1435995 - DXGI_SWAP_EFFECT_FLIP_SEQUENTIAL makes HWND unreusable

Status: RESOLVED FIXED

(Core :: Graphics: WebRender, enhancement, P1)

Description

[Sotaro Ikeda [:sotaro]]

This bug is created based on Bug 1435693 comment 3.

RenderCompositorANGLE uses DXGI_SWAP_EFFECT_FLIP_SEQUENTIAL swap chain for performance. But it seems to make HWND unreusable. When WebRender fallback to normal compositor. The compositor could not update HWND's window.

Comment 1

[Sotaro Ikeda [:sotaro]]

If we want to use DXGI_SWAP_EFFECT_FLIP_SEQUENTIAL, it seems necessary to use DComp with child window.

Comment 2

[Sotaro Ikeda [:sotaro]]

(In reply to Sotaro Ikeda [:sotaro] from comment #0)
> This bug is created based on Bug 1435693 comment 3.
> 

Copy of Bug 1435693 comment 3.

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When WebRender was fallback to normal compositor, the compositor seems to work as normal, but window was not updated. I tried a lot of RenderCompositorANGLE code modification patterns to find out a cause of it. It seems that DXGI_SWAP_EFFECT_FLIP_SEQUENTIAL seems to cause the problem. When I changed DXGI_SWAP_EFFECT_FLIP_SEQUENTIAL to DXGI_SWAP_EFFECT_SEQUENTIAL, the window update problem did not happen.

MDN has the following. It seems to be related.

 > Use one flip model swap chain per HWND. Do not target multiple flip model swap chains to the same HWND.
 https://msdn.microsoft.com/ja-jp/library/windows/desktop/hh706346

Comment 3

[Sotaro Ikeda [:sotaro]]

CompositorD3D11 and MLGSwapChainD3D11 also has a capability of using DXGI_SWAP_EFFECT_FLIP_SEQUENTIAL(pref gfx.direct3d11.use-double-buffering). It is disabled by default.

When it was enabled and did fallback from CompositorD3D11 to BasicCompositor. BasicCompositor could not update window. The same problem happened.

Comment 4

[Sotaro Ikeda [:sotaro]]

It seems better to disable DXGI_SWAP_EFFECT_FLIP_SEQUENTIAL for now.

Comment 5

[Sotaro Ikeda [:sotaro]]

Attachment: patch - Disable DXGI_SWAP_EFFECT_FLIP_SEQUENTIAL usage

Comment 6

[Nicolas Silva [:nical]]

Comment on attachment 8948653 [details] [diff] [review]
patch - Disable DXGI_SWAP_EFFECT_FLIP_SEQUENTIAL usage

Review of attachment 8948653 [details] [diff] [review]:
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Nice catch!

Comment 7

[Sotaro Ikeda [:sotaro]]

https://treeherder.mozilla.org/#/jobs?repo=try&revision=e59bed1d13045e10c208c7bd10a9a377068d84e6

Comment 8

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/mozilla-inbound/rev/1157f9e6cce0
Disable DXGI_SWAP_EFFECT_FLIP_SEQUENTIAL usage r=nical

Comment 9

[Andrei Ciure[:aciure]]

https://hg.mozilla.org/mozilla-central/rev/1157f9e6cce0