Stop channel commenting/renaming for clarity

This cleans up, adds comments, and renames things in the stop channel
fix commits for clarity.

Author: DirectXMan12

pkg/manager/internal.go

@@ -69,7 +69,7 @@ type controllerManager struct {
 	// (and EventHandlers, Sources and Predicates).
 	recorderProvider recorder.Provider
 
-	// resourceLock
+	// resourceLock forms the basis for leader election
 	resourceLock resourcelock.Interface
 
 	// mapper is used to map resources to kind, and map kind and version.
@@ -81,10 +81,16 @@ type controllerManager struct {
 	mu      sync.Mutex
 	started bool
 	errChan chan error
-	stop    <-chan struct{}
 
-	// stopper is the write side of the stop channel. They should have the same value.
-	stopper chan<- struct{}
+	// internalStop is the stop channel *actually* used by everything involved
+	// with the manager as a stop channel, so that we can pass a stop channel
+	// to things that need it off the bat (like the Channel source).  It can
+	// be closed via `internalStopper` (by being the same underlying channel).
+	internalStop <-chan struct{}
+
+	// internalStopper is the write side of the internal stop channel, allowing us to close it.
+	// It and `internalStop` should point to the same channel.
+	internalStopper chan<- struct{}
 
 	startCache func(stop <-chan struct{}) error
 }
@@ -104,7 +110,7 @@ func (cm *controllerManager) Add(r Runnable) error {
 	if cm.started {
 		// If already started, start the controller
 		go func() {
-			cm.errChan <- r.Start(cm.stop)
+			cm.errChan <- r.Start(cm.internalStop)
 		}()
 	}
 
@@ -127,7 +133,7 @@ func (cm *controllerManager) SetFields(i interface{}) error {
 	if _, err := inject.InjectorInto(cm.SetFields, i); err != nil {
 		return err
 	}
-	if _, err := inject.StopChannelInto(cm.stop, i); err != nil {
+	if _, err := inject.StopChannelInto(cm.internalStop, i); err != nil {
 		return err
 	}
 	if _, err := inject.DecoderInto(cm.admissionDecoder, i); err != nil {
@@ -195,8 +201,8 @@ func (cm *controllerManager) serveMetrics(stop <-chan struct{}) {
 }
 
 func (cm *controllerManager) Start(stop <-chan struct{}) error {
-	// join the passed-in stop channel as an upstream feeding into cm.stopper
-	defer close(cm.stopper)
+	// join the passed-in stop channel as an upstream feeding into cm.internalStopper
+	defer close(cm.internalStopper)
 
 	if cm.resourceLock != nil {
 		err := cm.startLeaderElection()
@@ -226,27 +232,27 @@ func (cm *controllerManager) start() {
 		cm.startCache = cm.cache.Start
 	}
 	go func() {
-		if err := cm.startCache(cm.stop); err != nil {
+		if err := cm.startCache(cm.internalStop); err != nil {
 			cm.errChan <- err
 		}
 	}()
 
 	// Start the metrics server
 	if cm.metricsListener != nil {
-		go cm.serveMetrics(cm.stop)
+		go cm.serveMetrics(cm.internalStop)
 	}
 
 	// Wait for the caches to sync.
 	// TODO(community): Check the return value and write a test
-	cm.cache.WaitForCacheSync(cm.stop)
+	cm.cache.WaitForCacheSync(cm.internalStop)
 
 	// Start the runnables after the cache has synced
 	for _, c := range cm.runnables {
 		// Controllers block, but we want to return an error if any have an error starting.
 		// Write any Start errors to a channel so we can return them
 		ctrl := c
 		go func() {
-			cm.errChan <- ctrl.Start(cm.stop)
+			cm.errChan <- ctrl.Start(cm.internalStop)
 		}()
 	}
 

pkg/manager/manager.go

@@ -221,8 +221,8 @@ func New(config *rest.Config, options Options) (Manager, error) {
 		resourceLock:     resourceLock,
 		mapper:           mapper,
 		metricsListener:  metricsListener,
-		stop:             stop,
-		stopper:          stop,
+		internalStop:     stop,
+		internalStopper:  stop,
 	}, nil
 }