ThreadPoolTaskScheduler.QueueTask creates a new thread for TaskCreationOptions.LongRunning

02-LongRunning-02.cs

protected internal override void QueueTask(Task task)
{
    if ((task.Options & TaskCreationOptions.LongRunning) != 0)
    {
        // Run LongRunning tasks on their own dedicated thread.
        Thread thread = new Thread(s_longRunningThreadWork);
        thread.IsBackground = true; // Keep this thread from blocking process shutdown
        thread.Start(task);
    }
    else
    {
        // Normal handling for non-LongRunning tasks.
        bool forceToGlobalQueue = ((task.Options & TaskCreationOptions.PreferFairness) != 0);
        ThreadPool.UnsafeQueueCustomWorkItem(task, forceToGlobalQueue);
    }
}