RLk: 0B (01:14 -0700)

I've been working on memory leaks in Mozilla for a while. Back in 2000, when I first got interested in fixing memory leaks (at least partly thanks to reading some bugs filed by Bruce Mitchener), one of the things I focused on was trying to fix the leak number that showed up on tinderbox. The first bug in that quest was a pretty interesting one, and a number of the other early bugs were real leaks that affected users (including a whole bunch related to form controls). The leak numbers on tinderbox got pretty low, and most of the number shown was due to shutdown leaks: leaks where we allocated an object that was supposed to exist for the lifetime of the application, but then we didn't free it at shutdown. Not a real problem, and only harmful in that it cluttered up the list of objects that weren't freed at shutdown and made it slightly harder to find real leaks.

So I eventually moved on to working on reducing measures of memory leaks that were more relevant to problems that users experience (the amount of memory Firefox uses being large and increasing over time). I eventually added a better leak test to tinderbox and renamed the old one (which only measured leaks of XPCOM objects and certain other logged objects) to RLk. (That improved the measurement of leaks during the test, but we still really need a leak test that exercises more code.)

But recently, sayrer revived an old patch to make XPConnect shut down more cleanly and stop giving false leak reports anytime somebody did anything interesting in a JS component, and bsmedberg fixed some leaks very near main, and the RLk number dropped precipitously close to zero. I debugged the last issue last week (amazingly enough, it was not a shutdown leak, although the only XPCOM object leaked was a singleton). I checked that patch in just now, so now, for the first time, we have a tinderbox showing RLk: 0B for reasons other than the leak test being broken. It's not very important compared to the other memory leak work going on, but it is rather satisfying.