1071721 - SettingsLock objects leak by only calling destroyDOMRequestHandler during inner-window-closed

Status: RESOLVED FIXED

(Core :: DOM: Device Interfaces, defect)

Description

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

[Blocking Requested - why for this release]:

SettingsLock objects never explicitly call destroyDOMRequestHelper when their existence ends (after receiving an Finalize::OK or Finalize::KO message). This means that the message manager will hold settings locks open until inner-window-destroyed. In the case of B2G, this means that locks existing in background apps (like system) will live forever, causing leaks.

Comment 1

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

Attachment: Patch 1 (v1) - Call destroyDOMRequestHelper on SettingsLock after transaction ends

Comment 2

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

Checked this by flashing flame, going through FTU, then running get_about_memory.py and looking for open settings locks (basically, grepping for "SettingsLock <no private>":

Before patch - 187 occurrences
After patch - 8 occurrences

I'm going to do root traces on the 8 occurrences after the patch to make sure those aren't leaks too, but there's a good chance those are just locks held by various objects as members or something.

Comment 3

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

Comment on attachment 8493889 [details] [diff] [review]
Patch 1 (v1) - Call destroyDOMRequestHelper on SettingsLock after transaction ends

Approval Request Comment
[Feature/regressing bug #]: Bug 900551
[User impact if declined]: Memory leaks
[Describe test coverage new/current, TBPL]: It's believed that this currently takes down stability testing, so if that works...
[Risks and why]: None
[String/UUID change made/needed]: None

Comment 4

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

https://hg.mozilla.org/integration/b2g-inbound/rev/3c4b65dc595a

Comment 5

[Ryan VanderMeulen [:RyanVM]]

Kyle landed this on Aurora.
https://hg.mozilla.org/releases/mozilla-aurora/rev/96e15bbed7ab

Comment 6

[Ryan VanderMeulen [:RyanVM]]

https://hg.mozilla.org/mozilla-central/rev/3c4b65dc595a