1482279 - Stop using forcePermissiveCOWs

Status: RESOLVED FIXED

(Testing :: Mochitest, enhancement)

Description

[Kris Maglione [:kmag]]

We'd like to remove platform support for permissive COWs, which means SpecialPowers needs to stop using them.

This should be relatively simple. It just requires that we wrapper proxies in the content compartment rather than in the SpecialPowers global, and then call SpecialPowers.wrap on the SpecialPowers object before we expose it.

In all likelihood, this will actually simplify a lot of code, since we won't have to manually wrap anything we return from SpecialPowers APIs. The proxy will handle it all transparently.

Comment 1

[Masatoshi Kimura [:emk]]

Attachment: Bug 1482279 - Stop using Cu.forcePermissiveCOWs() in SpecialPowers. r?kmag

Comment 2

[Masatoshi Kimura [:emk]]

Attachment: Bug 1482279 - Stop using Cu.forcePermissiveCOWs() in test_resize_move_windows.xhtml. r?kmag

Comment 3

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/9bd1d9cca860
Stop using Cu.forcePermissiveCOWs() in test_resize_move_windows.xhtml. r=kmag

Comment 4

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/a845717e4d10
Stop using Cu.forcePermissiveCOWs() in SpecialPowers. r=kmag

Comment 5

[Pulsebot]

Backout by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/d5c77659d412
Backed out changeset a845717e4d10 for causing multiple failures.

Comment 6

[Alexandru Michis [:malexandru]]

Backed out changeset a845717e4d10 for causing multiple failures.

Backout link: https://hg.mozilla.org/integration/autoland/rev/d5c77659d412d28268519c1add754776fa566c1c

Push with failures:
Mochitest plain failure rate increase:
https://treeherder.mozilla.org/#/jobs?repo=autoland&group_state=expanded&searchStr=mochitest%2Cplain&fromchange=1e7e97b9c413a5a135eef8bfe7151d44fd7fc2eb&tochange=c83c52541dd21556eb3afabf64a0960891e17f0d&selectedTaskRun=ecMcjY7kSTS-NDztDCOXBw-0

Failure logs:

• https://treeherder.mozilla.org/logviewer.html#/jobs?job_id=303431835&repo=autoland&lineNumber=1737
• https://treeherder.mozilla.org/logviewer.html#/jobs?job_id=303428011&repo=autoland&lineNumber=4527
• https://treeherder.mozilla.org/logviewer.html#/jobs?job_id=303425755&repo=autoland&lineNumber=3792
• https://treeherder.mozilla.org/logviewer.html#/jobs?job_id=303429720&repo=autoland&lineNumber=6336

Also seeing mda failures, will update.

Comment 7

[Alexandru Michis [:malexandru]]

mda failures in test_audioContextGC.html:
https://treeherder.mozilla.org/#/jobs?repo=autoland&group_state=expanded&searchStr=%28mda&fromchange=1e7e97b9c413a5a135eef8bfe7151d44fd7fc2eb&tochange=c83c52541dd21556eb3afabf64a0960891e17f0d

Failure log: https://treeherder.mozilla.org/logviewer.html#/jobs?job_id=303427134&repo=autoland&lineNumber=4168

Comment 8

[Natalia Csoregi [:nataliaCs]]

https://hg.mozilla.org/mozilla-central/rev/9bd1d9cca860

Comment 9

[Masatoshi Kimura [:emk]]

• Some mochitest failed only when snapshotWindowWithOptions returned a promise because it was unwrapped.
• getGroupTopLevelWindows would wrap return values. It caused Android test failures. Since it is difficult to unwrap iterated values from Generator functions and NavigationUtils.js is the only caller of getGroupTopLevelWindows, I'll manually unwrap the value to fix the problem.
• attachToWindow would always wrap the SpecialPowers object itself even if the page does not actually use SpecialPowers at all. It had some bad effects to browser-chrome tests. I'll lazify the SpecialPowers object to fix the problem.
• WeakMap (or at least our implementation thereof) does not work well with cross-global WeakMap keys. I'll reduce and tweak WeakMap usages to mitigate problems.

Comment 10

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/f9cdd88decde
Stop using Cu.forcePermissiveCOWs() in SpecialPowers. r=kmag

Comment 11

[Cristian Brindusan [:cbrindusan]]

https://hg.mozilla.org/mozilla-central/rev/f9cdd88decde

Comment 12

[Jan Varga [:janv]]

Can you please update the comment at [1] to reflect the wrapping/unwrapping behavior after changes made in this bug ?
Especially the second paragraph.
Thanks.

[1] https://searchfox.org/mozilla-central/rev/fac90408bcf52ca88a3dcd2ef30a379b68ab24e2/dom/quota/test/common/content.js#19

Comment 13

[Masatoshi Kimura [:emk]]

Attachment: Bug 1482279 - Update the comment in dom/quota/test/common/content.js. r=asuth

Since content has no access to chrome-privileged objects without permissive
COWs, we can no longer unwrap the methods anymore. On the other hand,
SpecialPowers wrapper improved so that we don't have to unwrap the return
value from getAsArrayBuffer() manually.

Comment 14

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/4d54e6681654
Update the comment in dom/quota/test/common/content.js. r=asuth

Comment 15

[Bogdan Tara[:bogdan_tara | bogdant]]

https://hg.mozilla.org/mozilla-central/rev/4d54e6681654