HRESULT XTaskQueueRegisterMonitor(  
         XTaskQueueHandle queue,  
         void* callbackContext,  
         XTaskQueueMonitorCallback* callback,  
         XTaskQueueRegistrationToken* token  
)  

// We will use condition variables to signal when there is something for us 
// in the queue and a bool to signal when we want the whole thing to close.
// Keep all this in a struct for convenient access
struct QueueControl
{
    std::condition_variable workActivity;
    std::mutex workMutex;
    std::condition_variable completionActivity;
    std::mutex completionMutex;
    bool terminate = false;
} queueControl;

void CALLBACK TaskQueueNewItemSubmitted(void* context, XTaskQueueHandle, XTaskQueuePort port)
{
    // A new callback has been submitted. notify the correct condition variable
    QueueControl* queueControl = static_cast<QueueControl*>(context);
    switch (port)
    {
    case XTaskQueuePort::Work:
        queueControl->workActivity.notify_all();
        break;

    case XTaskQueuePort::Completion:
        queueControl->completionActivity.notify_all();
        break;
    }
}

void CreatingTaskQueueWithManualSignaling()
{
    // 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;
    }

    // Listen to callback submitted notifications to signal
    // our condition variable.
    XTaskQueueRegistrationToken token;
    hr = XTaskQueueRegisterMonitor(
        queue, &queueControl, 
        TaskQueueNewItemSubmitted, &token);

    std::thread workThread([&]()
    {
        std::unique_lock<std::mutex> lock(queueControl.workMutex);
        while (!queueControl.terminate)
        {
            queueControl.workActivity.wait(lock);
            XTaskQueueDispatch(queue, XTaskQueuePort::Work, 0);
        }
    });

    std::thread completionThread([&]()
    {
        std::unique_lock<std::mutex> lock(queueControl.completionMutex);
        while (!queueControl.terminate)
        {
            queueControl.completionActivity.wait(lock);
            XTaskQueueDispatch(queue, XTaskQueuePort::Completion, 0);
        }
    });

    SubmitCallbacks(queue);

    // Wait a while for the callbacks to run
    Sleep(1000);

    XTaskQueueTerminate(queue, true, nullptr, nullptr);

    queueControl.terminate = true;
    queueControl.workActivity.notify_all();
    queueControl.completionActivity.notify_all();

    workThread.join();
    completionThread.join();
}