opening.Add(tryOpen)

	setHookOpenErr(func() error {
		// Wait for all connections to enqueue.
		opening.Wait()
		return errOffline
	})

	for i := 0; i < tryOpen; i++ {
		go func() {
			opening.Done() // signal one connection is in flight
			_, err := db.Exec("will never run")
			errs <- err
		}()
	}

	opening.Wait() // wait for all workers to begin running

func (db *DB) Stats() DBStats {
	wait := db.waitDuration.Load()

	db.mu.Lock()
	defer db.mu.Unlock()

	stats := DBStats{
		MaxOpenConnections: db.maxOpen,

		Idle:            len(db.freeConn),
		OpenConnections: db.numOpen,
		InUse:           db.numOpen - len(db.freeConn),

		WaitCount:         db.waitCount,
		WaitDuration:      time.Duration(wait),
		MaxIdleClosed:     db.maxIdleClosed,

narrow, to be sure; but I THINK I can kick a little!'

  She drew her foot as far down the chimney as she could, and
waited till she heard a little animal (she couldn't guess of what
sort it was) scratching and scrambling about in the chimney close
above her:  then, saying to herself `This is Bill,' she gave one
sharp kick, and waited to see what would happen next.

  The first thing she heard was a general chorus of `There goes

narrow, to be sure; but I THINK I can kick a little!'

  She drew her foot as far down the chimney as she could, and
waited till she heard a little animal (she couldn't guess of what
sort it was) scratching and scrambling about in the chimney close
above her:  then, saying to herself `This is Bill,' she gave one
sharp kick, and waited to see what would happen next.

  The first thing she heard was a general chorus of `There goes

    }
  }

  /** A reference to a value. */
  interface ValueReference<K, V> {
    /** Returns the value. Does not block or throw exceptions. */
    @CheckForNull
    V get();

    /**
     * Waits for a value that may still be loading. Unlike get(), this method can block (in the case
     * of FutureValueReference).
     *
     * @throws ExecutionException if the loading thread throws an exception

    }
  }

  /** A reference to a value. */
  interface ValueReference<K, V> {
    /** Returns the value. Does not block or throw exceptions. */
    @CheckForNull
    V get();

    /**
     * Waits for a value that may still be loading. Unlike get(), this method can block (in the case
     * of FutureValueReference).
     *
     * @throws ExecutionException if the loading thread throws an exception

        def cleaningBarrier = blockingHttpServer.expectAndBlock("cleaning")
        def cleaningBuild = executer.withTasks("waitForCleaningBarrier").withArgument("--no-daemon").start()

        then: 'cleaning build starts and waits on its barrier'
        cleaningBarrier.waitForAllPendingCalls()

        when: 'transforming build is started'
        def transformBarrier = blockingHttpServer.expectAndBlock("transform")

    ExecutorService executor = newSingleThreadExecutor();
    Future<V> waiter =
        executor.submit(
            new Callable<V>() {
              @Override
              public V call() throws Exception {
                return input.get();
              }
            });

    try {
      return getUninterruptibly(waiter, timeout, unit);
    } catch (ExecutionException e) {

    ExecutorService executor = newSingleThreadExecutor();
    Future<V> waiter =
        executor.submit(
            new Callable<V>() {
              @Override
              public V call() throws Exception {
                return input.get();
              }
            });

    try {
      return getUninterruptibly(waiter, timeout, unit);
    } catch (ExecutionException e) {

* Cherrypick [#34851](https://github.com/kubernetes/kubernetes/pull/34851) "Only wait for cache syncs once in NodeController" ([#34861](https://github.com/kubernetes/kubernetes/pull/34861), [@jessfraz](https://github.com/jessfraz))
* NodeController waits for informer sync before doing anything ([#34809](https://github.com/kubernetes/kubernetes/pull/34809), [@gmarek](https://github.com/gmarek))