Sometimes an activity will not start

[erikos]

With patches from #282 applied I do test 'sugar-emulator -s 72' and sometimes an activity will not start. Nothing in the logs besides:

1235985553.237079 DEBUG root: None launched in 0.004011 seconds.

I could not reproduce yet with 'sugar-emulator -s 100'. I did always erase the ~/.sugar/ before testing.

[erikos]

the launcher is flashing but the activity is not launched

[tomeu]

Maybe a dupe of #426?

[erikos]

Nope I actually still see this. And I just reproduced it (with SCALING 100) when checking #426. So I did start Terminal and restarted it again from the home view and closed it then. Then I started Write (it did not have an entry in the Journal yet) and I saw the pulsing launcher but no start - like described above.

[alsroot]

there is a race condition between ActivateActivity()[1] invoking from sugar-toolkit/src/sugar/activity/activityfactory.py:_launch_activity() and add_launcher()[2] invoking from sugar/src/jarabe/view/palettes.py:start_activate_cb():

- [2] creates new launcher window
- this window could be(still) not-registered before invoking [1]

attached patch adds workaround code(for 0.84 release only) - creating activity in any case(launcher window was registered or not)

[alsroot]

workaround fix

[tomeu]

Replying to alsroot:

there is a race condition between ActivateActivity()[1] invoking from sugar-toolkit/src/sugar/activity/activityfactory.py:_launch_activity() and add_launcher()[2] invoking from sugar/src/jarabe/view/palettes.py:start_activate_cb():

- [2] creates new launcher window
- this window could be(still) not-registered before invoking [1]

Thanks for the analysis, seems to be right.

Your patch fixes the race, but doesn't take into account switching to an existing instance. The one I'm attaching should work for that as well.

[tomeu]

r+'ed in #sugar by Simon and Aleksey.

Fixed by  http://git.sugarlabs.org/projects/sugar/repos/mainline/commits/a4dad1b0

Thanks a lot to Aleksey for tracking this one down.