bgwork <- func() {
		defer wg.Done()
		run(dir, CheckExit|ShowOutput|Background, cmd...)
	}
}

// bgwait waits for pending bgruns to finish.
// bgwait must be called from only a single goroutine at a time.
func bgwait(wg *sync.WaitGroup) {
	done := make(chan struct{})
	go func() {
		wg.Wait()
		close(done)
	}()
	select {
	case <-done:
	case <-dying:

		link = append(link, b)
		if doclean {
			clean = append(clean, b)
		}
	}
	bgwait(&wg)

	if ispackcmd {
		xremove(link[targ])
		dopack(link[targ], archive, link[targ+1:])
		return
	}

	// Remove target before writing it.
	xremove(link[targ])
	bgrun(&wg, "", link...)
	bgwait(&wg)
}

// packagefile returns the path to a compiled .a file for the given package

	"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.

	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")

            }

            else if (type == 'progress') {
                await this.progress(line);
                await this._wait(delay);
            }

            else {
                this.container.appendChild(line);
                await this._wait(delay);
            }

            line.removeAttribute(`${this.pfx}-cursor`);
        }
        this.addRestart()

  istioctl experimental wait --for=distribution virtualservice bookinfo.default

  # Wait until the bookinfo virtual service has been distributed to a specific proxy
  istioctl experimental wait --for=distribution virtualservice bookinfo.default --proxy workload-instance.namespace

  # Wait until 99% of the proxies receive the distribution, timing out after 5 minutes

// 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.

	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

	return nil
}

// WaitForPodsWithLabel will lookup pods with the given label and wait until they are all
// reporting status as running.
func (w *KubeWaiter) WaitForPodsWithLabel(kvLabel string) error {

	lastKnownPodNumber := -1
	return wait.PollUntilContextTimeout(context.Background(),
		constants.KubernetesAPICallRetryInterval, w.timeout,

        executor.execute(wrapper);
      }
      barrier.await(); // release the threads!
      barrier.await(); // wait for them all to complete
      assertEquals(1, task.get().intValue());
      assertEquals(1, counter.get());
    }
    executor.shutdown();
  }

  @J2ktIncompatible
  @GwtIncompatible // blocking wait
  public void testToString() throws Exception {