false
 	eventCount := 0
-	initialEventsEndBookmarkWarningTicker := newInitialEventsEndBookmarkTicker(name, clock, start, exitOnWatchListBookmarkReceived)
+	logger := klog.FromContext(ctx)
+	initialEventsEndBookmarkWarningTicker := newInitialEventsEndBookmarkTicker(logger, name, clock, start, exitOnWatchListBookmarkReceived)
 	defer initialEventsEndBookmarkWarningTicker.Stop()
 
 loop:
 	for {
 		select {
-		case <-stopCh:
+		case <-ctx.Done():
 			return watchListBookmarkReceived, errorStopRequested
 		case err := <-errCh:
 			return watchListBookmarkReceived, err
@@ -813,19 +858,19 @@ loop:
 			}
 			if expectedType != nil {
 				if e, a := expectedType, reflect.TypeOf(event.Object); e != a {
-					utilruntime.HandleError(fmt.Errorf("%s: expected type %v, but watch event object had type %v", name, e, a))
+					utilruntime.HandleErrorWithContext(ctx, nil, "Unexpected watch event object type", "reflector", name, "expectedType", e, "actualType", a)
 					continue
 				}
 			}
 			if expectedGVK != nil {
 				if e, a := *expectedGVK, event.Object.GetObjectKind().GroupVersionKind(); e != a {
-					utilruntime.HandleError(fmt.Errorf("%s: expected gvk %v, but watch event object had gvk %v", name, e, a))
+					utilruntime.HandleErrorWithContext(ctx, nil, "Unexpected watch event object gvk", "reflector", name, "expectedGVK", e, "actualGVK", a)
 					continue
 				}
 			}
 			meta, err := meta.Accessor(event.Object)
 			if err != nil {
-				utilruntime.HandleError(fmt.Errorf("%s: unable to understand watch event %#v", name, event))
+				utilruntime.HandleErrorWithContext(ctx, err, "Unable to understand watch event", "reflector", name, "event", event)
 				continue
 			}
 			resourceVersion := meta.GetResourceVersion()
@@ -833,12 +878,12 @@ loop:
 			case watch.Added:
 				err := store.Add(event.Object)
 				if err != nil {
-					utilruntime.HandleError(fmt.Errorf("%s: unable to add watch event object (%#v) to store: %v", name, event.Object, err))
+					utilruntime.HandleErrorWithContext(ctx, err, "Unable to add watch event object to store", "reflector", name, "object", event.Object)
 				}
 			case watch.Modified:
 				err := store.Update(event.Object)
 				if err != nil {
-					utilruntime.HandleError(fmt.Errorf("%s: unable to update watch event object (%#v) to store: %v", name, event.Object, err))
+					utilruntime.HandleErrorWithContext(ctx, err, "Unable to update watch event object to store", "reflector", name, "object", event.Object)
 				}
 			case watch.Deleted:
 				// TODO: Will any consumers need access to the "last known
@@ -846,7 +891,7 @@ loop:
 				// to change this.
 				err := store.Delete(event.Object)
 				if err != nil {
-					utilruntime.HandleError(fmt.Errorf("%s: unable to delete watch event object (%#v) from store: %v", name, event.Object, err))
+					utilruntime.HandleErrorWithContext(ctx, err, "Unable to delete watch event object from store", "reflector", name, "object", event.Object)
 				}
 			case watch.Bookmark:
 				// A `Bookmark` means watch has synced here, just update the resourceVersion
@@ -854,7 +899,7 @@ loop:
 					watchListBookmarkReceived = true
 				}
 			default:
-				utilruntime.HandleError(fmt.Errorf("%s: unable to understand watch event %#v", name, event))
+				utilruntime.HandleErrorWithContext(ctx, err, "Unknown watch event", "reflector", name, "event", event)
 			}
 			setLastSyncResourceVersion(resourceVersion)
 			if rvu, ok := store.(ResourceVersionUpdater); ok {
@@ -863,7 +908,7 @@ loop:
 			eventCount++
 			if exitOnWatchListBookmarkReceived && watchListBookmarkReceived {
 				watchDuration := clock.Since(start)
-				klog.V(4).Infof("exiting %v Watch because received the bookmark that marks the end of initial events stream, total %v items received in %v", name, eventCount, watchDuration)
+				klog.FromContext(ctx).V(4).Info("Exiting watch because received the bookmark that marks the end of initial events stream", "reflector", name, "totalItems", eventCount, "duration", watchDuration)
 				return watchListBookmarkReceived, nil
 			}
 			initialEventsEndBookmarkWarningTicker.observeLastEventTimeStamp(clock.Now())
@@ -876,7 +921,7 @@ loop:
 	if watchDuration < 1*time.Second && eventCount == 0 {
 		return watchListBookmarkReceived, fmt.Errorf("very short watch: %s: Unexpected watch close - watch lasted less than a second and no items received", name)
 	}
-	klog.V(4).Infof("%s: Watch close - %v total %v items received", name, expectedTypeName, eventCount)
+	klog.FromContext(ctx).V(4).Info("Watch close", "reflector", name, "type", expectedTypeName, "totalItems", eventCount)
 	return watchListBookmarkReceived, nil
 }
 
@@ -1006,6 +1051,7 @@ type initialEventsEndBookmarkTicker struct {
 	clock.Ticker
 	clock  clock.Clock
 	name   string
+	logger klog.Logger
 
 	watchStart           time.Time
 	tickInterval         time.Duration
@@ -1019,15 +1065,15 @@ type initialEventsEndBookmarkTicker struct {
 // Note that the caller controls whether to call t.C() and t.Stop().
 //
 // In practice, the reflector exits the watchHandler as soon as the bookmark event is received and calls the t.C() method.
-func newInitialEventsEndBookmarkTicker(name string, c clock.Clock, watchStart time.Time, exitOnWatchListBookmarkReceived bool) *initialEventsEndBookmarkTicker {
+func newInitialEventsEndBookmarkTicker(logger klog.Logger, name string, c clock.Clock, watchStart time.Time, exitOnWatchListBookmarkReceived bool) *initialEventsEndBookmarkTicker {
-	return newInitialEventsEndBookmarkTickerInternal(name, c, watchStart, 10*time.Second, exitOnWatchListBookmarkReceived)
+	return newInitialEventsEndBookmarkTickerInternal(logger, name, c, watchStart, 10*time.Second, exitOnWatchListBookmarkReceived)
 }
 
-func newInitialEventsEndBookmarkTickerInternal(name string, c clock.Clock, watchStart time.Time, tickInterval time.Duration, exitOnWatchListBookmarkReceived bool) *initialEventsEndBookmarkTicker {
+func newInitialEventsEndBookmarkTickerInternal(logger klog.Logger, name string, c clock.Clock, watchStart time.Time, tickInterval time.Duration, exitOnWatchListBookmarkReceived bool) *initialEventsEndBookmarkTicker {
 	clockWithTicker, ok := c.(clock.WithTicker)
 	if !ok || !exitOnWatchListBookmarkReceived {
 		if exitOnWatchListBookmarkReceived {
-			klog.Warningf("clock does not support WithTicker interface but exitOnInitialEventsEndBookmark was requested")
+			logger.Info("Warning: clock does not support WithTicker interface but exitOnInitialEventsEndBookmark was requested")
 		}
 		return &initialEventsEndBookmarkTicker{
 			Ticker: &noopTicker{},
@@ -1038,6 +1084,7 @@ func newInitialEventsEndBookmarkTickerInternal(name string, c clock.Clock, watch
 		Ticker:       clockWithTicker.NewTicker(tickInterval),
 		clock:        c,
 		name:         name,
+		logger:       logger,
 		watchStart:   watchStart,
 		tickInterval: tickInterval,
 	}
@@ -1049,7 +1096,7 @@ func (t *initialEventsEndBookmarkTicker) observeLastEventTimeStamp(lastEventObse
 
 func (t *initialEventsEndBookmarkTicker) warnIfExpired() {
 	if err := t.produceWarningIfExpired(); err != nil {
-		klog.Warning(err)
+		t.logger.Info("Warning: event bookmark expired", "err", err)
 	}
 }
 

tools/cache/reflector_test.go

@@ -45,6 +45,7 @@ import (
 	"k8s.io/apimachinery/pkg/util/sets"
 	"k8s.io/apimachinery/pkg/util/wait"
 	"k8s.io/apimachinery/pkg/watch"
+	"k8s.io/klog/v2/ktesting"
 	"k8s.io/utils/clock"
 	testingclock "k8s.io/utils/clock/testing"
 )
@@ -64,6 +65,7 @@ func (t *testLW) Watch(options metav1.ListOptions) (watch.Interface, error) {
 }
 
 func TestCloseWatchChannelOnError(t *testing.T) {
+	_, ctx := ktesting.NewTestContext(t)
 	r := NewReflector(&testLW{}, &v1.Pod{}, NewStore(MetaNamespaceKeyFunc), 0)
 	pod := &v1.Pod{ObjectMeta: metav1.ObjectMeta{Name: "bar"}}
 	fw := watch.NewFake()
@@ -75,7 +77,7 @@ func TestCloseWatchChannelOnError(t *testing.T) {
 			return &v1.PodList{ListMeta: metav1.ListMeta{ResourceVersion: "1"}}, nil
 		},
 	}
-	go r.ListAndWatch(wait.NeverStop)
+	go func() { assert.NoError(t, r.ListAndWatchWithContext(ctx)) }()
 	fw.Error(pod)
 	select {
 	case _, ok := <-fw.ResultChan():
@@ -89,7 +91,8 @@ func TestCloseWatchChannelOnError(t *testing.T) {
 }
 
 func TestRunUntil(t *testing.T) {
-	stopCh := make(chan struct{})
+	_, ctx := ktesting.NewTestContext(t)
+	ctx, cancel := context.WithCancelCause(ctx)
 	store := NewStore(MetaNamespaceKeyFunc)
 	r := NewReflector(&testLW{}, &v1.Pod{}, store, 0)
 	fw := watch.NewFake()
@@ -104,13 +107,13 @@ func TestRunUntil(t *testing.T) {
 	doneCh := make(chan struct{})
 	go func() {
 		defer close(doneCh)
-		r.Run(stopCh)
+		r.RunWithContext(ctx)
 	}()
 	// Synchronously add a dummy pod into the watch channel so we
 	// know the RunUntil go routine is in the watch handler.
 	fw.Add(&v1.Pod{ObjectMeta: metav1.ObjectMeta{Name: "bar"}})
 
-	close(stopCh)
+	cancel(errors.New("done"))
 	resultCh := fw.ResultChan()
 	for {
 		select {
@@ -149,8 +152,9 @@ func TestReflectorResyncChan(t *testing.T) {
 // TestReflectorWatchStoppedBefore ensures that neither List nor Watch are
 // called if the stop channel is closed before Reflector.watch is called.
 func TestReflectorWatchStoppedBefore(t *testing.T) {
-	stopCh := make(chan struct{})
+	_, ctx := ktesting.NewTestContext(t)
-	close(stopCh)
+	ctx, cancel := context.WithCancelCause(ctx)
+	cancel(errors.New("don't run"))
 
 	lw := &ListWatch{
 		ListFunc: func(_ metav1.ListOptions) (runtime.Object, error) {
@@ -165,14 +169,15 @@ func TestReflectorWatchStoppedBefore(t *testing.T) {
 	}
 	target := NewReflector(lw, &v1.Pod{}, nil, 0)
 
-	err := target.watch(nil, stopCh, nil)
+	err := target.watch(ctx, nil, nil)
 	require.NoError(t, err)
 }
 
 // TestReflectorWatchStoppedAfter ensures that neither the watcher is stopped if
 // the stop channel is closed after Reflector.watch has started watching.
 func TestReflectorWatchStoppedAfter(t *testing.T) {
-	stopCh := make(chan struct{})
+	_, ctx := ktesting.NewTestContext(t)
+	ctx, cancel := context.WithCancelCause(ctx)
 
 	var watchers []*watch.FakeWatcher
 
@@ -185,7 +190,7 @@ func TestReflectorWatchStoppedAfter(t *testing.T) {
 			// Simulate the stop channel being closed after watching has started
 			go func() {
 				time.Sleep(10 * time.Millisecond)
-				close(stopCh)
+				cancel(errors.New("10ms timeout reached"))
 			}()
 			// Use a fake watcher that never sends events
 			w := watch.NewFake()
@@ -195,7 +200,7 @@ func TestReflectorWatchStoppedAfter(t *testing.T) {
 	}
 	target := NewReflector(lw, &v1.Pod{}, nil, 0)
 
-	err := target.watch(nil, stopCh, nil)
+	err := target.watch(ctx, nil, nil)
 	require.NoError(t, err)
 	require.Len(t, watchers, 1)
 	require.True(t, watchers[0].IsStopped())
@@ -219,9 +224,10 @@ func BenchmarkReflectorResyncChanMany(b *testing.B) {
 func TestReflectorHandleWatchStoppedBefore(t *testing.T) {
 	s := NewStore(MetaNamespaceKeyFunc)
 	g := NewReflector(&testLW{}, &v1.Pod{}, s, 0)
-	stopCh := make(chan struct{})
+	_, ctx := ktesting.NewTestContext(t)
-	// Simulate the watch channel being closed before the watchHandler is called
+	ctx, cancel := context.WithCancelCause(ctx)
-	close(stopCh)
+	// Simulate the context being canceled before the watchHandler is called
+	cancel(errors.New("don't run"))
 	var calls []string
 	resultCh := make(chan watch.Event)
 	fw := watch.MockWatcher{
@@ -234,7 +240,7 @@ func TestReflectorHandleWatchStoppedBefore(t *testing.T) {
 			return resultCh
 		},
 	}
-	err := handleWatch(time.Now(), fw, s, g.expectedType, g.expectedGVK, g.name, g.typeDescription, g.setLastSyncResourceVersion, g.clock, nevererrc, stopCh)
+	err := handleWatch(ctx, time.Now(), fw, s, g.expectedType, g.expectedGVK, g.name, g.typeDescription, g.setLastSyncResourceVersion, g.clock, nevererrc)
 	if err == nil {
 		t.Errorf("unexpected non-error")
 	}
@@ -251,7 +257,8 @@ func TestReflectorHandleWatchStoppedAfter(t *testing.T) {
 	s := NewStore(MetaNamespaceKeyFunc)
 	g := NewReflector(&testLW{}, &v1.Pod{}, s, 0)
 	var calls []string
-	stopCh := make(chan struct{})
+	_, ctx := ktesting.NewTestContext(t)
+	ctx, cancel := context.WithCancelCause(ctx)
 	resultCh := make(chan watch.Event)
 	fw := watch.MockWatcher{
 		StopFunc: func() {
@@ -265,12 +272,12 @@ func TestReflectorHandleWatchStoppedAfter(t *testing.T) {
 			// caller, after watching has started.
 			go func() {
 				time.Sleep(10 * time.Millisecond)
-				close(stopCh)
+				cancel(errors.New("10ms timeout reached"))
 			}()
 			return resultCh
 		},
 	}
-	err := handleWatch(time.Now(), fw, s, g.expectedType, g.expectedGVK, g.name, g.typeDescription, g.setLastSyncResourceVersion, g.clock, nevererrc, stopCh)
+	err := handleWatch(ctx, time.Now(), fw, s, g.expectedType, g.expectedGVK, g.name, g.typeDescription, g.setLastSyncResourceVersion, g.clock, nevererrc)
 	if err == nil {
 		t.Errorf("unexpected non-error")
 	}
@@ -285,6 +292,7 @@ func TestReflectorHandleWatchStoppedAfter(t *testing.T) {
 func TestReflectorHandleWatchResultChanClosedBefore(t *testing.T) {
 	s := NewStore(MetaNamespaceKeyFunc)
 	g := NewReflector(&testLW{}, &v1.Pod{}, s, 0)
+	_, ctx := ktesting.NewTestContext(t)
 	var calls []string
 	resultCh := make(chan watch.Event)
 	fw := watch.MockWatcher{
@@ -298,7 +306,7 @@ func TestReflectorHandleWatchResultChanClosedBefore(t *testing.T) {
 	}
 	// Simulate the result channel being closed by the producer before handleWatch is called.
 	close(resultCh)
-	err := handleWatch(time.Now(), fw, s, g.expectedType, g.expectedGVK, g.name, g.typeDescription, g.setLastSyncResourceVersion, g.clock, nevererrc, wait.NeverStop)
+	err := handleWatch(ctx, time.Now(), fw, s, g.expectedType, g.expectedGVK, g.name, g.typeDescription, g.setLastSyncResourceVersion, g.clock, nevererrc)
 	if err == nil {
 		t.Errorf("unexpected non-error")
 	}
@@ -313,6 +321,7 @@ func TestReflectorHandleWatchResultChanClosedBefore(t *testing.T) {
 func TestReflectorHandleWatchResultChanClosedAfter(t *testing.T) {
 	s := NewStore(MetaNamespaceKeyFunc)
 	g := NewReflector(&testLW{}, &v1.Pod{}, s, 0)
+	_, ctx := ktesting.NewTestContext(t)
 	var calls []string
 	resultCh := make(chan watch.Event)
 	fw := watch.MockWatcher{
@@ -331,7 +340,7 @@ func TestReflectorHandleWatchResultChanClosedAfter(t *testing.T) {
 			return resultCh
 		},
 	}
-	err := handleWatch(time.Now(), fw, s, g.expectedType, g.expectedGVK, g.name, g.typeDescription, g.setLastSyncResourceVersion, g.clock, nevererrc, wait.NeverStop)
+	err := handleWatch(ctx, time.Now(), fw, s, g.expectedType, g.expectedGVK, g.name, g.typeDescription, g.setLastSyncResourceVersion, g.clock, nevererrc)
 	if err == nil {
 		t.Errorf("unexpected non-error")
 	}
@@ -348,11 +357,12 @@ func TestReflectorWatchHandler(t *testing.T) {
 	// watching after all the events have been consumed. This avoids race
 	// conditions which can happen if the producer calls Stop(), instead of the
 	// consumer.
-	stopCh := make(chan struct{})
+	_, ctx := ktesting.NewTestContext(t)
+	ctx, cancel := context.WithCancelCause(ctx)
 	setLastSyncResourceVersion := func(rv string) {
 		g.setLastSyncResourceVersion(rv)
 		if rv == "32" {
-			close(stopCh)
+			cancel(errors.New("LastSyncResourceVersion is 32"))
 		}
 	}
 	fw := watch.NewFake()
@@ -365,7 +375,7 @@ func TestReflectorWatchHandler(t *testing.T) {
 		fw.Add(&v1.Pod{ObjectMeta: metav1.ObjectMeta{Name: "baz", ResourceVersion: "32"}})
 		fw.Stop()
 	}()
-	err := handleWatch(time.Now(), fw, s, g.expectedType, g.expectedGVK, g.name, g.typeDescription, setLastSyncResourceVersion, g.clock, nevererrc, stopCh)
+	err := handleWatch(ctx, time.Now(), fw, s, g.expectedType, g.expectedGVK, g.name, g.typeDescription, setLastSyncResourceVersion, g.clock, nevererrc)
 	// TODO(karlkfi): Fix FakeWatcher to avoid race condition between watcher.Stop() & close(stopCh)
 	if err != nil && !errors.Is(err, errorStopRequested) {
 		t.Errorf("unexpected error %v", err)
@@ -408,15 +418,19 @@ func TestReflectorStopWatch(t *testing.T) {
 	s := NewStore(MetaNamespaceKeyFunc)
 	g := NewReflector(&testLW{}, &v1.Pod{}, s, 0)
 	fw := watch.NewFake()
-	stopWatch := make(chan struct{})
+	_, ctx := ktesting.NewTestContext(t)
-	close(stopWatch)
+	ctx, cancel := context.WithCancelCause(ctx)
-	err := handleWatch(time.Now(), fw, s, g.expectedType, g.expectedGVK, g.name, g.typeDescription, g.setLastSyncResourceVersion, g.clock, nevererrc, stopWatch)
+	cancel(errors.New("don't run"))
+	err := handleWatch(ctx, time.Now(), fw, s, g.expectedType, g.expectedGVK, g.name, g.typeDescription, g.setLastSyncResourceVersion, g.clock, nevererrc)
 	if err != errorStopRequested {
 		t.Errorf("expected stop error, got %q", err)
 	}
 }
 
 func TestReflectorListAndWatch(t *testing.T) {
+	_, ctx := ktesting.NewTestContext(t)
+	ctx, cancel := context.WithCancel(ctx)
+	defer cancel()
 	createdFakes := make(chan *watch.FakeWatcher)
 
 	// The ListFunc says that it's at revision 1. Therefore, we expect our WatchFunc
@@ -442,7 +456,7 @@ func TestReflectorListAndWatch(t *testing.T) {
 	}
 	s := NewFIFO(MetaNamespaceKeyFunc)
 	r := NewReflector(lw, &v1.Pod{}, s, 0)
-	go r.ListAndWatch(wait.NeverStop)
+	go func() { assert.NoError(t, r.ListAndWatchWithContext(ctx)) }()
 
 	ids := []string{"foo", "bar", "baz", "qux", "zoo"}
 	var fw *watch.FakeWatcher
@@ -539,7 +553,8 @@ func TestReflectorListAndWatchWithErrors(t *testing.T) {
 			}
 		}
 		watchRet, watchErr := item.events, item.watchErr
-		stopCh := make(chan struct{})
+		_, ctx := ktesting.NewTestContext(t)
+		ctx, cancel := context.WithCancelCause(ctx)
 		lw := &testLW{
 			WatchFunc: func(options metav1.ListOptions) (watch.Interface, error) {
 				if watchErr != nil {
@@ -557,7 +572,7 @@ func TestReflectorListAndWatchWithErrors(t *testing.T) {
 					// result channel, and wait for the consumer to stop the
 					// watcher, to avoid race conditions.
 					// TODO: Fix the FakeWatcher to separate watcher.Stop from close(resultCh)
-					close(stopCh)
+					cancel(errors.New("done"))
 				}()
 				return fw, nil
 			},
@@ -566,7 +581,7 @@ func TestReflectorListAndWatchWithErrors(t *testing.T) {
 			},
 		}
 		r := NewReflector(lw, &v1.Pod{}, s, 0)
-		err := r.ListAndWatch(stopCh)
+		err := r.ListAndWatchWithContext(ctx)
 		if item.listErr != nil && !errors.Is(err, item.listErr) {
 			t.Errorf("unexpected ListAndWatch error: %v", err)
 		}
@@ -593,7 +608,8 @@ func TestReflectorListAndWatchInitConnBackoff(t *testing.T) {
 	for _, test := range table {
 		t.Run(fmt.Sprintf("%d connection failures takes at least %d ms", test.numConnFails, 1<<test.numConnFails),
 			func(t *testing.T) {
-				stopCh := make(chan struct{})
+				_, ctx := ktesting.NewTestContext(t)
+				ctx, cancel := context.WithCancelCause(ctx)
 				connFails := test.numConnFails
 				fakeClock := testingclock.NewFakeClock(time.Unix(0, 0))
 				bm := wait.NewExponentialBackoffManager(time.Millisecond, maxBackoff, 100*time.Millisecond, 2.0, 1.0, fakeClock)
@@ -624,7 +640,7 @@ func TestReflectorListAndWatchInitConnBackoff(t *testing.T) {
 							connFails--
 							return nil, syscall.ECONNREFUSED
 						}
-						close(stopCh)
+						cancel(errors.New("done"))
 						return watch.NewFake(), nil
 					},
 					ListFunc: func(options metav1.ListOptions) (runtime.Object, error) {
@@ -637,10 +653,10 @@ func TestReflectorListAndWatchInitConnBackoff(t *testing.T) {
 					store:             NewFIFO(MetaNamespaceKeyFunc),
 					backoffManager:    bm,
 					clock:             fakeClock,
-					watchErrorHandler: WatchErrorHandler(DefaultWatchErrorHandler),
+					watchErrorHandler: WatchErrorHandlerWithContext(DefaultWatchErrorHandler),
 				}
 				start := fakeClock.Now()
-				err := r.ListAndWatch(stopCh)
+				err := r.ListAndWatchWithContext(ctx)
 				elapsed := fakeClock.Since(start)
 				if err != nil {
 					t.Errorf("unexpected error %v", err)
@@ -666,6 +682,7 @@ func (f *fakeBackoff) Backoff() clock.Timer {
 }
 
 func TestBackoffOnTooManyRequests(t *testing.T) {
+	_, ctx := ktesting.NewTestContext(t)
 	err := apierrors.NewTooManyRequests("too many requests", 1)
 	clock := &clock.RealClock{}
 	bm := &fakeBackoff{clock: clock}
@@ -697,11 +714,11 @@ func TestBackoffOnTooManyRequests(t *testing.T) {
 		store:             NewFIFO(MetaNamespaceKeyFunc),
 		backoffManager:    bm,
 		clock:             clock,
-		watchErrorHandler: WatchErrorHandler(DefaultWatchErrorHandler),
+		watchErrorHandler: WatchErrorHandlerWithContext(DefaultWatchErrorHandler),
 	}
 
 	stopCh := make(chan struct{})
-	if err := r.ListAndWatch(stopCh); err != nil {
+	if err := r.ListAndWatchWithContext(ctx); err != nil {
 		t.Fatal(err)
 	}
 	close(stopCh)
@@ -738,14 +755,15 @@ func TestNoRelistOnTooManyRequests(t *testing.T) {
 		store:             NewFIFO(MetaNamespaceKeyFunc),
 		backoffManager:    bm,
 		clock:             clock,
-		watchErrorHandler: WatchErrorHandler(DefaultWatchErrorHandler),
+		watchErrorHandler: WatchErrorHandlerWithContext(DefaultWatchErrorHandler),
 	}
 
-	stopCh := make(chan struct{})
+	_, ctx := ktesting.NewTestContext(t)
-	if err := r.ListAndWatch(stopCh); err != nil {
+	ctx, cancel := context.WithCancelCause(ctx)
+	if err := r.ListAndWatchWithContext(ctx); err != nil {
 		t.Fatal(err)
 	}
-	close(stopCh)
+	cancel(errors.New("done"))
 	if listCalls != 1 {
 		t.Errorf("unexpected list calls: %d", listCalls)
 	}
@@ -812,14 +830,15 @@ func TestRetryInternalError(t *testing.T) {
 			store:             NewFIFO(MetaNamespaceKeyFunc),
 			backoffManager:    bm,
 			clock:             fakeClock,
-			watchErrorHandler: WatchErrorHandler(DefaultWatchErrorHandler),
+			watchErrorHandler: WatchErrorHandlerWithContext(DefaultWatchErrorHandler),
 		}
 
 		r.MaxInternalErrorRetryDuration = tc.maxInternalDuration
 
-		stopCh := make(chan struct{})
+		_, ctx := ktesting.NewTestContext(t)
-		r.ListAndWatch(stopCh)
+		ctx, cancel := context.WithCancelCause(ctx)
-		close(stopCh)
+		require.NoError(t, r.ListAndWatchWithContext(ctx))
+		cancel(errors.New("done"))
 
 		if counter-1 != tc.wantRetries {
 			t.Errorf("%v unexpected number of retries: %d", tc, counter-1)
@@ -829,7 +848,7 @@ func TestRetryInternalError(t *testing.T) {
 
 func TestReflectorResync(t *testing.T) {
 	iteration := 0
-	stopCh := make(chan struct{})
+	_, ctx := ktesting.NewTestContext(t)
 	rerr := errors.New("expected resync reached")
 	s := &FakeCustomStore{
 		ResyncFunc: func() error {
@@ -852,7 +871,7 @@ func TestReflectorResync(t *testing.T) {
 	}
 	resyncPeriod := 1 * time.Millisecond
 	r := NewReflector(lw, &v1.Pod{}, s, resyncPeriod)
-	if err := r.ListAndWatch(stopCh); err != nil {
+	if err := r.ListAndWatchWithContext(ctx); err != nil {
 		// error from Resync is not propaged up to here.
 		t.Errorf("expected error %v", err)
 	}
@@ -862,13 +881,14 @@ func TestReflectorResync(t *testing.T) {
 }
 
 func TestReflectorWatchListPageSize(t *testing.T) {
-	stopCh := make(chan struct{})
+	_, ctx := ktesting.NewTestContext(t)
+	ctx, cancel := context.WithCancelCause(ctx)
 	s := NewStore(MetaNamespaceKeyFunc)
 
 	lw := &testLW{
 		WatchFunc: func(options metav1.ListOptions) (watch.Interface, error) {
 			// Stop once the reflector begins watching since we're only interested in the list.
-			close(stopCh)
+			cancel(errors.New("done"))
 			fw := watch.NewFake()
 			return fw, nil
 		},
@@ -898,7 +918,7 @@ func TestReflectorWatchListPageSize(t *testing.T) {
 	r.setLastSyncResourceVersion("10")
 	// Set the reflector to paginate the list request in 4 item chunks.
 	r.WatchListPageSize = 4
-	r.ListAndWatch(stopCh)
+	require.NoError(t, r.ListAndWatchWithContext(ctx))
 
 	results := s.List()
 	if len(results) != 10 {
@@ -907,13 +927,14 @@ func TestReflectorWatchListPageSize(t *testing.T) {
 }
 
 func TestReflectorNotPaginatingNotConsistentReads(t *testing.T) {
-	stopCh := make(chan struct{})
+	_, ctx := ktesting.NewTestContext(t)
+	ctx, cancel := context.WithCancelCause(ctx)
 	s := NewStore(MetaNamespaceKeyFunc)
 
 	lw := &testLW{
 		WatchFunc: func(options metav1.ListOptions) (watch.Interface, error) {
 			// Stop once the reflector begins watching since we're only interested in the list.
-			close(stopCh)
+			cancel(errors.New("done"))
 			fw := watch.NewFake()
 			return fw, nil
 		},
@@ -933,7 +954,7 @@ func TestReflectorNotPaginatingNotConsistentReads(t *testing.T) {
 	}
 	r := NewReflector(lw, &v1.Pod{}, s, 0)
 	r.setLastSyncResourceVersion("10")
-	r.ListAndWatch(stopCh)
+	require.NoError(t, r.ListAndWatchWithContext(ctx))
 
 	results := s.List()
 	if len(results) != 10 {
@@ -942,13 +963,14 @@ func TestReflectorNotPaginatingNotConsistentReads(t *testing.T) {
 }
 
 func TestReflectorPaginatingNonConsistentReadsIfWatchCacheDisabled(t *testing.T) {
-	var stopCh chan struct{}
+	_, ctx := ktesting.NewTestContext(t)
+	var cancel func(error)
 	s := NewStore(MetaNamespaceKeyFunc)
 
 	lw := &testLW{
 		WatchFunc: func(options metav1.ListOptions) (watch.Interface, error) {
 			// Stop once the reflector begins watching since we're only interested in the list.
-			close(stopCh)
+			cancel(errors.New("done"))
 			fw := watch.NewFake()
 			return fw, nil
 		},
@@ -977,16 +999,17 @@ func TestReflectorPaginatingNonConsistentReadsIfWatchCacheDisabled(t *testing.T)
 	r := NewReflector(lw, &v1.Pod{}, s, 0)
 
 	// Initial list should initialize paginatedResult in the reflector.
-	stopCh = make(chan struct{})
+	var cancelCtx context.Context
-	r.ListAndWatch(stopCh)
+	cancelCtx, cancel = context.WithCancelCause(ctx)
+	require.NoError(t, r.ListAndWatchWithContext(cancelCtx))
 	if results := s.List(); len(results) != 10 {
 		t.Errorf("Expected 10 results, got %d", len(results))
 	}
 
 	// Since initial list for ResourceVersion="0" was paginated, the subsequent
 	// ones should also be paginated.
-	stopCh = make(chan struct{})
+	cancelCtx, cancel = context.WithCancelCause(ctx)
-	r.ListAndWatch(stopCh)
+	require.NoError(t, r.ListAndWatchWithContext(cancelCtx))
 	if results := s.List(); len(results) != 10 {
 		t.Errorf("Expected 10 results, got %d", len(results))
 	}
@@ -996,14 +1019,15 @@ func TestReflectorPaginatingNonConsistentReadsIfWatchCacheDisabled(t *testing.T)
 // it in relist requests to prevent the reflector from traveling back in time if the relist is to a api-server or
 // etcd that is partitioned and serving older data than the reflector has already processed.
 func TestReflectorResyncWithResourceVersion(t *testing.T) {
-	stopCh := make(chan struct{})
+	_, ctx := ktesting.NewTestContext(t)
+	cancelCtx, cancel := context.WithCancelCause(ctx)
 	s := NewStore(MetaNamespaceKeyFunc)
 	listCallRVs := []string{}
 
 	lw := &testLW{
 		WatchFunc: func(options metav1.ListOptions) (watch.Interface, error) {
 			// Stop once the reflector begins watching since we're only interested in the list.
-			close(stopCh)
+			cancel(errors.New("done"))
 			fw := watch.NewFake()
 			return fw, nil
 		},
@@ -1027,7 +1051,7 @@ func TestReflectorResyncWithResourceVersion(t *testing.T) {
 	r := NewReflector(lw, &v1.Pod{}, s, 0)
 
 	// Initial list should use RV=0
-	r.ListAndWatch(stopCh)
+	require.NoError(t, r.ListAndWatchWithContext(cancelCtx))
 
 	results := s.List()
 	if len(results) != 4 {
@@ -1035,8 +1059,8 @@ func TestReflectorResyncWithResourceVersion(t *testing.T) {
 	}
 
 	// relist should use lastSyncResourceVersions (RV=10)
-	stopCh = make(chan struct{})
+	cancelCtx, cancel = context.WithCancelCause(ctx)
-	r.ListAndWatch(stopCh)
+	require.NoError(t, r.ListAndWatchWithContext(cancelCtx))
 
 	results = s.List()
 	if len(results) != 8 {
@@ -1055,14 +1079,16 @@ func TestReflectorResyncWithResourceVersion(t *testing.T) {
 // (In kubernetes 1.17, or when the watch cache is enabled, the List will instead return the list that is no older than
 // the requested ResourceVersion).
 func TestReflectorExpiredExactResourceVersion(t *testing.T) {
-	stopCh := make(chan struct{})
+	_, ctx := ktesting.NewTestContext(t)
+	var cancelCtx context.Context
+	var cancel func(error)
 	s := NewStore(MetaNamespaceKeyFunc)
 	listCallRVs := []string{}
 
 	lw := &testLW{
 		WatchFunc: func(options metav1.ListOptions) (watch.Interface, error) {
 			// Stop once the reflector begins watching since we're only interested in the list.
-			close(stopCh)
+			cancel(errors.New("done"))
 			fw := watch.NewFake()
 			return fw, nil
 		},
@@ -1089,7 +1115,8 @@ func TestReflectorExpiredExactResourceVersion(t *testing.T) {
 	r := NewReflector(lw, &v1.Pod{}, s, 0)
 
 	// Initial list should use RV=0
-	r.ListAndWatch(stopCh)
+	cancelCtx, cancel = context.WithCancelCause(ctx)
+	require.NoError(t, r.ListAndWatchWithContext(cancelCtx))
 
 	results := s.List()
 	if len(results) != 4 {
@@ -1097,8 +1124,8 @@ func TestReflectorExpiredExactResourceVersion(t *testing.T) {
 	}
 
 	// relist should use lastSyncResourceVersions (RV=10) and since RV=10 is expired, it should retry with RV="".
-	stopCh = make(chan struct{})
+	cancelCtx, cancel = context.WithCancelCause(ctx)
-	r.ListAndWatch(stopCh)
+	require.NoError(t, r.ListAndWatchWithContext(cancelCtx))
 
 	results = s.List()
 	if len(results) != 8 {
@@ -1112,14 +1139,16 @@ func TestReflectorExpiredExactResourceVersion(t *testing.T) {
 }
 
 func TestReflectorFullListIfExpired(t *testing.T) {
-	stopCh := make(chan struct{})
+	_, ctx := ktesting.NewTestContext(t)
+	var cancelCtx context.Context
+	var cancel func(error)
 	s := NewStore(MetaNamespaceKeyFunc)
 	listCallRVs := []string{}
 
 	lw := &testLW{
 		WatchFunc: func(options metav1.ListOptions) (watch.Interface, error) {
 			// Stop once the reflector begins watching since we're only interested in the list.
-			close(stopCh)
+			cancel(errors.New("done"))
 			fw := watch.NewFake()
 			return fw, nil
 		},
@@ -1156,7 +1185,8 @@ func TestReflectorFullListIfExpired(t *testing.T) {
 	r.WatchListPageSize = 4
 
 	// Initial list should use RV=0
-	if err := r.ListAndWatch(stopCh); err != nil {
+	cancelCtx, cancel = context.WithCancelCause(ctx)
+	if err := r.ListAndWatchWithContext(cancelCtx); err != nil {
 		t.Fatal(err)
 	}
 
@@ -1166,8 +1196,8 @@ func TestReflectorFullListIfExpired(t *testing.T) {
 	}
 
 	// relist should use lastSyncResourceVersions (RV=10) and since second page of that expired, it should full list with RV=10
-	stopCh = make(chan struct{})
+	cancelCtx, cancel = context.WithCancelCause(ctx)
-	if err := r.ListAndWatch(stopCh); err != nil {
+	if err := r.ListAndWatchWithContext(cancelCtx); err != nil {
 		t.Fatal(err)
 	}
 
@@ -1183,7 +1213,9 @@ func TestReflectorFullListIfExpired(t *testing.T) {
 }
 
 func TestReflectorFullListIfTooLarge(t *testing.T) {
-	stopCh := make(chan struct{})
+	_, ctx := ktesting.NewTestContext(t)
+	var cancelCtx context.Context
+	var cancel func(error)
 	s := NewStore(MetaNamespaceKeyFunc)
 	listCallRVs := []string{}
 	version := 30
@@ -1191,7 +1223,7 @@ func TestReflectorFullListIfTooLarge(t *testing.T) {
 	lw := &testLW{
 		WatchFunc: func(options metav1.ListOptions) (watch.Interface, error) {
 			// Stop once the reflector begins watching since we're only interested in the list.
-			close(stopCh)
+			cancel(errors.New("done"))
 			fw := watch.NewFake()
 			return fw, nil
 		},
@@ -1229,7 +1261,8 @@ func TestReflectorFullListIfTooLarge(t *testing.T) {
 	r := NewReflector(lw, &v1.Pod{}, s, 0)
 
 	// Initial list should use RV=0
-	if err := r.ListAndWatch(stopCh); err != nil {
+	cancelCtx, cancel = context.WithCancelCause(ctx)
+	if err := r.ListAndWatchWithContext(cancelCtx); err != nil {
 		t.Fatal(err)
 	}
 
@@ -1241,8 +1274,8 @@ func TestReflectorFullListIfTooLarge(t *testing.T) {
 	// done we simply try to relist from now to avoid continuous errors on relists.
 	for i := 1; i <= 3; i++ {
 		// relist twice to cover the two variants of TooLargeResourceVersion api errors
-		stopCh = make(chan struct{})
+		cancelCtx, cancel = context.WithCancelCause(ctx)
-		if err := r.ListAndWatch(stopCh); err != nil {
+		if err := r.ListAndWatchWithContext(cancelCtx); err != nil {
 			t.Fatal(err)
 		}
 	}
@@ -1356,7 +1389,8 @@ func TestWatchTimeout(t *testing.T) {
 
 	for _, tc := range testCases {
 		t.Run(tc.name, func(t *testing.T) {
-			stopCh := make(chan struct{})
+			_, ctx := ktesting.NewTestContext(t)
+			ctx, cancel := context.WithCancelCause(ctx)
 			s := NewStore(MetaNamespaceKeyFunc)
 			var gotTimeoutSeconds int64
 
@@ -1370,7 +1404,7 @@ func TestWatchTimeout(t *testing.T) {
 					}
 
 					// Stop once the reflector begins watching since we're only interested in the list.
-					close(stopCh)
+					cancel(errors.New("done"))
 					return watch.NewFake(), nil
 				},
 			}
@@ -1379,7 +1413,7 @@ func TestWatchTimeout(t *testing.T) {
 				MinWatchTimeout: tc.minWatchTimeout,
 			}
 			r := NewReflectorWithOptions(lw, &v1.Pod{}, s, opts)
-			if err := r.ListAndWatch(stopCh); err != nil {
+			if err := r.ListAndWatchWithContext(ctx); err != nil {
 				t.Fatal(err)
 			}
 
@@ -1412,7 +1446,8 @@ func newStoreWithRV() *storeWithRV {
 func TestReflectorResourceVersionUpdate(t *testing.T) {
 	s := newStoreWithRV()
 
-	stopCh := make(chan struct{})
+	_, ctx := ktesting.NewTestContext(t)
+	ctx, cancel := context.WithCancelCause(ctx)
 	fw := watch.NewFake()
 
 	lw := &testLW{
@@ -1434,11 +1469,11 @@ func TestReflectorResourceVersionUpdate(t *testing.T) {
 		fw.Action(watch.Modified, makePod("20"))
 		fw.Action(watch.Bookmark, makePod("30"))
 		fw.Action(watch.Deleted, makePod("40"))
-		close(stopCh)
+		cancel(errors.New("done"))
 	}()
 
 	// Initial list should use RV=0
-	if err := r.ListAndWatch(stopCh); err != nil {
+	if err := r.ListAndWatchWithContext(ctx); err != nil {
 		t.Fatal(err)
 	}
 
@@ -1680,6 +1715,7 @@ func (t *TestPagingPodsLW) Watch(options metav1.ListOptions) (watch.Interface, e
 }
 
 func TestReflectorListExtract(t *testing.T) {
+	_, ctx := ktesting.NewTestContext(t)
 	store := NewStore(func(obj interface{}) (string, error) {
 		pod, ok := obj.(*v1.Pod)
 		if !ok {
@@ -1693,8 +1729,7 @@ func TestReflectorListExtract(t *testing.T) {
 	reflector.WatchListPageSize = fakeItemsNum
 
 	// execute list to fill store
-	stopCh := make(chan struct{})
+	if err := reflector.list(ctx); err != nil {
-	if err := reflector.list(stopCh); err != nil {
 		t.Fatal(err)
 	}
 
@@ -2074,7 +2109,7 @@ func BenchmarkReflectorList(b *testing.B) {
 
 			b.ResetTimer()
 			for i := 0; i < b.N; i++ {
-				err := reflector.list(ctx.Done())
+				err := reflector.list(ctx)
 				if err != nil {
 					b.Fatalf("reflect list: %v", err)
 				}

tools/cache/reflector_watchlist_test.go

@@ -17,6 +17,7 @@ limitations under the License.
 package cache
 
 import (
+	"context"
 	"errors"
 	"fmt"
 	"sort"
@@ -35,6 +36,7 @@ import (
 	"k8s.io/apimachinery/pkg/runtime/schema"
 	"k8s.io/apimachinery/pkg/types"
 	"k8s.io/apimachinery/pkg/watch"
+	"k8s.io/klog/v2/ktesting"
 	testingclock "k8s.io/utils/clock/testing"
 	"k8s.io/utils/pointer"
 	"k8s.io/utils/ptr"
@@ -51,8 +53,9 @@ func TestInitialEventsEndBookmarkTicker(t *testing.T) {
 	}
 
 	t.Run("testing NoopInitialEventsEndBookmarkTicker", func(t *testing.T) {
+		logger, _ := ktesting.NewTestContext(t)
 		clock := testingclock.NewFakeClock(time.Now())
-		target := newInitialEventsEndBookmarkTickerInternal("testName", clock, clock.Now(), time.Second, false)
+		target := newInitialEventsEndBookmarkTickerInternal(logger, "testName", clock, clock.Now(), time.Second, false)
 
 		clock.Step(30 * time.Second)
 		assertNoEvents(t, target.C())
@@ -73,8 +76,9 @@ func TestInitialEventsEndBookmarkTicker(t *testing.T) {
 	})
 
 	t.Run("testing InitialEventsEndBookmarkTicker backed by a fake clock", func(t *testing.T) {
+		logger, _ := ktesting.NewTestContext(t)
 		clock := testingclock.NewFakeClock(time.Now())
-		target := newInitialEventsEndBookmarkTickerInternal("testName", clock, clock.Now(), time.Second, true)
+		target := newInitialEventsEndBookmarkTickerInternal(logger, "testName", clock, clock.Now(), time.Second, true)
 		clock.Step(500 * time.Millisecond)
 		assertNoEvents(t, target.C())
 
@@ -469,7 +473,8 @@ func TestWatchList(t *testing.T) {
 	for _, s := range scenarios {
 		t.Run(s.name, func(t *testing.T) {
 			scenario := s // capture as local variable
-			listWatcher, store, reflector, stopCh := testData()
+			_, ctx := ktesting.NewTestContext(t)
+			listWatcher, store, reflector, ctx, cancel := testData(ctx)
 			go func() {
 				for i, e := range scenario.watchEvents {
 					listWatcher.fakeWatcher.Action(e.Type, e.Object)
@@ -478,7 +483,7 @@ func TestWatchList(t *testing.T) {
 						continue
 					}
 					if i+1 == scenario.closeAfterWatchEvents {
-						close(stopCh)
+						cancel(fmt.Errorf("done after %d watch events", i))
 					}
 				}
 			}()
@@ -490,7 +495,7 @@ func TestWatchList(t *testing.T) {
 				reflector.UseWatchList = ptr.To(false)
 			}
 
-			err := reflector.ListAndWatch(stopCh)
+			err := reflector.ListAndWatchWithContext(ctx)
 			if scenario.expectedError != nil && err == nil {
 				t.Fatalf("expected error %q, got nil", scenario.expectedError)
 			}
@@ -567,19 +572,19 @@ func makePod(name, rv string) *v1.Pod {
 	return &v1.Pod{ObjectMeta: metav1.ObjectMeta{Name: name, ResourceVersion: rv, UID: types.UID(name)}}
 }
 
-func testData() (*fakeListWatcher, Store, *Reflector, chan struct{}) {
+func testData(ctx context.Context) (*fakeListWatcher, Store, *Reflector, context.Context, func(error)) {
+	ctx, cancel := context.WithCancelCause(ctx)
 	s := NewStore(MetaNamespaceKeyFunc)
-	stopCh := make(chan struct{})
 	lw := &fakeListWatcher{
 		fakeWatcher: watch.NewFake(),
 		stop: func() {
-			close(stopCh)
+			cancel(errors.New("time to stop"))
 		},
 	}
 	r := NewReflector(lw, &v1.Pod{}, s, 0)
 	r.UseWatchList = ptr.To(true)
 
-	return lw, s, r, stopCh
+	return lw, s, r, ctx, cancel
 }
 
 type fakeListWatcher struct {

tools/cache/shared_informer.go

@@ -17,6 +17,7 @@ limitations under the License.
 package cache
 
 import (
+	"context"
 	"errors"
 	"fmt"
 	"sync"
@@ -29,6 +30,7 @@ import (
 	"k8s.io/client-go/tools/cache/synctrack"
 	"k8s.io/utils/buffer"
 	"k8s.io/utils/clock"
+	"k8s.io/utils/ptr"
 
 	"k8s.io/klog/v2"
 
@@ -142,6 +144,8 @@ type SharedInformer interface {
 	// It returns a registration handle for the handler that can be used to
 	// remove the handler again, or to tell if the handler is synced (has
 	// seen every item in the initial list).
+	//
+	// Contextual logging: AddEventHandlerWithOptions together with a logger in the options should be used instead of AddEventHandler in code which supports contextual logging.
 	AddEventHandler(handler ResourceEventHandler) (ResourceEventHandlerRegistration, error)
 	// AddEventHandlerWithResyncPeriod adds an event handler to the
 	// shared informer with the requested resync period; zero means
@@ -159,7 +163,12 @@ type SharedInformer interface {
 	// be competing load and scheduling noise.
 	// It returns a registration handle for the handler that can be used to remove
 	// the handler again and an error if the handler cannot be added.
+	//
+	// Contextual logging: AddEventHandlerWithOptions together with a logger in the options should be used instead of AddEventHandlerWithResyncPeriod in code which supports contextual logging.
 	AddEventHandlerWithResyncPeriod(handler ResourceEventHandler, resyncPeriod time.Duration) (ResourceEventHandlerRegistration, error)
+	// AddEventHandlerWithOptions is a variant of AddEventHandlerWithResyncPeriod where
+	// all optional parameters are passed in a struct.
+	AddEventHandlerWithOptions(handler ResourceEventHandler, options HandlerOptions) (ResourceEventHandlerRegistration, error)
 	// RemoveEventHandler removes a formerly added event handler given by
 	// its registration handle.
 	// This function is guaranteed to be idempotent, and thread-safe.
@@ -170,7 +179,12 @@ type SharedInformer interface {
 	GetController() Controller
 	// Run starts and runs the shared informer, returning after it stops.
 	// The informer will be stopped when stopCh is closed.
+	//
+	// Contextual logging: RunWithContext should be used instead of Run in code which uses contextual logging.
 	Run(stopCh <-chan struct{})
+	// RunWithContext starts and runs the shared informer, returning after it stops.
+	// The informer will be stopped when the context is canceled.
+	RunWithContext(ctx context.Context)
 	// HasSynced returns true if the shared informer's store has been
 	// informed by at least one full LIST of the authoritative state
 	// of the informer's object collection.  This is unrelated to "resync".
@@ -197,8 +211,14 @@ type SharedInformer interface {
 	// The handler is intended for visibility, not to e.g. pause the consumers.
 	// The handler should return quickly - any expensive processing should be
 	// offloaded.
+	//
+	// Contextual logging: SetWatchErrorHandlerWithContext should be used instead of SetWatchErrorHandler in code which supports contextual logging.
 	SetWatchErrorHandler(handler WatchErrorHandler) error
 
+	// SetWatchErrorHandlerWithContext is a variant of SetWatchErrorHandler where
+	// the handler is passed an additional context parameter.
+	SetWatchErrorHandlerWithContext(handler WatchErrorHandlerWithContext) error
+
 	// The TransformFunc is called for each object which is about to be stored.
 	//
 	// This function is intended for you to take the opportunity to
@@ -228,6 +248,21 @@ type ResourceEventHandlerRegistration interface {
 	HasSynced() bool
 }
 
+// Optional configuration options for [SharedInformer.AddEventHandlerWithOptions].
+// May be left empty.
+type HandlerOptions struct {
+	// Logger overrides the default klog.Background() logger.
+	Logger *klog.Logger
+
+	// ResyncPeriod requests a certain resync period from an informer. Zero
+	// means the handler does not care about resyncs. Not all informers do
+	// resyncs, even if requested. See
+	// [SharedInformer.AddEventHandlerWithResyncPeriod] for details.
+	//
+	// If nil, the default resync period of the shared informer is used.
+	ResyncPeriod *time.Duration
+}
+
 // SharedIndexInformer provides add and get Indexers ability based on SharedInformer.
 type SharedIndexInformer interface {
 	SharedInformer
@@ -309,15 +344,38 @@ const (
 // WaitForNamedCacheSync is a wrapper around WaitForCacheSync that generates log messages
 // indicating that the caller identified by name is waiting for syncs, followed by
 // either a successful or failed sync.
+//
+// Contextual logging: WaitForNamedCacheSyncWithContext should be used instead of WaitForNamedCacheSync in code which supports contextual logging.
 func WaitForNamedCacheSync(controllerName string, stopCh <-chan struct{}, cacheSyncs ...InformerSynced) bool {
-	klog.Infof("Waiting for caches to sync for %s", controllerName)
+	klog.Background().Info("Waiting for caches to sync", "controller", controllerName)
 
 	if !WaitForCacheSync(stopCh, cacheSyncs...) {
-		utilruntime.HandleError(fmt.Errorf("unable to sync caches for %s", controllerName))
+		utilruntime.HandleErrorWithContext(context.Background(), nil, "Unable to sync caches", "controller", controllerName)
 		return false
 	}
 
-	klog.Infof("Caches are synced for %s", controllerName)
+	klog.Background().Info("Caches are synced", "controller", controllerName)
+	return true
+}
+
+// WaitForNamedCacheSyncWithContext is a wrapper around WaitForCacheSyncWithContext that generates log messages
+// indicating that the caller is waiting for syncs, followed by either a successful or failed sync.
+//
+// Contextual logging can be used to identify the caller in those log messages. The log level is zero,
+// the same as in [WaitForNamedCacheSync]. If this is too verbose, then store a logger with an increased
+// threshold in the context:
+//
+//	WaitForNamedCacheSyncWithContext(klog.NewContext(ctx, logger.V(5)), ...)
+func WaitForNamedCacheSyncWithContext(ctx context.Context, cacheSyncs ...InformerSynced) bool {
+	logger := klog.FromContext(ctx)
+	logger.Info("Waiting for caches to sync")
+
+	if !WaitForCacheSync(ctx.Done(), cacheSyncs...) {
+		utilruntime.HandleErrorWithContext(ctx, nil, "Unable to sync caches")
+		return false
+	}
+
+	logger.Info("Caches are synced")
 	return true
 }
 
@@ -389,7 +447,7 @@ type sharedIndexInformer struct {
 	blockDeltas sync.Mutex
 
 	// Called whenever the ListAndWatch drops the connection with an error.
-	watchErrorHandler WatchErrorHandler
+	watchErrorHandler WatchErrorHandlerWithContext
 
 	transform TransformFunc
 }
@@ -403,6 +461,9 @@ type dummyController struct {
 	informer *sharedIndexInformer
 }
 
+func (v *dummyController) RunWithContext(context.Context) {
+}
+
 func (v *dummyController) Run(stopCh <-chan struct{}) {
 }
 
@@ -433,6 +494,12 @@ type deleteNotification struct {
 }
 
 func (s *sharedIndexInformer) SetWatchErrorHandler(handler WatchErrorHandler) error {
+	return s.SetWatchErrorHandlerWithContext(func(_ context.Context, r *Reflector, err error) {
+		handler(r, err)
+	})
+}
+
+func (s *sharedIndexInformer) SetWatchErrorHandlerWithContext(handler WatchErrorHandlerWithContext) error {
 	s.startedLock.Lock()
 	defer s.startedLock.Unlock()
 
@@ -457,10 +524,15 @@ func (s *sharedIndexInformer) SetTransform(handler TransformFunc) error {
 }
 
 func (s *sharedIndexInformer) Run(stopCh <-chan struct{}) {
-	defer utilruntime.HandleCrash()
+	s.RunWithContext(wait.ContextForChannel(stopCh))
+}
+
+func (s *sharedIndexInformer) RunWithContext(ctx context.Context) {
+	defer utilruntime.HandleCrashWithContext(ctx)
+	logger := klog.FromContext(ctx)
 
 	if s.HasStarted() {
-		klog.Warningf("The sharedIndexInformer has started, run more than once is not allowed")
+		logger.Info("Warning: the sharedIndexInformer has started, run more than once is not allowed")
 		return
 	}
 
@@ -484,7 +556,7 @@ func (s *sharedIndexInformer) Run(stopCh <-chan struct{}) {
 			ShouldResync:      s.processor.shouldResync,
 
 			Process:                      s.HandleDeltas,
-			WatchErrorHandler: s.watchErrorHandler,
+			WatchErrorHandlerWithContext: s.watchErrorHandler,
 		}
 
 		s.controller = New(cfg)
@@ -492,20 +564,24 @@ func (s *sharedIndexInformer) Run(stopCh <-chan struct{}) {
 		s.started = true
 	}()
 
-	// Separate stop channel because Processor should be stopped strictly after controller
+	// Separate stop context because Processor should be stopped strictly after controller.
-	processorStopCh := make(chan struct{})
+	// Cancelation in the parent context is ignored and all values are passed on,
+	// including - but not limited to - a logger.
+	processorStopCtx, stopProcessor := context.WithCancelCause(context.WithoutCancel(ctx))
 	var wg wait.Group
 	defer wg.Wait()                                         // Wait for Processor to stop
-	defer close(processorStopCh) // Tell Processor to stop
+	defer stopProcessor(errors.New("informer is stopping")) // Tell Processor to stop
-	wg.StartWithChannel(processorStopCh, s.cacheMutationDetector.Run)
+	// TODO: extend the MutationDetector interface so that it optionally
-	wg.StartWithChannel(processorStopCh, s.processor.run)
+	// has a RunWithContext method that we can use here.
+	wg.StartWithChannel(processorStopCtx.Done(), s.cacheMutationDetector.Run)
+	wg.StartWithContext(processorStopCtx, s.processor.run)
 
 	defer func() {
 		s.startedLock.Lock()
 		defer s.startedLock.Unlock()
 		s.stopped = true // Don't want any new listeners
 	}()
-	s.controller.Run(stopCh)
+	s.controller.RunWithContext(ctx)
 }
 
 func (s *sharedIndexInformer) HasStarted() bool {
@@ -558,19 +634,19 @@ func (s *sharedIndexInformer) GetController() Controller {
 }
 
 func (s *sharedIndexInformer) AddEventHandler(handler ResourceEventHandler) (ResourceEventHandlerRegistration, error) {
-	return s.AddEventHandlerWithResyncPeriod(handler, s.defaultEventHandlerResyncPeriod)
+	return s.AddEventHandlerWithOptions(handler, HandlerOptions{})
 }
 
-func determineResyncPeriod(desired, check time.Duration) time.Duration {
+func determineResyncPeriod(logger klog.Logger, desired, check time.Duration) time.Duration {
 	if desired == 0 {
 		return desired
 	}
 	if check == 0 {
-		klog.Warningf("The specified resyncPeriod %v is invalid because this shared informer doesn't support resyncing", desired)
+		logger.Info("Warning: the specified resyncPeriod is invalid because this shared informer doesn't support resyncing", "desired", desired)
 		return 0
 	}
 	if desired < check {
-		klog.Warningf("The specified resyncPeriod %v is being increased to the minimum resyncCheckPeriod %v", desired, check)
+		logger.Info("Warning: the specified resyncPeriod is being increased to the minimum resyncCheckPeriod", "desired", desired, "resyncCheckPeriod", check)
 		return check
 	}
 	return desired
@@ -579,6 +655,10 @@ func determineResyncPeriod(desired, check time.Duration) time.Duration {
 const minimumResyncPeriod = 1 * time.Second
 
 func (s *sharedIndexInformer) AddEventHandlerWithResyncPeriod(handler ResourceEventHandler, resyncPeriod time.Duration) (ResourceEventHandlerRegistration, error) {
+	return s.AddEventHandlerWithOptions(handler, HandlerOptions{ResyncPeriod: &resyncPeriod})
+}
+
+func (s *sharedIndexInformer) AddEventHandlerWithOptions(handler ResourceEventHandler, options HandlerOptions) (ResourceEventHandlerRegistration, error) {
 	s.startedLock.Lock()
 	defer s.startedLock.Unlock()
 
@@ -586,27 +666,30 @@ func (s *sharedIndexInformer) AddEventHandlerWithResyncPeriod(handler ResourceEv
 		return nil, fmt.Errorf("handler %v was not added to shared informer because it has stopped already", handler)
 	}
 
+	logger := ptr.Deref(options.Logger, klog.Background())
+	resyncPeriod := ptr.Deref(options.ResyncPeriod, s.defaultEventHandlerResyncPeriod)
 	if resyncPeriod > 0 {
 		if resyncPeriod < minimumResyncPeriod {
-			klog.Warningf("resyncPeriod %v is too small. Changing it to the minimum allowed value of %v", resyncPeriod, minimumResyncPeriod)
+			logger.Info("Warning: resync period is too small. Changing it to the minimum allowed value", "resyncPeriod", resyncPeriod, "minimumResyncPeriod", minimumResyncPeriod)
 			resyncPeriod = minimumResyncPeriod
 		}
 
 		if resyncPeriod < s.resyncCheckPeriod {
 			if s.started {
-				klog.Warningf("resyncPeriod %v is smaller than resyncCheckPeriod %v and the informer has already started. Changing it to %v", resyncPeriod, s.resyncCheckPeriod, s.resyncCheckPeriod)
+				logger.Info("Warning: resync period is smaller than resync check period and the informer has already started. Changing it to the resync check period", "resyncPeriod", resyncPeriod, "resyncCheckPeriod", s.resyncCheckPeriod)
+
 				resyncPeriod = s.resyncCheckPeriod
 			} else {
 				// if the event handler's resyncPeriod is smaller than the current resyncCheckPeriod, update
 				// resyncCheckPeriod to match resyncPeriod and adjust the resync periods of all the listeners
 				// accordingly
 				s.resyncCheckPeriod = resyncPeriod
-				s.processor.resyncCheckPeriodChanged(resyncPeriod)
+				s.processor.resyncCheckPeriodChanged(logger, resyncPeriod)
 			}
 		}
 	}
 
-	listener := newProcessListener(handler, resyncPeriod, determineResyncPeriod(resyncPeriod, s.resyncCheckPeriod), s.clock.Now(), initialBufferSize, s.HasSynced)
+	listener := newProcessListener(logger, handler, resyncPeriod, determineResyncPeriod(logger, resyncPeriod, s.resyncCheckPeriod), s.clock.Now(), initialBufferSize, s.HasSynced)
 
 	if !s.started {
 		return s.processor.addListener(listener), nil
@@ -794,7 +877,7 @@ func (p *sharedProcessor) distribute(obj interface{}, sync bool) {
 	}
 }
 
-func (p *sharedProcessor) run(stopCh <-chan struct{}) {
+func (p *sharedProcessor) run(ctx context.Context) {
 	func() {
 		p.listenersLock.RLock()
 		defer p.listenersLock.RUnlock()
@@ -804,7 +887,7 @@ func (p *sharedProcessor) run(stopCh <-chan struct{}) {
 		}
 		p.listenersStarted = true
 	}()
-	<-stopCh
+	<-ctx.Done()
 
 	p.listenersLock.Lock()
 	defer p.listenersLock.Unlock()
@@ -844,13 +927,13 @@ func (p *sharedProcessor) shouldResync() bool {
 	return resyncNeeded
 }
 
-func (p *sharedProcessor) resyncCheckPeriodChanged(resyncCheckPeriod time.Duration) {
+func (p *sharedProcessor) resyncCheckPeriodChanged(logger klog.Logger, resyncCheckPeriod time.Duration) {
 	p.listenersLock.RLock()
 	defer p.listenersLock.RUnlock()
 
 	for listener := range p.listeners {
 		resyncPeriod := determineResyncPeriod(
-			listener.requestedResyncPeriod, resyncCheckPeriod)
+			logger, listener.requestedResyncPeriod, resyncCheckPeriod)
 		listener.setResyncPeriod(resyncPeriod)
 	}
 }
@@ -867,6 +950,7 @@ func (p *sharedProcessor) resyncCheckPeriodChanged(resyncCheckPeriod time.Durati
 // processorListener also keeps track of the adjusted requested resync
 // period of the listener.
 type processorListener struct {
+	logger klog.Logger
 	nextCh chan interface{}
 	addCh  chan interface{}
 
@@ -910,8 +994,9 @@ func (p *processorListener) HasSynced() bool {
 	return p.syncTracker.HasSynced()
 }
 
-func newProcessListener(handler ResourceEventHandler, requestedResyncPeriod, resyncPeriod time.Duration, now time.Time, bufferSize int, hasSynced func() bool) *processorListener {
+func newProcessListener(logger klog.Logger, handler ResourceEventHandler, requestedResyncPeriod, resyncPeriod time.Duration, now time.Time, bufferSize int, hasSynced func() bool) *processorListener {
 	ret := &processorListener{
+		logger:                logger,
 		nextCh:                make(chan interface{}),
 		addCh:                 make(chan interface{}),
 		handler:               handler,
@@ -934,7 +1019,7 @@ func (p *processorListener) add(notification interface{}) {
 }
 
 func (p *processorListener) pop() {
-	defer utilruntime.HandleCrash()
+	defer utilruntime.HandleCrashWithLogger(p.logger)
 	defer close(p.nextCh) // Tell .run() to stop
 
 	var nextCh chan<- interface{}
@@ -968,9 +1053,19 @@ func (p *processorListener) run() {
 	// we will catch it, **the offending item will be skipped!**, and after a short delay (one second)
 	// the next notification will be attempted. This is usually better than the alternative of never
 	// delivering again.
-	stopCh := make(chan struct{})
+	//
-	wait.Until(func() {
+	// This only applies if utilruntime is configured to not panic, which is not the default.
+	sleepAfterCrash := false
 	for next := range p.nextCh {
+		if sleepAfterCrash {
+			// Sleep before processing the next item.
+			time.Sleep(time.Second)
+		}
+		func() {
+			// Gets reset below, but only if we get that far.
+			sleepAfterCrash = true
+			defer utilruntime.HandleCrashWithLogger(p.logger)
+
 			switch notification := next.(type) {
 			case updateNotification:
 				p.handler.OnUpdate(notification.oldObj, notification.newObj)
@@ -982,12 +1077,11 @@ func (p *processorListener) run() {
 			case deleteNotification:
 				p.handler.OnDelete(notification.oldObj)
 			default:
-				utilruntime.HandleError(fmt.Errorf("unrecognized notification: %T", next))
+				utilruntime.HandleErrorWithLogger(p.logger, nil, "unrecognized notification", "notificationType", fmt.Sprintf("%T", next))
 			}
+			sleepAfterCrash = false
+		}()
 	}
-		// the only way to get here is if the p.nextCh is empty and closed
-		close(stopCh)
-	}, 1*time.Second, stopCh)
 }
 
 // shouldResync deterimines if the listener needs a resync. If the listener's resyncPeriod is 0,

tools/cache/shared_informer_test.go

@@ -20,6 +20,7 @@ import (
 	"context"
 	"fmt"
 	"math/rand"
+	"runtime"
 	"strconv"
 	"strings"
 	"sync"
@@ -34,8 +35,13 @@ import (
 	v1 "k8s.io/api/core/v1"
 	"k8s.io/apimachinery/pkg/api/meta"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	utilruntime "k8s.io/apimachinery/pkg/util/runtime"
 	"k8s.io/apimachinery/pkg/util/sets"
 	"k8s.io/apimachinery/pkg/util/wait"
+	fcache "k8s.io/client-go/tools/cache/testing"
+	"k8s.io/klog/v2"
+	"k8s.io/klog/v2/ktesting"
+	"k8s.io/klog/v2/textlogger"
 	testingclock "k8s.io/utils/clock/testing"
 )
 
@@ -145,10 +151,15 @@ func TestIndexer(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
-	stop := make(chan struct{})
-	defer close(stop)
 
-	go informer.Run(stop)
+	var wg wait.Group
+	stop := make(chan struct{})
+	wg.StartWithChannel(stop, informer.Run)
+	defer func() {
+		close(stop)
+		wg.Wait()
+	}()
+
 	WaitForCacheSync(stop, informer.HasSynced)
 
 	cmpOps := cmpopts.SortSlices(func(a, b any) bool {
@@ -222,10 +233,13 @@ func TestListenerResyncPeriods(t *testing.T) {
 	informer.AddEventHandlerWithResyncPeriod(listener3, listener3.resyncPeriod)
 	listeners := []*testListener{listener1, listener2, listener3}
 
+	var wg wait.Group
 	stop := make(chan struct{})
-	defer close(stop)
+	wg.StartWithChannel(stop, informer.Run)
-
+	defer func() {
-	go informer.Run(stop)
+		close(stop)
+		wg.Wait()
+	}()
 
 	// ensure all listeners got the initial List
 	for _, listener := range listeners {
@@ -361,10 +375,14 @@ func TestSharedInformerInitializationRace(t *testing.T) {
 	informer := NewSharedInformer(source, &v1.Pod{}, 1*time.Second).(*sharedIndexInformer)
 	listener := newTestListener("raceListener", 0)
 
-	stop := make(chan struct{})
 	go informer.AddEventHandlerWithResyncPeriod(listener, listener.resyncPeriod)
-	go informer.Run(stop)
+	var wg wait.Group
+	stop := make(chan struct{})
+	wg.StartWithChannel(stop, informer.Run)
+	defer func() {
 		close(stop)
+		wg.Wait()
+	}()
 }
 
 // TestSharedInformerWatchDisruption simulates a watch that was closed
@@ -392,10 +410,13 @@ func TestSharedInformerWatchDisruption(t *testing.T) {
 	informer.AddEventHandlerWithResyncPeriod(listenerResync, listenerResync.resyncPeriod)
 	listeners := []*testListener{listenerNoResync, listenerResync}
 
+	var wg wait.Group
 	stop := make(chan struct{})
-	defer close(stop)
+	wg.StartWithChannel(stop, informer.Run)
-
+	defer func() {
-	go informer.Run(stop)
+		close(stop)
+		wg.Wait()
+	}()
 
 	for _, listener := range listeners {
 		if !listener.ok() {
@@ -458,8 +479,13 @@ func TestSharedInformerErrorHandling(t *testing.T) {
 		errCh <- err
 	})
 
+	var wg wait.Group
 	stop := make(chan struct{})
-	go informer.Run(stop)
+	wg.StartWithChannel(stop, informer.Run)
+	defer func() {
+		close(stop)
+		wg.Wait()
+	}()
 
 	select {
 	case err := <-errCh:
@@ -469,7 +495,6 @@ func TestSharedInformerErrorHandling(t *testing.T) {
 	case <-time.After(time.Second):
 		t.Errorf("Timeout waiting for error handler call")
 	}
-	close(stop)
 }
 
 // TestSharedInformerStartRace is a regression test to ensure there is no race between
@@ -494,9 +519,12 @@ func TestSharedInformerStartRace(t *testing.T) {
 		}
 	}()
 
-	go informer.Run(stop)
+	var wg wait.Group
-
+	wg.StartWithChannel(stop, informer.Run)
+	defer func() {
 		close(stop)
+		wg.Wait()
+	}()
 }
 
 func TestSharedInformerTransformer(t *testing.T) {
@@ -522,9 +550,13 @@ func TestSharedInformerTransformer(t *testing.T) {
 	listenerTransformer := newTestListener("listenerTransformer", 0, "POD1", "POD2")
 	informer.AddEventHandler(listenerTransformer)
 
+	var wg wait.Group
 	stop := make(chan struct{})
-	go informer.Run(stop)
+	wg.StartWithChannel(stop, informer.Run)
-	defer close(stop)
+	defer func() {
+		close(stop)
+		wg.Wait()
+	}()
 
 	if !listenerTransformer.ok() {
 		t.Errorf("%s: expected %v, got %v", listenerTransformer.name, listenerTransformer.expectedItemNames, listenerTransformer.receivedItemNames)
@@ -757,9 +789,11 @@ func TestSharedInformerHandlerAbuse(t *testing.T) {
 
 	ctx, cancel := context.WithCancel(context.Background())
 	informerCtx, informerCancel := context.WithCancel(context.Background())
-	go func() {
+	var informerWg wait.Group
-		informer.Run(informerCtx.Done())
+	informerWg.StartWithChannel(informerCtx.Done(), informer.Run)
+	defer func() {
 		cancel()
+		informerWg.Wait()
 	}()
 
 	worker := func() {
@@ -881,8 +915,10 @@ func TestStateSharedInformer(t *testing.T) {
 		t.Errorf("informer already stopped after creation")
 		return
 	}
+	var wg wait.Group
 	stop := make(chan struct{})
-	go informer.Run(stop)
+	wg.StartWithChannel(stop, informer.Run)
+	defer wg.Wait()
 	if !listener.ok() {
 		t.Errorf("informer did not report initial objects")
 		close(stop)
@@ -921,7 +957,9 @@ func TestAddOnStoppedSharedInformer(t *testing.T) {
 	informer := NewSharedInformer(source, &v1.Pod{}, 1*time.Second).(*sharedIndexInformer)
 	listener := newTestListener("listener", 0, "pod1")
 	stop := make(chan struct{})
-	go informer.Run(stop)
+	var wg wait.Group
+	wg.StartWithChannel(stop, informer.Run)
+	defer wg.Wait()
 	close(stop)
 
 	err := wait.PollImmediate(100*time.Millisecond, 2*time.Second, func() (bool, error) {
@@ -959,7 +997,9 @@ func TestRemoveOnStoppedSharedInformer(t *testing.T) {
 		return
 	}
 	stop := make(chan struct{})
-	go informer.Run(stop)
+	var wg wait.Group
+	wg.StartWithChannel(stop, informer.Run)
+	defer wg.Wait()
 	close(stop)
 	fmt.Println("sleeping")
 	time.Sleep(1 * time.Second)
@@ -986,9 +1026,13 @@ func TestRemoveWhileActive(t *testing.T) {
 	handle, _ := informer.AddEventHandler(listener)
 
 	stop := make(chan struct{})
-	defer close(stop)
+	var wg wait.Group
+	wg.StartWithChannel(stop, informer.Run)
+	defer func() {
+		close(stop)
+		wg.Wait()
+	}()
 
-	go informer.Run(stop)
 	source.Add(&v1.Pod{ObjectMeta: metav1.ObjectMeta{Name: "pod1"}})
 
 	if !listener.ok() {
@@ -1026,7 +1070,12 @@ func TestAddWhileActive(t *testing.T) {
 	}
 
 	stop := make(chan struct{})
-	defer close(stop)
+	var wg wait.Group
+	wg.StartWithChannel(stop, informer.Run)
+	defer func() {
+		close(stop)
+		wg.Wait()
+	}()
 
 	go informer.Run(stop)
 	source.Add(&v1.Pod{ObjectMeta: metav1.ObjectMeta{Name: "pod1"}})
@@ -1079,8 +1128,6 @@ func TestAddWhileActive(t *testing.T) {
 func TestShutdown(t *testing.T) {
 	t.Run("no-context", func(t *testing.T) {
 		source := newFakeControllerSource(t)
-		stop := make(chan struct{})
-		defer close(stop)
 
 		informer := NewSharedInformer(source, &v1.Pod{}, 1*time.Second)
 		handler, err := informer.AddEventHandler(ResourceEventHandlerFuncs{
@@ -1090,17 +1137,30 @@ func TestShutdown(t *testing.T) {
 		defer func() {
 			assert.NoError(t, informer.RemoveEventHandler(handler))
 		}()
-		go informer.Run(stop)
+
+		var wg wait.Group
+		stop := make(chan struct{})
+		wg.StartWithChannel(stop, informer.Run)
+		defer func() {
+			close(stop)
+			wg.Wait()
+		}()
+
 		require.Eventually(t, informer.HasSynced, time.Minute, time.Millisecond, "informer has synced")
 	})
 
 	t.Run("no-context-later", func(t *testing.T) {
 		source := newFakeControllerSource(t)
-		stop := make(chan struct{})
-		defer close(stop)
-
 		informer := NewSharedInformer(source, &v1.Pod{}, 1*time.Second)
-		go informer.Run(stop)
+
+		var wg wait.Group
+		stop := make(chan struct{})
+		wg.StartWithChannel(stop, informer.Run)
+		defer func() {
+			close(stop)
+			wg.Wait()
+		}()
+
 		require.Eventually(t, informer.HasSynced, time.Minute, time.Millisecond, "informer has synced")
 
 		handler, err := informer.AddEventHandler(ResourceEventHandlerFuncs{
@@ -1122,3 +1182,152 @@ func TestShutdown(t *testing.T) {
 		// and it doesn't matter that nothing gets stopped or removed.
 	})
 }
+
+func TestEventPanics(t *testing.T) {
+	// timeInUTC := time.Date(2009, 12, 1, 13, 30, 40, 42000, time.UTC)
+	// timeString := "1201 13:30:40.000042"
+	// Initialized by init.
+	var (
+		buffer threadSafeBuffer
+		logger klog.Logger
+		source *fcache.FakeControllerSource
+	)
+
+	init := func(t *testing.T) {
+		// Restoring state is very sensitive to ordering. All goroutines spawned
+		// by a test must have completed and there has to be a check that they
+		// have completed that is visible to the race detector. This also
+		// applies to all other tests!
+		t.Cleanup(klog.CaptureState().Restore) //nolint:logcheck // CaptureState shouldn't be used in packages with contextual logging, but here it is okay.
+		buffer.buffer.Reset()
+		logger = textlogger.NewLogger(textlogger.NewConfig(
+			// textlogger.FixedTime(timeInUTC),
+			textlogger.Output(&buffer),
+		))
+		oldReallyCrash := utilruntime.ReallyCrash
+		utilruntime.ReallyCrash = false
+		t.Cleanup(func() { utilruntime.ReallyCrash = oldReallyCrash })
+
+		source = newFakeControllerSource(t)
+		source.Add(&v1.Pod{ObjectMeta: metav1.ObjectMeta{Name: "pod1"}})
+	}
+
+	newHandler := func(ctx context.Context) ResourceEventHandlerFuncs {
+		logger := klog.FromContext(ctx)
+		return ResourceEventHandlerFuncs{
+			AddFunc: func(obj any) {
+				logger.Info("Add func will panic now", "pod", klog.KObj(obj.(*v1.Pod)))
+				panic("fake panic")
+			},
+		}
+	}
+	_, _, panicLine, _ := runtime.Caller(0)
+	panicLine -= 4
+	expectedLog := func(name string) string {
+		if name == "" {
+			return fmt.Sprintf(`shared_informer_test.go:%d] "Observed a panic" panic="fake panic"`, panicLine)
+		}
+		return fmt.Sprintf(`shared_informer_test.go:%d] "Observed a panic" logger=%q panic="fake panic"`, panicLine, name)
+	}
+	handler := newHandler(context.Background())
+
+	t.Run("simple", func(t *testing.T) {
+		init(t)
+		klog.SetLogger(logger)
+		stop := make(chan struct{})
+		informer := NewSharedInformer(source, &v1.Pod{}, 1*time.Second)
+		handle, err := informer.AddEventHandler(handler)
+		require.NoError(t, err)
+		defer func() {
+			assert.NoError(t, informer.RemoveEventHandler(handle))
+		}()
+		var wg wait.Group
+		wg.StartWithChannel(stop, informer.Run)
+		defer func() {
+			close(stop)
+			assert.Eventually(t, informer.IsStopped, time.Minute, time.Millisecond, "informer has stopped")
+			wg.Wait() // For race detector...
+		}()
+		require.Eventually(t, informer.HasSynced, time.Minute, time.Millisecond, "informer has synced")
+
+		// This times out (https://github.com/kubernetes/kubernetes/issues/129024) because the
+		// handler never syncs when the callback panics:
+		//    require.Eventually(t, handle.HasSynced, time.Minute, time.Millisecond, "handler has synced")
+		//
+		// Wait for a non-empty buffer instead. This implies that we have to make
+		// the buffer thread-safe, which wouldn't be necessary otherwise.
+		assert.EventuallyWithT(t, func(t *assert.CollectT) {
+			assert.Contains(t, buffer.String(), expectedLog(""))
+		}, time.Minute, time.Millisecond, "handler has panicked")
+	})
+
+	t.Run("many", func(t *testing.T) {
+		init(t)
+		// One pod was already created in init, add some more.
+		numPods := 5
+		for i := 1; i < numPods; i++ {
+			source.Add(&v1.Pod{ObjectMeta: metav1.ObjectMeta{Name: fmt.Sprintf("pod%d", i+1)}})
+		}
+		_, ctx := ktesting.NewTestContext(t)
+		ctx, cancel := context.WithCancel(ctx)
+		defer cancel()
+
+		informer := NewSharedInformer(source, &v1.Pod{}, 1*time.Second)
+		name1 := "fake-event-handler-1"
+		logger1 := klog.LoggerWithName(logger, name1)
+		ctx1 := klog.NewContext(ctx, logger1)
+		handle1, err := informer.AddEventHandlerWithOptions(newHandler(ctx1), HandlerOptions{Logger: &logger1})
+		require.NoError(t, err)
+		defer func() {
+			assert.NoError(t, informer.RemoveEventHandler(handle1))
+		}()
+		name2 := "fake-event-handler-2"
+		logger2 := klog.LoggerWithName(logger, name2)
+		ctx2 := klog.NewContext(ctx, logger2)
+		handle2, err := informer.AddEventHandlerWithOptions(newHandler(ctx2), HandlerOptions{Logger: &logger2})
+		require.NoError(t, err)
+		defer func() {
+			assert.NoError(t, informer.RemoveEventHandler(handle2))
+		}()
+
+		start := time.Now()
+		var wg wait.Group
+		informerName := "informer"
+		informerLogger := klog.LoggerWithName(logger, informerName)
+		informerCtx := klog.NewContext(ctx, informerLogger)
+		wg.StartWithContext(informerCtx, informer.RunWithContext)
+		defer func() {
+			cancel()
+			assert.Eventually(t, informer.IsStopped, time.Minute, time.Millisecond, "informer has stopped")
+			wg.Wait() // For race detector...
+		}()
+		require.Eventually(t, informer.HasSynced, time.Minute, time.Millisecond, "informer has synced")
+
+		assert.EventuallyWithT(t, func(t *assert.CollectT) {
+			output := buffer.String()
+			expected := expectedLog(name1)
+			if !assert.Equal(t, numPods, numOccurrences(output, expected), "Log output should have the right number of panics for %q (search string: %q), got instead:\n%s", name1, expected, output) {
+				return
+			}
+			expected = expectedLog(name2)
+			assert.Equal(t, numPods, numOccurrences(output, expected), "Log output should have the right number of panics for %q (search string %q, got instead:\n%s", name2, expected, output)
+		}, 30*time.Second, time.Millisecond, "handler has panicked")
+
+		// Both handlers should have slept for one second after each panic,
+		// except after the last pod event because then the input channel
+		// gets closed.
+		assert.GreaterOrEqual(t, time.Since(start), time.Duration(numPods-1)*time.Second, "Delay in processorListener.run")
+	})
+}
+
+func numOccurrences(hay, needle string) int {
+	count := 0
+	for {
+		index := strings.Index(hay, needle)
+		if index < 0 {
+			return count
+		}
+		count++
+		hay = hay[index+len(needle):]
+	}
+}

tools/cache/util_test.go

@@ -17,6 +17,8 @@ limitations under the License.
 package cache
 
 import (
+	"bytes"
+	"sync"
 	"testing"
 
 	fcache "k8s.io/client-go/tools/cache/testing"
@@ -27,3 +29,21 @@ func newFakeControllerSource(tb testing.TB) *fcache.FakeControllerSource {
 	tb.Cleanup(source.Shutdown)
 	return source
 }
+
+// threadSafeBuffer is a thread-safe wrapper around bytes.Buffer.
+type threadSafeBuffer struct {
+	buffer bytes.Buffer
+	mu     sync.Mutex
+}
+
+func (b *threadSafeBuffer) Write(p []byte) (n int, err error) {
+	b.mu.Lock()
+	defer b.mu.Unlock()
+	return b.buffer.Write(p)
+}
+
+func (b *threadSafeBuffer) String() string {
+	b.mu.Lock()
+	defer b.mu.Unlock()
+	return b.buffer.String()
+}