957769 - FTU Network Scanning causes infinite Scanning For Networks screen

Status: RESOLVED FIXED

(Firefox OS Graveyard :: Gaia::First Time Experience, defect)

Description

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

Repro:

- Turn off wifi capabilities on computer
- Create a clean gaia profile with ftu enabled
- Start B2G Desktop
- Choose Language

Expected:

Scanning For Networks screen quickly pops up then goes away.

Actual:

Scanning For Networks screen stays up forever. Stopping and restarting B2G process sometimes seems to unwedge it.

This error message seems to pop up whenever it hits the infinite spinlock state, not sure if relevant:

[22268] WARNING: Failed to terminate!: file /share/mozbuild/gecko-dev/dom/workers/WorkerPrivate.cpp, line 2621
[22268] WARNING: A control runnable was posted to a worker that is already shutting down!: file /share/mozbuild/gecko-dev/dom/workers/WorkerPrivate.cpp, line 2236
[22268] WARNING: A control runnable was posted to a worker that is already shutting down!: file /share/mozbuild/gecko-dev/dom/workers/WorkerPrivate.cpp, line 2236

Comment 1

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

gwagner says error message was already there so may not be relevant. Changing title to not infer cause.

Comment 2

[Gregor Wagner [:gwagner]]

caused by https://github.com/mozilla-b2g/gaia/commit/8a11c889ce5b078133ea14f919032db043d2221a

Comment 3

[Jason Smith [:jsmith]]

Is it possible for this bug to reproduce on device?

Comment 4

[Gregor Wagner [:gwagner]]

(In reply to Jason Smith [:jsmith] from comment #3)
> Is it possible for this bug to reproduce on device?

Good point. It only reproduces with debug builds.

We could insert some timeout for testing to make sure that this can never happen on the device.

Comment 5

[Michael Henretty [:mikehenrty][:mhenretty]]

The problem stems from two things, first: we are showing and then hiding the "Scanning" overlay twice, and second: hiding the overlay can _sometimes_ be asynchronous (depending on animation state).

We show/hide this overlay twice when we skip the "Enable Cell Data" step (happens when no SIM is present). This in turn causes the navigation logic to set the hash twice (once before skipping once after), which then causes two wifi scans, and two overlay show/hides.

AFAICT, this double show/hide has always happened, but my patch changed the timing between the two show/hides which caused this bug. If this is true, the fix is easy: don't set the hash twice. I'll upload a patch for this and ask Kyle to see if that fixes the issue for him too.

Comment 6

[Michael Henretty [:mikehenrty][:mhenretty]]

Attachment: Test Solution

Kyle, could you test and see if this patch fixes it for you?

Comment 7

[Michael Henretty [:mikehenrty][:mhenretty]]

Comment on attachment 8358129 [details]
Test Solution

Looks like this is still broken, clearing the FB from Kyle until I come up with something better.

Comment 8

[Michael Henretty [:mikehenrty][:mhenretty]]

Comment on attachment 8358129 [details]
Test Solution

Lets try this again, does this work for you Kyle or Gregor?

Comment 9

[Michael Henretty [:mikehenrty][:mhenretty]]

Comment on attachment 8358129 [details]
Test Solution

Fernando, could you take a look at this patch for fixing infinite wifi scanning? Cause of the bug is listed in comment 5.

Comment 10

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

Comment on attachment 8358129 [details]
Test Solution

Seems to work well for me. Clicked through navigation in a few different ways and couldn't break it on b2g-desktop on a machine with no wifi.

Comment 11

[Michael Henretty [:mikehenrty][:mhenretty]]

Comment on attachment 8358129 [details]
Test Solution

Updated the pull request to address a case where shimless B2G-desktop still caused this issue.

Comment 12

[Fernando Campo (:fcampo)]

Comment on attachment 8358129 [details]
Test Solution

Patch looks nice, and after testing it I'm unable to repro. R+ with couple of minimal nits.
Thanks for fixing it.

Comment 13

[Michael Henretty [:mikehenrty][:mhenretty]]

master: https://github.com/mozilla-b2g/gaia/commit/4cc2dcbf9cebf6d4731783626acf57c3e712f479