1457246 - Don't hold the sIndirectLayerTreesLock while cloning the WebRenderAPI

Status: RESOLVED FIXED

(Core :: Graphics: WebRender, enhancement)

Description

[Kartikaya Gupta (email:[e-mail])]

We grab the lock at https://searchfox.org/mozilla-central/rev/78dbe34925f04975f16cb9a5d4938be714d41897/gfx/layers/ipc/CrossProcessCompositorBridgeParent.cpp#213 and then clone the API at https://searchfox.org/mozilla-central/rev/78dbe34925f04975f16cb9a5d4938be714d41897/gfx/layers/ipc/CrossProcessCompositorBridgeParent.cpp#239. This is not great, because the cloning process does a blocking call on the render backend thread, and this entangles the two threads unnecessarily. I had a local build where I was trying some scene builder changes and those changes combined with this triggered a deadlock which I think is easily avoidable.

Comment 1

[Kartikaya Gupta (email:[e-mail])]

Attachment: Bug 1457246 - Don't hold the sIndirectLayerTreesLock while making synchronous calls to the RenderBackend thread.

Review commit: https://reviewboard.mozilla.org/r/240118/diff/#index_header
See other reviews: https://reviewboard.mozilla.org/r/240118/

Comment 2

[Sotaro Ikeda [:sotaro]]

Comment on attachment 8971363 [details]
Bug 1457246 - Don't hold the sIndirectLayerTreesLock while making synchronous calls to the RenderBackend thread.

https://reviewboard.mozilla.org/r/240118/#review245982

Looks good. Good catch!

Comment 3

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/d52b265b6b52
Don't hold the sIndirectLayerTreesLock while making synchronous calls to the RenderBackend thread. r=sotaro

Comment 4

[Cosmin Sabou [:CosminS]]

https://hg.mozilla.org/mozilla-central/rev/d52b265b6b52