defaultExpirationSeconds = 60 * 60
)

// Audience to create tokens for
var tokenAudiences = []string{"istio-ca"}

// GetXdsResponse opens a gRPC connection to opts.xds and waits for a single response
func GetXdsResponse(dr *discovery.DiscoveryRequest, ns string, serviceAccount string, opts clioptions.CentralControlPlaneOptions,
	grpcOpts []grpc.DialOption,
) (*discovery.DiscoveryResponse, error) {

	"istio.io/istio/pkg/log"
)

type Watcher struct {
	watcher *fsnotify.Watcher
	Events  chan struct{}
	Errors  chan error
}

// Waits until a file is modified (returns nil), the context is cancelled (returns context error), or returns error
func (w *Watcher) Wait(ctx context.Context) error {
	select {
	case <-w.Events:
		return nil
	case err := <-w.Errors:
		return err
	case <-ctx.Done():
		return ctx.Err()

		// been saved at least once. The semantics here are:
		//
		// * Readers of the result will wait on the monitor until the first result
		//   has been saved.
		// * The sync loop (i.e. the only writer), will signal all waiters every
		//   time it updates the result.
		nodeAddressesMonitor: sync.NewCond(&sync.Mutex{}),
	}
}

// NodeAddresses waits for the first sync loop to run. If no successful syncs

   * necessary. No observable state associated with this cache is modified until loading completes.
   *
   * <p>If another call to {@link #get} or {@link #getUnchecked} is currently loading the value for
   * {@code key}, simply waits for that thread to finish and returns its loaded value. Note that
   * multiple threads can concurrently load values for distinct keys.
   *

func NewEtcdMigrateServer(cfg *EtcdMigrateCfg, client EtcdMigrateClient) *EtcdMigrateServer {
	return &EtcdMigrateServer{cfg: cfg, client: client}
}

// Start starts an etcd server as a separate process, waits until it has started, and returns a exec.Cmd.
// TODO: Add support for listening to client via TLS.
func (r *EtcdMigrateServer) Start(version *EtcdVersion) error {
	etcdCmd := exec.Command(

	// registration/deregistration
	AddHandler(pluginType string, pluginHandler cache.PluginHandler)
}

const (
	// loopSleepDuration is the amount of time the reconciler loop waits
	// between successive executions
	loopSleepDuration = 1 * time.Second
)

// NewPluginManager returns a new concrete instance implementing the
// PluginManager interface.
func NewPluginManager(
	sockDir string,

)

const (
	// reconcilerLoopSleepPeriod is the amount of time the reconciler loop waits
	// between successive executions
	reconcilerLoopSleepPeriod = 100 * time.Millisecond

	// desiredStateOfWorldPopulatorLoopSleepPeriod is the amount of time the
	// DesiredStateOfWorldPopulator loop waits between successive executions
	desiredStateOfWorldPopulatorLoopSleepPeriod = 100 * time.Millisecond

// handler: the sigsend function. The signal handler code does not require
// all the features of notes: it does not need to do a timed wait.
// This is a separate implementation of notes, based on a pipe, that does
// not support timed waits but is async-signal-safe.
func sigNoteSetup(*note) {
	if sigNoteRead != 0 || sigNoteWrite != 0 {

		if note != "" {
			return note
		}

		lock(&sig.lock)
		sig.sleeping = true
		noteclear(&sig.note)
		unlock(&sig.lock)
		notetsleepg(&sig.note, -1)
	}
}

// signalWaitUntilIdle waits until the signal delivery mechanism is idle.
// This is used to ensure that we do not drop a signal notification due
// to a race between disabling a signal and receiving a signal.

    slowChannel.exitClose.countDown(); // release the interrupter

    // We need to wait for the runner to exit.  To make sure that the interrupting thread wakes it
    // back up.
    runner.join(TimeUnit.SECONDS.toMillis(10));
  }

  // waits for the given thread to be blocked on the given object
  private static void awaitBlockedOnInstanceOf(Thread t, Class<?> blocker)