1042513 - Clearing timer in Firefly shutdown is racy and not needed

Status: RESOLVED FIXED

(Firefox for Android Graveyard :: Screencasting, defect)

Description

[Mark Finkle (:mfinkle) (use needinfo?)]

Attachment: firefly-fix v0.1

I get an exception almost every time I try to shutdown a Firefly video casting session:
E/GeckoConsole(29571): [JavaScript Error: "TypeError: this._info_timer.clear is not a function" {file: "resource://gre/modules/FireflyApp.jsm" line: 307}]

Looking at this in the debugger, this.info_timer is null but flips as I step over to the next line. It's racing with the timer's timeout itself.

Thinking about this more, shutdown is only requesting a shutdown from the receiver. It's not any different than requesting a pause or play, and we don't kill the timer before those. There should be no reason we need to clear the timer and removing it doesn't show any errors - but does allow a normal shutdown to happen.

Comment 1

[Mark Finkle (:mfinkle) (use needinfo?)]

I should note that the exception I get when attempting to shutdown means the video session does not shutdown. I have to keep tapping the button until I will the race.

With the patch, it's not a problem.

Comment 2

[Mark Finkle (:mfinkle) (use needinfo?)]

https://hg.mozilla.org/integration/fx-team/rev/ac723928f295

Comment 3

[Mark Finkle (:mfinkle) (use needinfo?)]

Comment on attachment 8460743 [details] [diff] [review]
firefly-fix v0.1

Approval Request Comment
[Feature/regressing bug #]:
[User impact if declined]: Video casting session won't shutdown
[Describe test coverage new/current, TBPL]: Working fine in Nightly
[Risks and why]: low
[String/UUID change made/needed]: none

Comment 4

[Mark Finkle (:mfinkle) (use needinfo?)]

landed in m-c on 7/23:
http://hg.mozilla.org/mozilla-central/rev/ac723928f295

Comment 5

[Mark Finkle (:mfinkle) (use needinfo?)]

https://hg.mozilla.org/releases/mozilla-aurora/rev/8c70620fe68b