internal var nextExecuteNanoTime = -1L

  /** Returns the delay in nanoseconds until the next execution, or -1L to not reschedule. */
  abstract fun runOnce(): Long

  internal fun initQueue(queue: TaskQueue) {
    if (this.queue === queue) return

    check(this.queue === null) { "task is in multiple queues" }
    this.queue = queue
  }

  override fun toString(): String = name

  /** Adds [task] to run in [delayNanos]. Returns true if the coordinator is impacted. */
  internal fun scheduleAndDecide(
    task: Task,
    delayNanos: Long,
    recurrence: Boolean,
  ): Boolean {
    task.initQueue(this)

    val now = taskRunner.backend.nanoTime()
    val executeNanoTime = now + delayNanos

    // If the task is already scheduled, take the earlier of the two times.