1592031 - Make profiler screenshots work in the WR OS compositor configuration on macOS

Status: RESOLVED FIXED

(Core :: Graphics: WebRender, enhancement, P3)

Description

[Markus Stange [:mstange]]

Similar to bug 1592026, but with the added challenge that the readback needs to be as low-overhead and "non-blocking" as possible.

Comment 1

[Jessie [:jbonisteel] pls NI]

We can likely enable our compositor work in Nightly before fixing this, we should not let it ride to release until we fix.

Comment 2

[Sotaro Ikeda [:sotaro]]

:mstange, is there a document about how to use "window recording"? I could not find it. The window recording was added by Bug 1536174.

• https://searchfox.org/mozilla-central/rev/923eec8d2fb8078ebc7a33a9e1ce73eac01f7446/browser/base/content/browser-sets.inc#336

Comment 3

[Markus Stange [:mstange]]

It is used by browsertime when measuring "visual metrics" for pageload performance. But the simplest way to play with it is from the browser console. First, create a string pref with the name layers.windowrecording.path and set it to an absolute path to some directory. Then, restart Firefox, open the Browser Console (with devtools.chrome.enabled = true), and execute the following:

windowUtils.startCompositionRecording()
// now briefly interact with a web site in the browser, and then run:
windowUtils.stopCompositionRecording(true)

A new folder in the chosen directory should appear and be populated with PNG files which contain screenshots from the Firefox window.

Comment 4

[Sotaro Ikeda [:sotaro]]

Great! Thank you.

Comment 5

[Markus Stange [:mstange]]

Attachment: Bug 1592031 - Rename CompositorScreenshotGrabber to ScreenshotGrabber and give it a more generic interface. r=mattwoodrow

Comment 6

[Markus Stange [:mstange]]

Attachment: Bug 1592031 - Add profiler screenshots functionality to NativeLayerSnapshotter. r=mattwoodrow

Depends on D59157

Comment 7

[Markus Stange [:mstange]]

Attachment: Bug 1592031 - Use NativeLayerSnapshotter to capture profiler screenshots with WebRender on macOS. r=mattwoodrow

Depends on D59158

Comment 8

[Kris Taeleman (:ktaeleman)]

@Markus: Should this block Mac release?

Comment 9

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/925e3b179b9b
Rename CompositorScreenshotGrabber to ScreenshotGrabber and give it a more generic interface. r=mattwoodrow
https://hg.mozilla.org/integration/autoland/rev/5db68a6a5bc2
Add profiler screenshots functionality to NativeLayerSnapshotter. r=mattwoodrow
https://hg.mozilla.org/integration/autoland/rev/19145f742503
Use NativeLayerSnapshotter to capture profiler screenshots with WebRender on macOS. r=mattwoodrow

Comment 10

[Narcis Beleuzu [:NarcisB]]

Backed out for bustages on ScreenshotGrabber.h

Backout link: https://hg.mozilla.org/integration/autoland/rev/37eb71de7e8a1c16b2f222a14c9e91669ed49fbf
Log link: https://treeherder.mozilla.org/logviewer.html#/jobs?job_id=313709954&repo=autoland&lineNumber=20883

Comment 11

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/203d7e09574c
Rename CompositorScreenshotGrabber to ScreenshotGrabber and give it a more generic interface. r=mattwoodrow
https://hg.mozilla.org/integration/autoland/rev/6b2299a3cd00
Add profiler screenshots functionality to NativeLayerSnapshotter. r=mattwoodrow
https://hg.mozilla.org/integration/autoland/rev/eb44242ad435
Use NativeLayerSnapshotter to capture profiler screenshots with WebRender on macOS. r=mattwoodrow

Comment 12

[Cristina Coroiu [:ccoroiu]]

https://hg.mozilla.org/mozilla-central/rev/203d7e09574c
https://hg.mozilla.org/mozilla-central/rev/6b2299a3cd00
https://hg.mozilla.org/mozilla-central/rev/eb44242ad435

Comment 13

[Markus Stange [:mstange]]

(In reply to Kris Taeleman (:ktaeleman) from comment #8)

@Markus: Should this block Mac release?

Yes, it should. It's causing confusion for users of the profiler, and sometimes even crashes.

Comment 14

[Markus Stange [:mstange]]

The patches in this bug ended up only fixing the profiler screenshots aspect, and not the frame recording API. I filed bug 1664049 on the frame recording part.