The good news is that Firefox 3, one of the best web browsers available, is set to release version 3 in a few days.
The weird news is that it’s shipping with Bug 183689 fully intact. Under mysterious (or at least elusive) circumstances, Firefox fails to close a file that the user uploads to a web site. The file is locked and unusable until Firefox is restarted.
This has the ring of familiarity. Any user of Firefox 2.x who has lots of extensions installed will have noticed that it tends to get more and more sluggish over time. A quick look at the process will reveal that memory consumption continuously rises until the best thing to do is restart it.
That’s not really a problem that the Firefox developers had a lot of control over. If an extension is leaking memory, there’s not much the core can do to stop it. In fact this is one of the major improvements in Firefox 3. A new, sophisticated memory manager now finds a lot of these unreferenced data structures and cleans them up. On my system, the memory footprint for Firefox 3 is nearly 200Mib smaller at start up, and if it grows, it doesn’t grow very fast. That alone is reason to upgrade on June 17, 2008 – Firefox Download Day.
The point of this digression is that I’ve become used to Firefox losing track of resources. But losing a file handle? Really. Can that be too hard to find? Apparently the answer is “yes”, since Bug 183689 has been open since December, 2002! There are some good reasons why the browser needs to keep track of the file, for example if you refresh the resulting page, the file is part of the Post data that needs to be re-sent.
But eliminating memory leaks is hard, and it’s easy to just rely on increasingly sophisticated garbage collection tools instead of finding the cause. Unfortunately, a garbage collector has no way of knowing that something it’s cleaning up represents an open file, so the memory leak is fixed, but the file handle leak remains.
Five-plus years is far too long for a major bug to remain open, even for an open source project. But don’t go updating that bug! Despite the fact that there’s no explanation that the issue is independent of the user’s specific circumstances, any provision of additional information will be considered spam by Jonas Sicking, the fellow who has been assigned the bug. Considering that the bug seems difficult to reproduce, the contradiction is obvious. One would think that more examples might lead to the discovery of a pattern, but that seems to not be the case as far as Mr. Sicking is concerned.
Hopefully he was just feeling a little stressed with a major release coming up so quickly, and his comment will be clarified or withdrawn. If not, I’m guessing this one is going to remain open for quite some time to come.
[Note: it has since been determined that an extension, LiveHTTPHeaders, is the culprit for this bug. My “duh” is withdrawn. My disdain for Mr. Sickling’s response remains unchanged, however.]