1647319 - Create an abstraction for nested iteration

Status: RESOLVED FIXED

(Core :: JavaScript: GC, enhancement, P1)

Description

[Jon Coppeard (:jonco)]

There are several places where we write an iterator class that combines two other iterators such that it yields all x from iterator X(y) for all y from iterator Y. I've heard this called nested iteration but I don't know if there's a better name.

We should factor out the logic for this to save reimplementing it everywhere.

Comment 1

[Jon Coppeard (:jonco)]

Attachment: Bug 1647319 - Split off NonAtomZonesIter from ZonesIter and add AllZonesIter r?sfink

It's useful in later patches to have zone iterators whose constructors take a single parameter.

Comment 2

[Jon Coppeard (:jonco)]

Attachment: Bug 1647319 - Add NestedIterator template class r?sfink

Depends on D80482

Comment 3

[Jon Coppeard (:jonco)]

Attachment: Bug 1647319 - Use NestedIterator to implement public iterators for realms and compartments r?sfink

Depends on D80483

Comment 4

[Jon Coppeard (:jonco)]

Attachment: Bug 1647319 - GCZones constructor doesn't need to take ZoneSelector parameter r?sfink

There's only one place this is called with SkipAtoms and it's fine to include the atoms zone there.

Depends on D80484

Comment 5

[Jon Coppeard (:jonco)]

Attachment: Bug 1647319 - Use NestedIterator to implement ZoneAllCellIter r?sfink

This also means we can simplify ArenaCellIter is it doesn't need to support reset() any more. I had to rename the getCell/get methods returning TenuredCell*/T* to get/as to make this work.

I also changed use of |ArenaCellIter i| to |ArenaCellIter cell|, like we do for ZonesIter.

Depends on D80485

Comment 6

[Jon Coppeard (:jonco)]

Attachment: Bug 1647319 - Use NestedIterator to implement ArenasToUnmark r?sfink

Depends on D80486

Comment 7

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/1adf40ab95b9
Split off NonAtomZonesIter from ZonesIter and add AllZonesIter r=sfink
https://hg.mozilla.org/integration/autoland/rev/bd0b3614efcf
Add NestedIterator template class r=sfink
https://hg.mozilla.org/integration/autoland/rev/0e900e18ead7
Use NestedIterator to implement public iterators for realms and compartments r=sfink
https://hg.mozilla.org/integration/autoland/rev/32b62f886374
GCZones constructor doesn't need to take ZoneSelector parameter r=sfink
https://hg.mozilla.org/integration/autoland/rev/61916f49f2b3
Use NestedIterator to implement ZoneAllCellIter r=sfink
https://hg.mozilla.org/integration/autoland/rev/cf488a06921e
Use NestedIterator to implement ArenasToUnmark r=sfink

Comment 8

[Cristina Coroiu [:ccoroiu]]

Backed out 6 changesets (bug 1647319) for build bustage at gecko/js/src/gc/GC-inl.h

Backout: https://hg.mozilla.org/integration/autoland/rev/17e8b5e9f8f90c12561f8552d779567895301e0e

Failure push: https://treeherder.mozilla.org/#/jobs?repo=autoland&revision=cf488a06921ec04de214013170daf0aca6a83ff6

Failure logs:
https://treeherder.mozilla.org/logviewer.html#/jobs?job_id=307216889&repo=autoland&lineNumber=7200

https://treeherder.mozilla.org/logviewer.html#/jobs?job_id=307216905&repo=autoland&lineNumber=2082

Comment 9

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/4a59ad84db1b
Split off NonAtomZonesIter from ZonesIter and add AllZonesIter r=sfink
https://hg.mozilla.org/integration/autoland/rev/8624539378e1
Add NestedIterator template class r=sfink
https://hg.mozilla.org/integration/autoland/rev/791dfca7e74d
Use NestedIterator to implement public iterators for realms and compartments r=sfink
https://hg.mozilla.org/integration/autoland/rev/fe6e1d55aa8f
GCZones constructor doesn't need to take ZoneSelector parameter r=sfink
https://hg.mozilla.org/integration/autoland/rev/17c17458be2e
Use NestedIterator to implement ZoneAllCellIter r=sfink
https://hg.mozilla.org/integration/autoland/rev/9ba80352f5c3
Use NestedIterator to implement ArenasToUnmark r=sfink

Comment 10

[Dorel Luca [:dluca]]

https://hg.mozilla.org/mozilla-central/rev/4a59ad84db1b
https://hg.mozilla.org/mozilla-central/rev/8624539378e1
https://hg.mozilla.org/mozilla-central/rev/791dfca7e74d
https://hg.mozilla.org/mozilla-central/rev/fe6e1d55aa8f
https://hg.mozilla.org/mozilla-central/rev/17c17458be2e
https://hg.mozilla.org/mozilla-central/rev/9ba80352f5c3