// If fork fails there is nothing to wait for.
		if ret.err != nil || ret.pid == 0 {
			forkc <- ret
			return
		}

		waitc := make(chan *waitErr, 1)

		// Mark that the process is running.
		procs.Lock()
		if procs.waits == nil {
			procs.waits = make(map[int]chan *waitErr)
		}
		procs.waits[ret.pid] = waitc
		procs.Unlock()

		forkc <- ret

		var w waitErr

	// WaitForAPI waits for the API Server's /healthz endpoint to become "ok"
	// TODO: remove WaitForAPI once WaitForAllControlPlaneComponents goes GA:
	// https://github.com/kubernetes/kubeadm/issues/2907
	WaitForAPI() error
	// WaitForPodsWithLabel waits for Pods in the kube-system namespace to become Ready
	WaitForPodsWithLabel(kvLabel string) error

const pollInterval = time.Second

// Cmd represents the wait command
func Cmd(cliCtx cli.Context) *cobra.Command {
	namespace := cliCtx.Namespace()
	var opts clioptions.ControlPlaneOptions
	cmd := &cobra.Command{
		Use:   "wait [flags] <type> <name>[.<namespace>]",
		Short: "Wait for an Istio resource",
		Long:  `Waits for the specified condition to be true of an Istio resource.`,

	waitCmd.PersistentFlags().IntVar(&timeoutSeconds, "timeoutSeconds", 60, "maximum number of seconds to wait for Envoy to be ready")
	waitCmd.PersistentFlags().IntVar(&requestTimeoutMillis, "requestTimeoutMillis", 500, "number of milliseconds to wait for response")
	waitCmd.PersistentFlags().IntVar(&periodMillis, "periodMillis", 500, "number of milliseconds to wait between attempts")

// NeverStop may be passed to Until to make it never stop.
var NeverStop <-chan struct{} = make(chan struct{})

// Group allows to start a group of goroutines and wait for their completion.
type Group struct {
	wg sync.WaitGroup
}

func (g *Group) Wait() {
	g.wg.Wait()
}

// StartWithChannel starts f in a new goroutine in the group.
// stopCh is passed to f as an argument. f should stop when stopCh is available.

	"k8s.io/apimachinery/pkg/labels"
	"k8s.io/apimachinery/pkg/util/wait"
	"k8s.io/client-go/kubernetes"
	kctldeployment "k8s.io/kubectl/pkg/util/deployment"

	"istio.io/istio/operator/pkg/name"
	"istio.io/istio/operator/pkg/object"
	"istio.io/istio/operator/pkg/util/progress"
	"istio.io/istio/pkg/kube"
)

const (
	// defaultWaitResourceTimeout is the maximum wait time for all resources(namespace/deployment/pod) to be created.

apiVersion: release-notes/v2
kind: bug-fix
area: istioctl
releaseNotes:
  - |

	if ok && r.state == Pending {
		r.state = Ready
		r.generation++
		select {
		case <-r.waitCh:
		default:
			close(r.waitCh)
		}
	} else if !ok && r.state == Ready {
		// creating the waitCh can be racy if
		// something enter the wait() method
		select {
		case <-r.waitCh:
			r.restartLock.Lock()
			r.waitCh = make(chan struct{})
			r.restartLock.Unlock()
		default:
		}
		r.state = Pending
	}

	time.Sleep(100 * time.Millisecond)

	// Write to the pipe to unblock it.
	if _, err := syscall.Write(wfd, []byte{10}); err != nil {
		log.Fatalf("failed to write to pipe: %v", err)
	}

	// Wait for the goroutine to unblock and start running.
	// This is helpful to catch incorrect information written
	// down for the syscall-blocked goroutine, since it'll start
	// executing, and that execution information will be

	// sidecar containers need to wait on main containers, so we create a channel per main container
	// for them to wait on
	for _, c := range pod.Spec.Containers {
		channel := make(chan struct{})
		to.terminated[c.Name] = channel
		mainContainerChannels = append(mainContainerChannels, channel)

		// if its not a running container, pre-close the channel so nothing waits on it