1670014 - Delay querying buffer age until necessary

Status: RESOLVED FIXED

(Core :: Graphics: WebRender, defect)

Description

[Jamie Nicol [:jnicol] out of office until 6th Jan]

Currently we query the backbuffer's age in RenderCompositorEGL::BeginFrame(). This makes the driver dequeue a backbuffer, which may cause the driver to block until a buffer is available. (See bug 1668878.) We should delay calling this until necessary (in Renderer::composite_simple()) to increase the chances that the backbuffer is available.

Comment 1

[Jamie Nicol [:jnicol] out of office until 6th Jan]

Attachment: Bug 1670014 - Delay querying buffer age until it is actually needed. r?sotaro

Currently we query the backbuffer age in
RenderCompositor::BeginFrame(). Querying the age on android requires
the driver to dequeue a new backbuffer. By doing this right at the
start of the frame, we may cause the driver to block until a buffer is
ready.

We don't actually need the buffer age until part way through
rendering, in Renderer::composite_simple(), by which point there is a
bette chance the buffer is availible. So move the query to there instead.

Comment 2

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/28d4ff01fac3
Delay querying buffer age until it is actually needed. r=sotaro

Comment 3

[Cristina Coroiu [:ccoroiu]]

https://hg.mozilla.org/mozilla-central/rev/28d4ff01fac3