var firstException: IOException? = null
    try {
      while (tcpConnectsInFlight.isNotEmpty() || routePlanner.hasNext()) {
        if (routePlanner.isCanceled()) throw IOException("Canceled")

        // Launch a new connection if we're ready to.
        val now = taskRunner.backend.nanoTime()
        var awaitTimeoutNanos = nextTcpConnectAtNanos - now
        var connectResult: ConnectResult? = null

   * until one is ready. If there are no ready queues, or if other threads have everything under
   * control this will return null. If there is more than a single task ready to execute immediately
   * this will launch another thread to handle that work.
   */
  fun awaitTaskToRun(): Task? {
    lock.assertHeld()

    while (true) {
      if (readyQueues.isEmpty()) {
        return null // Nothing to do.
      }