In last week’s downtime, Alice re-tried enabling TShutdown tests in production Talos, and this time it all went smoothly. This change is important for two reasons:

1) Fixes an intermittent Talos orange problem
Basically, each Talos test assumed that the previous suite had already ended and exited browser successfully. However, sometimes (usually Vista!), we found that closing a healthy browser took longer then expected. This would cause the next Talos suite to fail out because of the lingering process left by the previous talos suite.

This fix should greatly reduce intermittent oranges from Talos in mozilla-central, mozilla-1.9.1 and tracemonkey. In the few days since its been enabled, things look much better already!

2) Users care about shutdown times
Just like we measure startup time, it feels right to measure shutdown time. It was never measured before, but once the idea came up, this felt like a good thing to measure. There are also some edge cases where users exit-and-quickly-restart firefox, which can become unhappy if the browser process is still slowly closing down.

The curious can find more details in Alice’s blogpost here.