// 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.`,

	"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.

	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

				makePVC("pvc-a", waitSC.Name).withBoundPV("pv-a").PersistentVolumeClaim,
				makePVC("pvc-b", waitSC.Name).withBoundPV("pv-b").PersistentVolumeClaim,
			},
			pvs: []*v1.PersistentVolume{
				makePV("pv-a", waitSC.Name).withPhase(v1.VolumeBound).withNodeAffinity(map[string][]string{
					v1.LabelHostname: {"node-a"},
				}).PersistentVolume,

	cmd.Env = append(os.Environ(), fmt.Sprintf("%s=%s", dirVar, dir))

	qDone := make(chan struct{})
	waitQ := mustBlock(t, "Edit A and B in subprocess", func() {
		out, err := cmd.CombinedOutput()
		if err != nil {
			t.Errorf("%v:\n%s", err, out)
		}
		close(qDone)
	})

	// Wait until process Q has either failed or locked file B.
	// Otherwise, P.2 might not block on file B as intended.
locked:
	for {

		t.Fatalf("failed to start KMS plugin: err: %v", err)
	}
	return result
}

// waitForBase64PluginToBeUp waits until the plugin is ready to serve requests.
func waitForBase64PluginToBeUp(plugin *Base64Plugin) error {
	var gRPCErr error
	var resp *kmsapi.StatusResponse
	pollErr := wait.PollImmediate(1*time.Second, wait.ForeverTestTimeout, func() (bool, error) {
		resp, gRPCErr = plugin.Status(context.Background(), &kmsapi.StatusRequest{})

    try {
      return satisfied = guard.isSatisfied();
    } finally {
      if (!satisfied) {
        lock.unlock();
      }
    }
  }

  /**
   * Waits for the guard to be satisfied. Waits indefinitely, but may be interrupted. May be called
   * only by a thread currently occupying this monitor.
   *
   * @throws InterruptedException if interrupted while waiting
   */