809533 - make nsPresArena and display list arena use infallible allocation

Status: RESOLVED FIXED

(Core :: Layout, defect)

Description

[David Baron :dbaron: (⌚️UTC-5, no longer working on Mozilla)]

We should make nsPresArena and the display list arena be infallible allocators; they allocate memory in small pieces and many of the existing callers don't handle out-of-memory.  So they should just abort on allocation failure.

Comment 1

[David Baron :dbaron: (⌚️UTC-5, no longer working on Mozilla)]

Attachment: , patch 1: Make allocation in the frame arena and the display list arena infallible.

Comment 2

[David Baron :dbaron: (⌚️UTC-5, no longer working on Mozilla)]

Attachment: , patch 2: Don't null-check inside NS_New*Frame.

Comment 3

[David Baron :dbaron: (⌚️UTC-5, no longer working on Mozilla)]

Attachment: , patch 3: Stop handling allocation failures in the style system that no longer need to be handled.

Comment 4

[David Baron :dbaron: (⌚️UTC-5, no longer working on Mozilla)]

Attachment: , patch 4: Remove null-checks of NS_New*Frame callers in the frame constructor.

Comment 5

[Nathan Froyd [:froydnj]]

You should remove:

http://mxr.mozilla.org/mozilla-central/source/layout/base/nsIPresShell.h#204
http://mxr.mozilla.org/mozilla-central/source/layout/base/nsIPresShell.h#232

too.

Comment 6

[David Baron :dbaron: (⌚️UTC-5, no longer working on Mozilla)]

Landed patches 1 and 2 ahead of bug 572200:
remote:   https://hg.mozilla.org/integration/mozilla-inbound/rev/6e5f31366aab
remote:   https://hg.mozilla.org/integration/mozilla-inbound/rev/cf16f2f84efc

Comment 7

[David Baron :dbaron: (⌚️UTC-5, no longer working on Mozilla)]

Attachment: , patch 5: Remove unneeded null-checks in nsIPresShell.h.

Comment 8

[Ryan VanderMeulen [:RyanVM]]

https://hg.mozilla.org/mozilla-central/rev/6e5f31366aab
https://hg.mozilla.org/mozilla-central/rev/cf16f2f84efc

Comment 9

[Boris Zbarsky [:bzbarsky]]

Comment on attachment 679251 [details] [diff] [review]
, patch 3:  Stop handling allocation failures in the style system that no longer need to be handled.

r=me.  Nice to see all that code go away!

Comment 10

[Boris Zbarsky [:bzbarsky]]

Comment on attachment 679252 [details] [diff] [review]
, patch 4:  Remove null-checks of NS_New*Frame callers in the frame constructor.

>+      // XXXldb Can we remove this now?

Yes.

r=me, but I bet there are lots of methods returning nsresult that can stop doing that now... Maybe file a followup to clean that up?

Comment 11

[David Baron :dbaron: (⌚️UTC-5, no longer working on Mozilla)]

Landed patch 3 through patch 5:
remote:   https://hg.mozilla.org/integration/mozilla-inbound/rev/c6e38e325158
remote:   https://hg.mozilla.org/integration/mozilla-inbound/rev/0be0f375cac8
remote:   https://hg.mozilla.org/integration/mozilla-inbound/rev/d6c8276fe88e


Note that patch 5 addresses comment 5.

Comment 12

[David Baron :dbaron: (⌚️UTC-5, no longer working on Mozilla)]

Comment on attachment 679249 [details] [diff] [review]
, patch 1:  Make allocation in the frame arena and the display list arena infallible.

[Approval Request Comment]
Bug caused by (feature/regressing bug #): N/A
User impact if declined: Unable to land significant B2G performance improvement in bug 572200 without potentially risky logic changes.
Testing completed (on m-c, etc.): on mozilla-central
Risk to taking this patch (and alternatives if risky): The risk should be low; it's just applying the concept of infallible memory allocations which we already use extensively to one new class of small memory allocations.
String or UUID changes made by this patch: None.

Comment 13

[bhavana bajaj [:bajaj]]

Comment on attachment 679249 [details] [diff] [review]
, patch 1:  Make allocation in the frame arena and the display list arena infallible.

Approving on aurora as I understand it helps with b2g performance

Comment 14

[Ryan VanderMeulen [:RyanVM]]

https://hg.mozilla.org/mozilla-central/rev/c6e38e325158
https://hg.mozilla.org/mozilla-central/rev/0be0f375cac8
https://hg.mozilla.org/mozilla-central/rev/d6c8276fe88e

Comment 15

[David Baron :dbaron: (⌚️UTC-5, no longer working on Mozilla)]

https://hg.mozilla.org/releases/mozilla-aurora/rev/fae3b9538755