High CPU load on Payment screen

[Víctor R. Ruiz]

Test case.
- Go to the Dash.
- Open Ubuntu Store.
- Search for paid apps ("price:2.99").
- Select an unpurchased app.
- Install it.
- Introduce your credentials.

Expected result.
- While the user is on Payment screen, CPU load is not high.

Actual result.
- pay-service process goes over 100% load.

And Arale gets very hot.

current build number: 321
device name: arale
channel: ubuntu-touch/rc-proposed/meizu.en

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Selene ToyKeeper (toykeeper)]

Confirmed, and I'm trying to locate the change which introduced this bug.

[Selene ToyKeeper (toykeeper)]

I bisected this and it turned out to be much older than I expected. Looks like it happened between 2015-09 and 2015-11, though beyond that I'm not sure. We don't have any rc-proposed images old enough for a more fine-grained inspection.

Problem exists in:
* krillin rc-proposed 329 (pay-service 15.10+15.04.20160413-0ubuntu1)
* krillin rc-proposed 315 (pay-service 15.10+15.04.20160324.1-0ubuntu1).
* arale rc-proposed 306 (pay-service 15.10+15.04.20160324.1-0ubuntu1).
* arale rc-proposed 262 (pay-service 15.10+15.04.20160114-0ubuntu1) (oldest rc-prop image on our servers).
* krillin rc 39 (OTA 8.5) (pay-service 2.0.0+15.04.20151103-0ubuntu1)
* krillin stable 27 (OTA 8) (pay-service 2.0.0+15.04.20151103-0ubuntu1)

I don't see the issue in:
* krillin stable 26 (OTA 7) (pay-service 2.0.0+15.04.20150914-0ubuntu1)
* krillin stable 24 (OTA 5) (pay-service 2.0.0+15.04.20150706-0ubuntu1)

BTW, this is really easy to check for. Flash an image, go to the app store, tap a paid app (I've been using "Cut the Rope" since it's on the front page today), tap the $2.99 button. Watch 'top' in a shell at the same time, to see if pay-service jumps up to 99% CPU. No need to even try to log in; it's sufficient to merely bring up the login UI.

[Víctor R. Ruiz (vrruiz)]

Thanks for confirming and investigate it, Selene!

[Launchpad Janitor (janitor)]

This bug was fixed in the package pay-service - 15.10+16.10.20160520-0ubuntu1

---------------
pay-service (15.10+16.10.20160520-0ubuntu1) yakkety; urgency=medium

  [ CI Train Bot ]
  * Resync trunk.

  [ Rodney Dawes ]
  * Add pep8 and pyflakes3 test rules. Clean up the warnings from pep8
    and pyflakes. (LP: #1421343)
  * Get rid of the glib usage entirely as we don't need it any more.
    Also remove the vendorized glib bindings. (LP: #1580195)
  * Use the ual API to get the icon path for the app for in-app
    purchases. (LP: #1582396)

  [ Timo Jyrinki ]
  * Stop depending on transitional packages. (LP: #1583079) Run wrap-
    and-sort -a -t on the packaging. (LP: #1583079)

 -- Rodney Dawes <email address hidden> Fri, 20 May 2016 14:27:32 +0000