WACK test fails with an error saying the Trim method was not called

Question

Hi all,

 I am working on D3D + XAML application for Winodws 8.1 and I am trying to get an all clear on the WACK test. Everything goes fine but one test "Direct3D Feature Test". The error message is: "One or more applications in the package did not call Trim() on their DXGI Devices while being suspended."

I believe I am calling the Trim method properly. I was following a sample application code. This sample application is available with the name "DirectX 3D shooting game sample" in the "Windows 8.1 app samples" available on MSDN.

Below is a little code snippet.

void App::OnLaunched(LaunchActivatedEventArgs^ args)
{
    Suspending += ref new SuspendingEventHandler(this, &App::OnSuspending);
    Resuming += ref new EventHandler<Object^>(this, &App::OnResuming);

.....

}


void App::OnSuspending(Object^ sender, SuspendingEventArgs^ args)
{

	SuspendingDeferral^ deferral = args->SuspendingOperation->GetDeferral();

	create_task([this, deferral]()
	{
		m_deviceResources->Trim();

		deferral->Complete();
	});
}

//And inside the DeviceResources implementation
void DX::DeviceResources::Trim()
{
	ComPtr<IDXGIDevice3> dxgiDevice;
	DX::ThrowIfFailed(m_d3dDevice.As(&dxgiDevice));

	dxgiDevice->Trim();
}

//declaration of m_d3dDevice
Microsoft::WRL::ComPtr<ID3D11Device2> m_d3dDevice;

Can someone please guide to what I might be missing? Perhaps, some additional suspend event handler registration or a different implementation/way of calling Trim() ?

Answer 1

void SimpleSample::OnSuspending(Platform::Object^ sender, SuspendingEventArgs^ args)
{
	// Save app state asynchronously after requesting a deferral. Holding a deferral
	// indicates that the application is busy performing suspending operations. Be
	// aware that a deferral may not be held indefinitely. After about five seconds,
	// the app will be forced to exit.
	SuspendingDeferral^ deferral = args->SuspendingOperation->GetDeferral();

	create_task([this, deferral]()
	{
		Direct3DBase::Trimmer();
		deferral->Complete();
	});
}

//////////////////////////////////////////////////////


		void Direct3DBase::Trimmer()
		{

			IDXGIDevice3 * pDXGIDevice;
			HRESULT hr = pDXGIDevice->QueryInterface(__uuidof(dxgiDevice), (void **) &pDXGIDevice);
			pDXGIDevice->Trim();

		}

---

n.Wright

Answer 2

The code for the Trimmer method will cause a crash because of using QueryInterface from a null object. I looked at a online document and accordingly made the following changes:

IDXGIDevice3 * pDXGIDevice;
HRESULT hr = m_d3dDevice->QueryInterface(__uuidof(IDXGIDevice3), (void **) &pDXGIDevice);
pDXGIDevice->Trim();

After this, I get the same error saying Trim was not called.