David Baron's weblog: June 2007

Accessibility and standards (01:17 -0700)

Henri Sivonen wrote a great message in the recent discussion on the HTML working group list about accessibility. He explained a lot of the things that have been bothering me about that discussion much better than I would have if I'd chimed in.

Memory use profiles (16:10 -0700)

I've done some memory use profiles over the past few days that may be of interest. If you see things in them where we shouldn't be using the amount of memory that they show, please file a bug.

I found it rather shocking that pango spends close to half a megabyte loading the gpos and gsub tables of a single font (since opening empty tabs means loading the bold font to display the tab labels), but Vlad tells me that Behdad has a plan (and maybe a patch?) to fix this.

Memory leak testing on trunk builds, round 2 (12:15 -0700)

My previous call for leak testing uncovered multiple reports of one common leak. Now that that's fixed, more testing is useful again.

I'd also note that Dave Townsend has incorporated the leak-gauge script into nightly tester tools, which provides a third way to run the script. (But, as with the HTML + JavaScript version, be careful not to overwrite the log you want to analyze when starting the browser.)

Memory leak testing needed on trunk builds (17:05 -0700)

Many of the leak regressions that resulted from the cycle collector landing have now been fixed, but the trunk still seems to be leaking more memory than it did six months ago. I've noticed this because I've been doing most of my browsing with leak logging, and looking at the resulting logs. However, I haven't had the time to simplify testcases for all the problems I'm seeing: that's sometimes a lot of work, and sometimes I can't figure out what I did on a page that would have caused it to leak (such that I see the leak again).

If you want Firefox 3 to leak less than Firefox 2, please help finding memory leaks. What's most useful right now is this:

1. Download the leak-gauge script (available in a perl version for those who have perl installed, or a slightly harder to use HTML + Javascript version for those who don't have perl).
2. Do your Web browsing using a Firefox trunk build with the environment variables set as described in the leak-gauge script, and then when you exit Firefox, run the leak-gauge script on the resulting log.
3. If you see leaks, figure out what caused them, and file good memory leak bugs in Bugzilla. (If you run into other bugs in the trunk builds, please file them too.)