1599965 - Improve how dirty image detection works in webrender

Status: RESOLVED FIXED

(Core :: Graphics: WebRender, enhancement)

Comment 1

[Glenn Watson [:gw]]

Attachment: Bug 1599965 - Improve how dirty image detection works in webrender.

• The existing code to detect if an image is dirty fails in some
  cases. For external images, they were not being added to the
  list of dirty images when update was called. Further, since
  the dirty image keys hash set was cleared each frame, it was
  possible for an image to become dirty, but this detection to be
  missed if it is not queried until a subsequent frame (due to
  it being off-screen.

  Instead, each image template has a generation identifier that
  is incremented whenever an image template is updated. The picture
  caching code stores the generation of the image key when it was
  rasterized, and compares that to the current image key generation
  when comparing dependencies. This fixes both cases above.

• Remove the is_cacheable logic that was previously used to
  invalidate picture cache tiles for external images. This would
  result in picture cache images that intersect with videos being
  invalidated every frame unconditionally. However, this code path
  is no longer required, due to the change above. By relying on
  the true image dirty check, we can skip invalidating tiles
  affected by video if the video frame has not advanced (e.g. it
  is paused, or advancing at a lower frame rate than we are
  currently compositing at).

Comment 2

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/93ccc760c4dd
Improve how dirty image detection works in webrender. r=nical

Comment 3

[Stefan Hindli [:stefan_hindli]]

https://hg.mozilla.org/mozilla-central/rev/93ccc760c4dd

Comment 4

[Stefan Hindli [:stefan_hindli]]

Backed out changeset 93ccc760c4dd (Bug 1599965) for causing wrench bustage on central CLOSED TREE a=backout

https://treeherder.mozilla.org/#/jobs?repo=mozilla-central&resultStatus=testfailed%2Cbusted%2Cexception&selectedJob=279269351

https://treeherder.mozilla.org/logviewer.html#/jobs?job_id=279269351&repo=mozilla-central&lineNumber=1316

Comment 5

[Pulsebot]

Backout by [e-mail]:
https://hg.mozilla.org/mozilla-central/rev/7205934173a4
Backed out changeset 93ccc760c4dd for causing wrench bustage on central CLOSED TREE a=backout

Comment 6

[Glenn Watson [:gw]]

I don't understand how that failure is caused by this patch - it seems like some kind of compile error in a dependency that is unrelated to this change? It also passed on a try run on that configuration.

I'll take a closer look tomorrow and see if I can work out what's going on.

Comment 7

[Glenn Watson [:gw]]

(this is the try run with this patch which seems to pass on that failing wrench platform - https://treeherder.mozilla.org/#/jobs?repo=try&revision=05d9b43469e8f6d0d9acc04b60f305f8392b3202&selectedJob=278974255)

Comment 8

[Glenn Watson [:gw]]

I suspect the problem may actually be caused by / related to https://bugzilla.mozilla.org/show_bug.cgi?id=1595218 which landed recently?

Comment 9

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/mozilla-central/rev/f19ecba85c93
Improve how dirty image detection works in webrender. r=nical