Function unstable_scheduleCallback

docs/external/js/react.development.js:2753–2822

(priorityLevel, callback, options)

  }

  function unstable_scheduleCallback(priorityLevel, callback, options) {
    var currentTime = getCurrentTime();
    var startTime;
    var timeout;

    if (typeof options === 'object' && options !== null) {
      var delay = options.delay;

      if (typeof delay === 'number' && delay > 0) {
        startTime = currentTime + delay;
      } else {
        startTime = currentTime;
      }

      timeout = typeof options.timeout === 'number' ? options.timeout : timeoutForPriorityLevel(priorityLevel);
    } else {
      timeout = timeoutForPriorityLevel(priorityLevel);
      startTime = currentTime;
    }

    var expirationTime = startTime + timeout;
    var newTask = {
      id: taskIdCounter++,
      callback: callback,
      priorityLevel: priorityLevel,
      startTime: startTime,
      expirationTime: expirationTime,
      sortIndex: -1
    };

    {
      newTask.isQueued = false;
    }

    if (startTime > currentTime) {
      // This is a delayed task.
      newTask.sortIndex = startTime;
      push(timerQueue, newTask);

      if (peek(taskQueue) === null && newTask === peek(timerQueue)) {
        // All tasks are delayed, and this is the task with the earliest delay.
        if (isHostTimeoutScheduled) {
          // Cancel an existing timeout.
          cancelHostTimeout();
        } else {
          isHostTimeoutScheduled = true;
        } // Schedule a timeout.


        requestHostTimeout(handleTimeout, startTime - currentTime);
      }
    } else {
      newTask.sortIndex = expirationTime;
      push(taskQueue, newTask);

      {
        markTaskStart(newTask, currentTime);
        newTask.isQueued = true;