https://github.com/facebook/react/blob/30b47103d4354d9187dc0f1fb804855a5208ca9f/packages/scheduler/src/Scheduler.js#L180-L185
}
  isPerformingWork = true;
  const previousPriorityLevel = currentPriorityLevel;
  try {
    if (enableProfiling) {
      try {
        return workLoop(hasTimeRemaining, initialTime);
      } catch (error) {
        if (currentTask !== null) {
          const currentTime = getCurrentTime();
          markTaskErrored(currentTask, currentTime);
          currentTask.isQueued = false;
        }
        throw error;
      }
    } else {
      
      return workLoop(hasTimeRemaining, initialTime);
    }
  } finally {
    currentTask = null;
    currentPriorityLevel = previousPriorityLevel;
    isPerformingWork = false;
    if (enableProfiling) {
      const currentTime = getCurrentTime();
      markSchedulerSuspended(currentTime);
    }
  }
}
function workLoop(hasTimeRemaining, initialTime) {