Updating Texture2D frequently causes process to crash (UpdateSubresource)

Question

I am using SharpDX to basically render browser (chromium) output buffer on directX process.

Process is relatively simple, I intercept CEF buffer (by overriding OnPaint method) and write that to a texture2D.

Code is relatively simple:

Texture creation:

public void BuildTextureWrap() {
    var oldTexture = texture;

    texture = new D3D11.Texture2D(DxHandler.Device, new D3D11.Texture2DDescription() {
        Width = overlay.Size.Width,
        Height = overlay.Size.Height,
        MipLevels = 1,
        ArraySize = 1,
        Format = DXGI.Format.B8G8R8A8_UNorm,
        SampleDescription = new DXGI.SampleDescription(1, 0),
        Usage = D3D11.ResourceUsage.Default,
        BindFlags = D3D11.BindFlags.ShaderResource,
        CpuAccessFlags = D3D11.CpuAccessFlags.None,
        OptionFlags = D3D11.ResourceOptionFlags.None,
    });

    var view = new D3D11.ShaderResourceView(
        DxHandler.Device,
        texture,
        new D3D11.ShaderResourceViewDescription {
            Format = texture.Description.Format,
            Dimension = D3D.ShaderResourceViewDimension.Texture2D,
            Texture2D = { MipLevels = texture.Description.MipLevels },
        }
    );

    textureWrap = new D3DTextureWrap(view, texture.Description.Width, texture.Description.Height);

    if (oldTexture != null) {
        obsoleteTextures.Add(oldTexture);
    }
}

That piece of code is executed at start and when resize is happening.

Now when CEF OnDraw I basically copy their buffer to texture:

var destinationRegion = new D3D11.ResourceRegion {
    Top = Math.Min(r.dirtyRect.y, texDesc.Height),
    Bottom = Math.Min(r.dirtyRect.y + r.dirtyRect.height, texDesc.Height),
    Left = Math.Min(r.dirtyRect.x, texDesc.Width),
    Right = Math.Min(r.dirtyRect.x + r.dirtyRect.width, texDesc.Width),
    Front = 0,
    Back = 1,
};

// Draw to the target
var context = targetTexture.Device.ImmediateContext;
context.UpdateSubresource(targetTexture, 0, destinationRegion, sourceRegionPtr, rowPitch, depthPitch);

There are some more code out there but basically this is only relevant piece. Whole thing works until OnDraw happens frequently.

Apparently if I force CEF to Paint frequently, whole host process dies. This is happening at UpdateSubresource.

So my question is, is there another, safer way to do this? (Update texture frequently)

If it crashes, it means there's a bug in your code. What's the stack trace? Also, you can enable the DirectX debug layer https://learn.microsoft.com/en-us/windows/win32/direct3d11/using-the-debug-layer-to-test-apps https://walbourn.github.io/direct3d-sdk-debug-layer-tricks/ it usually dumps useful information if you misuse the API — Simon Mourier, Oct 21 '21 at 06:56
@SimonMourier There is no stack trace, process just dies. Unfortunately I do not have access to DirectX layer. Also there is nothing that would indicate a bug as it works for as long as i don't try to perform some animations on chrome layer (which would call OnPaint) repeatedly. That leads me to conclusion that i should map memory with different method — Kaminari, Oct 21 '21 at 07:29
You use DirectX (even through SharpDX), so you have full access to DirectX. As for the crash, when you debug your app using Visual Studio with all exceptions enabled https://learn.microsoft.com/en-us/visualstudio/debugger/managing-exceptions-with-the-debugger, you should get a stack trace. — Simon Mourier, Oct 21 '21 at 07:33
@SimonMourier Unfortunately I am a bit limited as this is being tested on linux (although windows has same issue), All i get is this error: Type: SEHException SharpDX.Direct3D11, SharpDX.Direct3D11.DeviceContext::UpdateSubresource So the question remains, is there any other way to update texture from memorybuffer? Preferably something faster and less error prone — Kaminari, Oct 21 '21 at 07:59
The "error" doesn't come from the function itself or the number of times you call it, it comes from your code. — Simon Mourier, Oct 21 '21 at 08:07
@SimonMourier Even if you say this, there surely has to be some way to check this, or a hint where to look. Source pointer is being allocated once. It has constant size = W * H * 4 and when cef does the OnPaint i simply copy entire buffer from there. — Kaminari, Oct 21 '21 at 08:09

score 2 · Accepted Answer · answered Oct 22 '21 at 01:01

2

Solution to this problem was relatively simple yet not so obvious at the beginning.

I simply moved the code responsible for updating texture inside render loop and just keep internal buffer pointer cached.

answered Oct 22 '21 at 01:01

Kaminari

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Updating Texture2D frequently causes process to crash (UpdateSubresource)

1 Answers1