1648631 - L10nRegistryService._synchronizeSharedData does not flush until the main thread is idle

Status: RESOLVED FIXED

(Core :: Internationalization, defect, P1)

Description

[(No longer employed by Mozilla) Aaron Klotz]

L10nRegistryService._synchronizeSharedData() ends up calling mozilla::dom::ipc::WritableSharedMap::Set which sets a value in the map but does not immediately flush; instead it calls the private WritableSharedMap::KeyChanged method which queues up an idle-priority runnable to flush.

AFAICT this is what is causing various intermittent test failures in browser_resource_uri.js: the setting up of the mock source will not make it to the content process at the correct time if the parent main thread never gets a chance to sit idle.

Preallocation of content processes makes it less likely that the main thread will idle, since it doesn't need to wait for a new content process to start.

Comment 1

[(No longer employed by Mozilla) Aaron Klotz]

Attachment: Bug 1648631: Part 1 - Make L10nRegistryService._synchronizeSharedData() explicitly flush and convert source registration to accept arrays; r=zbraniecki

Setting a key/value pair on the parent process message manager's sharedData
initiates a pending runnable that runs at idle priority. If the current
thread never gets a chance to idle, then those registry changes will never be
synchronized.

This patch adds an explicit flush so that _synchronizeSharedData does indeed
actually synchronize.

Comment 2

[(No longer employed by Mozilla) Aaron Klotz]

Attachment: Bug 1648631: Part 2 - Update Extension.jsm to use the revised L10nRegistry APi; r=#extension-reviewers

Now that the L10nRegistry source registration APIs accept arrays, we modify
this code to work with the revised signature.

Depends on D81243

Comment 3

[(No longer employed by Mozilla) Aaron Klotz]

Attachment: Bug 1648631: Part 3 - Update tests to work with the revised L10nRegistry API; r=zbraniecki!,#extension-reviewers

Depends on D81390

Comment 4

[(No longer employed by Mozilla) Aaron Klotz]

Attachment: Bug 1648631: Part 4 - Update docs to reflect L10nRegistry interface change; r=zbraniecki

Depends on D81391

Comment 5

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/35cf713e8854
Part 1 - Make L10nRegistryService._synchronizeSharedData() explicitly flush and convert source registration to accept arrays; r=zbraniecki
https://hg.mozilla.org/integration/autoland/rev/b8feea0d2f5a
Part 2 - Update Extension.jsm to use the revised L10nRegistry APi; r=robwu
https://hg.mozilla.org/integration/autoland/rev/15afb002fb3b
Part 3 - Update tests to work with the revised L10nRegistry API; r=zbraniecki,robwu
https://hg.mozilla.org/integration/autoland/rev/0a4b3f99d2d1
Part 4 - Update docs to reflect L10nRegistry interface change; r=zbraniecki

Comment 6

[Noemi Erli[:noemi_erli]]

https://hg.mozilla.org/mozilla-central/rev/35cf713e8854
https://hg.mozilla.org/mozilla-central/rev/b8feea0d2f5a
https://hg.mozilla.org/mozilla-central/rev/15afb002fb3b
https://hg.mozilla.org/mozilla-central/rev/0a4b3f99d2d1