}
    }
  }

  private fun readAndWriteFrames() {
    check(socket == null)
    val socket = serverSocket!!.accept()!!
    this.socket = socket

    // Bail out now if this instance was closed while waiting for the socket to accept.
    synchronized(this) {
      if (executor.isShutdown) {
        socket.close()
        return
      }
    }