> ## Documentation Index
> Fetch the complete documentation index at: https://devdocs.xbox.com/llms.txt
> Use this file to discover all available pages before exploring further.

# XTaskQueueRegisterMonitor

> XTaskQueueRegisterMonitor

# XTaskQueueRegisterMonitor

注册一个回调，每当有回调提交到此队列时都会调用该回调。

## Syntax

```cpp theme={null}
HRESULT XTaskQueueRegisterMonitor(  
         XTaskQueueHandle queue,  
         void* callbackContext,  
         XTaskQueueMonitorCallback* callback,  
         XTaskQueueRegistrationToken* token  
)  
```

### Parameters

*queue*   \_In\_\
类型：XTaskQueueHandle

要向其注册提交回调的队列。

*callbackContext*   \_In\_opt\_\
类型：void\*

要传递给提交回调的可选上下文指针。

*callback*   \_In\_\
类型：[XTaskQueueMonitorCallback\*](/reference/system/xtaskqueue/functions/xtaskqueuemonitorcallback)

当新回调提交到队列时将调用的回调。

*token*   \_Out\_\
类型：[XTaskQueueRegistrationToken\*](/reference/system/xtaskqueue/structs/xtaskqueueregistrationtoken)

调用 [XTaskQueueUnregisterMonitor](/reference/system/xtaskqueue/functions/xtaskqueueunregistermonitor) 移除回调时使用的令牌。

### Return value

类型：HRESULT

HRESULT 成功或错误代码。

## Remarks

<Note>此函数在时间敏感线程上调用不安全。有关详细信息，请参阅[时间敏感线程](https://learn.microsoft.com/gaming/gdk/docs/gdk-dev/console-dev/overviews/threads/time-sensitive-threads)。</Note>

以下示例展示了任务队列如何在有项要调度时向条件变量发出信号。应用程序可以使用它将其用于任务队列的线程与应用程序中的其他工作共享。

<Note>**SubmitCallback** 是在 [XTaskQueueSubmitCallback](/reference/system/xtaskqueue/functions/xtaskqueuesubmitcallback) 函数的代码示例中定义的帮助程序函数。</Note>

```cpp theme={null}
// 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();
}
```

## Requirements

**头文件：** XTaskQueue.h

**库：** xgameruntime.lib

**受支持的平台：** Windows、XBOX One 系列主机和 XBOX Series 主机

## Conceptual documentation

* [XTaskQueue 库概述](/build/core-features/common/async/async-libraries/async-library-xtaskqueue)
* [时间敏感线程](https://learn.microsoft.com/gaming/gdk/docs/gdk-dev/console-dev/overviews/threads/time-sensitive-threads)

## See also

[XTaskQueue 成员](/reference/system/xtaskqueue/xtaskqueue_members)\
[异步编程模型](/build/core-features/common/async/async-programming-model)\
[异步任务队列设计](/build/core-features/common/async/async-task-queue-design)