Create a shared-memory-friendly version of gfxSparseBitSet to store font character coverage

RESOLVED FIXED in Firefox 68

Status

()

enhancement
P3
normal
RESOLVED FIXED
3 months ago
14 days ago

People

(Reporter: jfkthame, Assigned: jfkthame)

Tracking

unspecified
mozilla68
Points:
---
Dependency tree / graph

Firefox Tracking Flags

(Fission Milestone:M2, firefox68 fixed)

Details

Attachments

(1 attachment)

Assignee

Description

3 months ago

gfxSparseBitSet is not suited to storing in shared memory, because of its use of nsTArray<> members. For the cross-process font list, we want to store character coverage data in the shared memory, so it will be useful to have an object like gfxSparseBitSet, but designed to be usable regardless of the address where it is mapped.

For simplicity, the SharedBitSet introduced here will be frozen once initialized, unlike gfxSharedBitSet which can be updated with set()/clear() operations. The intention is to use gfxSharedBitSet as an accumulator while reading the character coverage info for a font (as we currently do), and then "snapshot" the result into a frozen SharedBitSet for storage in the shared font list.

Assignee

Comment 2

3 months ago

(This is migrated from patch 8 in bug 1514869.)

There's a r+ patch which didn't land and no activity in this bug for 2 weeks.
:jfkthame, could you have a look please?

Flags: needinfo?(jfkthame)

Comment 4

3 months ago
Pushed by jkew@mozilla.com:
https://hg.mozilla.org/integration/autoland/rev/cfbec1b8ef40
Provide a version of gfxSparseBitSet that is better suited to shared-memory use. r=jwatt

Comment 5

3 months ago
bugherder
Status: NEW → RESOLVED
Closed: 3 months ago
Resolution: --- → FIXED
Target Milestone: --- → mozilla68
Assignee

Updated

Last month
Flags: needinfo?(jfkthame)

Updated

14 days ago
Fission Milestone: ? → M2
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