}
    for (i in readyQueues.size - 1 downTo 0) {
      val queue = readyQueues[i]
      queue.cancelAllAndDecide()
      if (queue.futureTasks.isEmpty()) {
        readyQueues.removeAt(i)
      }
    }
  }

  interface Backend {
    fun nanoTime(): Long

    fun coordinatorNotify(taskRunner: TaskRunner)

    fun coordinatorWait(
      taskRunner: TaskRunner,

    val connection = this.connection!!
    connection.assertLockHeld()

    val calls = connection.calls
    val index = calls.indexOfFirst { it.get() == this@RealCall }
    check(index != -1)

    calls.removeAt(index)
    this.connection = null

    if (calls.isEmpty()) {
      connection.idleAtNs = System.nanoTime()
      if (connectionPool.connectionBecameIdle(connection)) {
        return connection.socket()