[UWP]Wake up the modern standby machine when data receive over http,

Question

Hi All,

https://stackoverflow.com/questions/57838512/wake-up-the-modern-standby-machine-when-data-receive-over-http

I saw this example which can receive the data over the socket even when machine is in sleep (Connected modern standby). https://github.com/Microsoft/Windows-universal-samples/tree/master/Samples/SocketActivityStreamSocket

Is it possible to receive the data over the HTTP instead of TCP socket?

I am using libcurl to maintain http downchannel to the server. When server has some data for the app, it directly push to the app.

LibCurlEasy.curl_easy_setopt(Handle, CurlEasyOption.TcpKeepAlive, 1L);

            onReceiveDataCallback = OnReceiveDataCallback;
            onReceiveHeaderCallback = OnReceiveHeaderCallback;
            onReadDataCallback = OnReadDataCallback;

            LibCurlEasy.curl_easy_setopt(Handle, CurlEasyOption.WriteFunction, onReceiveDataCallback);

When machine goes to sleep, how can i transfer the ownership of http, so that i can receive the data from background thread as the app will be suspended on sleep mode.

Thanks in advance.

Answer 1

Hi,

I'm not sure about if this could be work. I checked the document, if you wants to use HTTP instead of socket and keep the network communication in the background, ControlChannelTrigger Class is a good choice for you when you create background tasks. But I'm not sure if this will work in modern standby mode, you could make a try about this. 

For more information, please refer:Network communications in the background

Best regards,

Roy

---

MSDN Community Support
Please remember to click "Mark as Answer" the responses that resolved your issue, and to click "Unmark as Answer" if not. This can be beneficial to other community members reading this thread. If you have any compliments or complaints to MSDN Support, feel free to contact [e-mail].

Answer 2

Hi Roy,

I added my app to lockScreen still this line always fails.

                channel = new ControlChannelTrigger(channelId, serverKeepAliveInterval,
                                           ControlChannelTriggerResourceType.RequestHardwareSlot);

Error 

UnauthorizedAccessException: Access is denied. (Exception from HRESULT: 0x80070005 (E_ACCESSDENIED)) ControlChannelTrigger

As I mentioned that i am using Curl APIs to revive server initiated http response, so I am planing to open the same connection when machine is about to go in sleep.

I have few more question

1. Is adding the app in lock-screen is required, if yes is there any api to directly add the app in it.

2. Can i use WNS to receive the server initiated messages (Not cloud service to send the message to WNS) 

3. I am using HTTP2 to receive server message, so which option is better to use with ControlChannelTrigger (HttpClient or IXMLHttpRequest2)

Answer 3

Hi,

Have you register the background task in your manifest?

Best regards,

Roy

---

MSDN Community Support
Please remember to click "Mark as Answer" the responses that resolved your issue, and to click "Unmark as Answer" if not. This can be beneficial to other community members reading this thread. If you have any compliments or complaints to MSDN Support, feel free to contact [e-mail].

Answer 4

I am using code behind to register it.

Inside OnLaunched

foreach (var bgTask in BackgroundTaskRegistration.AllTasks)
            {
                if (bgTask.Value.Name == taskName)
                {
                    bgTask.Value.Unregister(true);
                }
            }

            BackgroundTaskBuilder builder = new BackgroundTaskBuilder()
            {
                Name = taskName,
                TaskEntryPoint = "Mynamespace.ModernStandby.BackgroundTaskRunner"
};
uint serverKeepAliveInterval = 25;
            const string channelId = "channelOne";

            const string WebSocketKeepAliveTask = "Mynamespace.ModernStandby.WebSocketKeepAliveTask";
            ControlChannelTrigger channel =null;
            try
            {
                channel = new ControlChannelTrigger(channelId, serverKeepAliveInterval,
                                           ControlChannelTriggerResourceType.RequestHardwareSlot);
                LOG.Error("Creating is done.");
            }
            catch (UnauthorizedAccessException exp)
            {
                LOG.Error("failed "+exp);
                //return result;
            }


            // Register the apps background task with the trigger for keepalive.
            var keepAliveBuilder = new BackgroundTaskBuilder();
            keepAliveBuilder.Name = "KeepaliveTaskForChannelOne";
            keepAliveBuilder.TaskEntryPoint = WebSocketKeepAliveTask;
            //keepAliveBuilder.SetTrigger(channel.KeepAliveTrigger);
            keepAliveBuilder.Register();

            builder.SetTrigger(channel.PushNotificationTrigger);
            BackgroundTaskRegistration registration = builder.Register();
            registration.Unregister()

Answer 5

Hi,

If you wants to register a out-of-process background, you will still need to declare the background task in the manifest. If you wants to create a in-process background, then you won't need to set the TaskEntryPoint property.

For more information, please refer:Create and register an out-of-process background task and Create and register an in-process background task

Best regards,

Roy

---

MSDN Community Support
Please remember to click "Mark as Answer" the responses that resolved your issue, and to click "Unmark as Answer" if not. This can be beneficial to other community members reading this thread. If you have any compliments or complaints to MSDN Support, feel free to contact [e-mail].

Answer 6

Some how i am able to register my Background Task in my App after changing the project type to Windows runtime component 

      <Extensions>
        <Extension Category="windows.backgroundTasks" Executable="$targetnametoken$.exe" EntryPoint="NameSpace.SampleBackgroundTask">
          <BackgroundTasks>
            <Task Type="controlChannel" />
          </BackgroundTasks>
        </Extension>
        <Extension Category="windows.backgroundTasks" Executable="$targetnametoken$.exe" EntryPoint="NameSpace.ServicingComplete">
          <BackgroundTasks>
            <Task Type="controlChannel"/>
          </BackgroundTasks>
        </Extension>
      </Extensions>

So as per the doc, this will create BG task in different process, I followed this blog https://docs.microsoft.com/en-us/windows/uwp/launch-resume/debug-a-background-task#trigger-background-tasks-manually-to-debug-background-task-code to see actually my code is getting executed or not. But my break points are not getting hit. So i added a simple file write opertaion just to see my task are getting exeucted or not. It seems like Tasks are not getting  executed.

Is something else required to make run my tasks?

How can i define one of the task as KeepAlive task (I don't see an option in manifest). Since I am using ControlChannelTrigger so what should i have to do to actually run my task and keep it alive. 

WebSocketKeepAlive

I want to send hart beet to my http server whenever KeepAlive is get called, so how can i create my own class to do so.

Answer 7

Hi,

If you want to create WebSocketKeepAlive background task, please refer ControlChannelTrigger with WebSockets.

Best regards,

Roy

---

MSDN Community Support
Please remember to click "Mark as Answer" the responses that resolved your issue, and to click "Unmark as Answer" if not. This can be beneficial to other community members reading this thread. If you have any compliments or complaints to MSDN Support, feel free to contact [e-mail].

Answer 8

Hi Roy,

I register the task by using the below code.

        <Extension Category="windows.backgroundTasks" EntryPoint="BackgroundTasks.BGTask" Executable="$targetnametoken$.exe">
          <BackgroundTasks>
            <Task Type="controlChannel"/>
          </BackgroundTasks>
        </Extension>

I am facing below compiler  error

Severity Code Description Project File Line Suppression State
Error APPX0703 Manifest references file '{My exe}.exe' which is not part of the payload.

Without 

Executable="$targetnametoken$.exe"

App fails during the deployment because of ControlChannel trigger.

How can i fix this compiler error.

Answer 9

Hi,

Well, you haven't register it yet. Calling BackgroundTaskBuilder.Register() method means you register the background task. But the code in the manifest just declare the background. I created a bank app and add the same code to the manifest file. The app could run without error. Have you tried do it in a blank app?

Best regards,

Roy

---

MSDN Community Support
Please remember to click "Mark as Answer" the responses that resolved your issue, and to click "Unmark as Answer" if not. This can be beneficial to other community members reading this thread. If you have any compliments or complaints to MSDN Support, feel free to contact [e-mail].

Answer 10

Hi Roy,

Which App you are taking about? Can you please share the app?

If you see the code of https://github.com/microsoft/Windows-universal-samples/tree/master/Samples/SocketActivityStreamSocket/cs

This does not requires a Task Registration again in App.xaml.cs, Manifest registration is sufficient to  run the code. Only diff is i have in my case is that i am using ControllChannelTrigger instead of timer or systemEvent.

 

Answer 11

A blank app. A new created app. NOT the sample. As I know, the sample implemented the background network communication already. I think it's not possible to trigger this in sleep mode. Sleep mode has many limitations and most of the resources are not available. 

This https://docs.microsoft.com/en-us/windows-hardware/design/device-experiences/modern-standby-wake-sources#universal-windows-platform-uwp-applications-1 tells only notifications will work.

Answer 12

Hi Roy,

As per the MS documentation 

Regardless of the trigger you use, set IsNetworkRequested on your background task to ensure that the network stays up while the background task runs. This tells the background task infrastructure to keep the network up while the task is executing, even if the device has entered Connected Standby mode. If your background task does not use IsNetworkRequested, then your background task will not be able to access the network when in Connected Standby mode (for example, when a phone's screen is turned off)

To me it seems like BG task can work with connected modern standby, correct? 

I am struggling to make a working POC on this :(

Answer 13

I don't think it will work because network resource is not the waken resource.