如何：创建手动任务队列

void CreatingTaskQueueWithManualThreads() 
{  
    // Create a manual task queue.  
    XTaskQueueHandle queue;  
  
    HRESULT hr = XTaskQueueCreate(  
        XTaskQueueDispatchMode::Manual,  
        XTaskQueueDispatchMode::Manual,  
        &queue);  
  
    if (FAILED(hr))  
    {  
        printf("Creating queue failed: 0x%x\r\n", hr);  
        return;  
    }  
  
    // We create threads to pump the queue: one thread for the work port  
    // and one thread for the completion port.  
    std::thread workThread([queue]  
    {  
        // XTaskQueueDispatch returns false when there's nothing to  
        // dispatch. Here, we wait forever for something new to come  
        // in. This will return false only if the queue is being  
        // terminated.  
        while (XTaskQueueDispatch(queue, XTaskQueuePort::Work, INFINITE));  
    });  
  
    std::thread completionThread([queue]  
    {  
        // XTaskQueueDispatch returns false when there's nothing to  
        // dispatch. Here, we wait forever for something new to come  
        // in. This will return false only if the queue is being  
        // terminated.  
        while (XTaskQueueDispatch(queue, XTaskQueuePort::Completion, INFINITE));  
    });  
  
    SubmitCallbacks(queue);  
  
    // Wait a while for the callbacks to run.  
    Sleep(1000);  
  
    // Terminating the queue will cause a waiting XTaskQueueDispatch to return  
    // false.  
    XTaskQueueTerminate(queue, true, nullptr, nullptr);  
  
    workThread.join();  
    completionThread.join();  
}