1106896 - Improve mozSettings debugging capabilities

Status: RESOLVED FIXED

(Core :: DOM: Core & HTML, defect)

Description

[:gerard-majax]

We need:
 - debug and verbose level of logging
 - better memory reporting to easily see blockage and leaking

Comment 1

[:gerard-majax]

Attachment: Improve debug and error reporting in mozSettings r=qdot

We break down the logging capabilities into two classes: debug and
verbose. Verbose will help to track everything that happens, while debug
should just report error cases. We also augment memory reports with
values to help tracking potential issues like: queue blockage, leaking,
etc.

Comment 2

[:gerard-majax]

try: https://tbpl.mozilla.org/?tree=Try&rev=79a152fa4544

Comment 3

[Kyle Machulis [:qdot] [:kmachulis] (INACTIVE)]

Should we possibly take this farther and attach stacks to each lock if a certain debug pref is on, so we can trace who is owning them?

Comment 4

[:gerard-majax]

(In reply to Kyle Machulis (OUT OCT 1-NOV 30) [:kmachulis] [:qdot] (USE NEEDINFO?) from comment #3)
> Should we possibly take this farther and attach stacks to each lock if a
> certain debug pref is on, so we can trace who is owning them?

This is something I thought about, yes, but I was not sure about going down this road, given the amount of data this adds. Maybe we can do this in a follow up?

Comment 5

[Carsten Book [:Tomcat]]

https://hg.mozilla.org/integration/mozilla-inbound/rev/9107df18cdd9

Comment 6

[Carsten Book [:Tomcat]]

https://hg.mozilla.org/mozilla-central/rev/9107df18cdd9

Comment 8

[:gerard-majax]

Comment on attachment 8531343 [details] [diff] [review]
Improve debug and error reporting in mozSettings r=qdot

NOTE: Please see https://wiki.mozilla.org/Release_Management/B2G_Landing to better understand the B2G approval process and landings.

[Approval Request Comment]
Bug caused by (feature/regressing bug #): none
User impact if declined: very hard to debug settings api lockup (bug 1105511)
Testing completed: on device and with mulet
Risk to taking this patch (and alternatives if risky): low
String or UUID changes made by this patch: none

Comment 9

[bhavana bajaj [:bajaj]]

Comment on attachment 8531343 [details] [diff] [review]
Improve debug and error reporting in mozSettings r=qdot

Discussed this with :fabice, although non-blocking, keeping in mind that there is no user impact and low risk here, helps a lot in debugging, hence approving this for uplift.

Comment 10

[Ryan VanderMeulen [:RyanVM]]

Needs rebasing for b2g34 uplift.

Comment 11

[:gerard-majax]

Attachment: Improve debug and error reporting in mozSettings. r=qdot

We break down the logging capabilities into two classes: debug and
verbose. Verbose will help to track everything that happens, while debug
should just report error cases. We also augment memory reports with
values to help tracking potential issues like: queue blockage, leaking,
etc.

Comment 12

[:gerard-majax]

Okay, I've already lost more than one hour trying to push this to v2.1 for a try: mercurial does not want to apply my diff even if I generate it from the proper revision ...

Comment 13

[:gerard-majax]

After much fighting, https://tbpl.mozilla.org/?tree=Try&rev=3136e8a8074f

Comment 14

[:gerard-majax]

Branch patch seems ok

Comment 15

[Ryan VanderMeulen [:RyanVM]]

https://hg.mozilla.org/releases/mozilla-b2g34_v2_1/rev/2f2ed06982b1

Comment 16

[:gerard-majax]

Damn, how is it possible nobody spotted this: Services is loaded after we make use of it :(. It's not always working.