753175 - Race condition in Sync Migration / Preference:Get

Status: RESOLVED FIXED

(Firefox for Android Graveyard :: General, defect)

Description

[Gian-Carlo Pascutto [:gcp]]

https://bugzilla.mozilla.org/show_bug.cgi?id=752907#c9

Profile Migrator should not unregister its Preferences event listener until it actually received the preferences it asked for. It will currently get confused if someone else requests preferences at the same time.

D/ProfileMigrator( 1410): Received event: Preferences:Data
W/ProfileMigrator( 1410): Could not recover setting for = ui.zooming.animation_frames

Comment 1

[Matt Brubeck (:mbrubeck)]

Nominating for blocking because this can prevent profile migration from finishing successfully.

Comment 2

[:Margaret Leibovic]

Attachment: patch

Comment 3

[:Margaret Leibovic]

I tested this patch with the STR from bug 752907 comment 0, and it indeed fixes the sync migration problem.

Comment 4

[Gian-Carlo Pascutto [:gcp]]

Comment on attachment 622221 [details] [diff] [review]
patch

Review of attachment 622221 [details] [diff] [review]:
-----------------------------------------------------------------

Our Preferences:Get design won't hold up in the long run. If you would fire a request for only one of the preferences elsewhere, we'd still misfire and think this was a reply to our request. We'll have to keep this in mind for the longer term.

::: mobile/android/base/ProfileMigrator.java
@@ +456,5 @@
>                      JSONObject jPref = jsonPrefs.getJSONObject(i);
>                      final String prefName = jPref.getString("name");
> +
> +                    // Check to make sure we're working with preferences we requested.
> +                    if (!Arrays.asList(SYNC_SETTINGS_LIST).contains(prefName))

I think this is guaranteed to be in mSyncSettingsList already.

Comment 5

[Kartikaya Gupta (email:[e-mail])]

> Our Preferences:Get design won't hold up in the long run. If you would fire
> a request for only one of the preferences elsewhere, we'd still misfire and
> think this was a reply to our request. We'll have to keep this in mind for
> the longer term.

Yeah, I ran into this problem when adding prefs to GeckoLayerClient and PanZoomController. I've filed bug 753312 for it.

Comment 6

[Gian-Carlo Pascutto [:gcp]]

Comment on attachment 622221 [details] [diff] [review]
patch

[Approval Request Comment]
User impact if declined: Sync will not migrate successfully dependent on timing.

Comment 7

[:Margaret Leibovic]

https://hg.mozilla.org/integration/mozilla-inbound/rev/228971745c99

Comment 8

[:Margaret Leibovic]

https://hg.mozilla.org/releases/mozilla-aurora/rev/1ad62534690f

Comment 9

[Ed Morley [:emorley]]

https://hg.mozilla.org/mozilla-central/rev/228971745c99