By introducing the first indexedDB mochitest browser test in bug 861308, I found that indexedDB keeps mainthread objects alive until pending off main-thread work is complete. This may last a few milliseconds, though it totally confuses our leak detection, that runs as soon as the test completes. This is a case I found, but I can easily see it may happen in other cases, especially now that we move towards more multi-threaded components, it may even be cause of some intermittent reported leaks. I suggest when a leak is detected we "sleep" a small timeframe (I suggest 1s) and then we retry the leak checking. This is not a perfect solution (we can't detect easily work completion on other threads), but should improve the situation without increasing much the time since it acts only when a globalwindow leak is detected. I will try making the change and see how it behaves in the indexedDB case.

oh, well, looks like I must fix something in aboutHome.js, though should be part of bug 789348, I will do another try with just this patch.

Comment on attachment 739512 [details] [diff] [review] patch v1.0 Review of attachment 739512 [details] [diff] [review]: ----------------------------------------------------------------- Sounds reasonable to me as we're only waiting for a second when detecting a leak (which is the exception). Maybe we could also kick off a GC right before analyzing the CC graph again. smaug suggested doing this in another patch I was writing but I can't exactly remember why. Shouldn't hurt, though. Also, <3 fat arrow functions.

(In reply to Tim Taubert [:ttaubert] from comment #4) > Maybe we could also kick off a GC right > before analyzing the CC graph again. afaict the analyzer already runs 3 gc before analyzing, am I wrong?

(In reply to Marco Bonardo [:mak] from comment #5) > (In reply to Tim Taubert [:ttaubert] from comment #4) > > Maybe we could also kick off a GC right > > before analyzing the CC graph again. > > afaict the analyzer already runs 3 gc before analyzing, am I wrong? Right! Was just testing you, carry on :)