365983 - after cycle collector has landed Leak Monitor alerts about leaks in Gmail

Status: RESOLVED WONTFIX

(Core :: General, defect)

Description

[Peter van der Woude [:Peter6]]

Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9a2pre) Gecko/20070104 Minefield/3.0a2pre ID:2007010414 [cairo]

after Bug 333078 ,cycle collector, has landed Leak Monitor alerts about leaks in Gmail (not visable before)

repro:

open Gmail
reload Gmail

Leaks in window 0x3c602a0:
[+] [leaked object] (4bc1420, https://mail.google.com/mail/?view=page&name=js&ver=10f2r6op2nyf6, 70-70) = [Function]
 [ ] prototype (1a594c0) = [Object]
[+] [leaked object] (4bc1520, https://mail.google.com/mail/?view=page&name=js&ver=10f2r6op2nyf6, 70-70) = [Function]
 [ ] prototype (1a59480) = [Object]
[+] [leaked object] (4bc14a0, https://mail.google.com/mail/?view=page&name=js&ver=10f2r6op2nyf6, 70-70) = [Function]
 [ ] prototype (1a59460) = [Object]
[+] [leaked object] (4bc1380, https://mail.google.com/mail/?view=page&name=js&ver=10f2r6op2nyf6, 70-70) = [Function]
 [ ] prototype (1a593e0) = [Object]
[+] [leaked object] (4bc12c0, https://mail.google.com/mail/?view=page&name=js&ver=10f2r6op2nyf6, 70-70) = [Function]
 [ ] prototype (1a593c0) = [Object]

and

Leaks in window 0x3dcd2c0:
[+] [leaked object] (42608c0, https://mail.google.com/mail/?view=page&name=js&ver=10f2r6op2nyf6, 70-70) = [Function]
 [ ] prototype (21e9ba0) = [Object]
[+] [leaked object] (42606e0, https://mail.google.com/mail/?view=page&name=js&ver=10f2r6op2nyf6, 70-70) = [Function]
 [ ] prototype (21e9b60) = [Object]
[+] [leaked object] (4260820, https://mail.google.com/mail/?view=page&name=js&ver=10f2r6op2nyf6, 70-70) = [Function]
 [ ] prototype (21e9b20) = [Object]
[+] [leaked object] (4260780, https://mail.google.com/mail/?view=page&name=js&ver=10f2r6op2nyf6, 70-70) = [Function]
 [ ] prototype (21e9b00) = [Object]
[+] [leaked object] (25907a0, https://mail.google.com/mail/?view=page&name=js&ver=10f2r6op2nyf6, 70-70) = [Function]
 [ ] prototype (21e9ae0) = [Object]

Comment 1

[David Baron :dbaron: (⌚️UTC-4, no longer working on Mozilla)]

Leak monitor isn't going to work correctly given the cycle collector landing.

I need a notification that a cycle collection has happened to tell that I should look for leaks.  I currently do this after a JS GC, but that's no longer sufficient.

(That said, there's no guarantee that there aren't real leaks too.)

Comment 2

[Dão Gottwald [:dao]]

(In reply to comment #1)
> (That said, there's no guarantee that there aren't real leaks too.)

So this is "potentially" blocking bug 333078, I guess.

Comment 3

[Steve England [:stevee]]

David, should the leak-gauge.pl script still work ok?

Comment 4

[David Baron :dbaron: (⌚️UTC-4, no longer working on Mozilla)]

(In reply to comment #3)
> David, should the leak-gauge.pl script still work ok?

Yes.

Comment 5

[Graydon Hoare :graydon]

I hate to be such a thorn in your side, but I suspect leak-gauge.pl will be misreporting as well; the XPCOM cycle collector does not perform any last-ditch collections during shutdown, so it's possible that leak-gauge.pl will report hard leaks for garbage cycles that were actually transient (buffered, awaiting collection) at shutdown.

Again, this might be fixable in several ways, but most likely in the short term you'll see a bunch of new "leaks" that may or may not be real. 

You'll also see an increase in the average resident set of the process, since transient garbage cycles take up real space until they're collected.

Comment 6

[Steve England [:stevee]]

OK thanks Graydon. I've just tried the leak-gauge.pl on a new profile with Mozilla/5.0 (Windows; U; Windows NT 5.0; en-US; rv:1.9a2pre) Gecko/20070105 Minefield/3.0a2pre ID:2007010509 [cairo] and it does indeed report a whole lot of leakage when simply loading firefox, closing firefox and analysing the log.

Comment 7

[Nickolay_Ponomarev]

Was there a bug filed for the issue in comment 5/6 (not cleaning up on shutdown thus breaking leak-gauge)?

Comment 8

[Graydon Hoare :graydon]

(In reply to comment #7)
> Was there a bug filed for the issue in comment 5/6 (not cleaning up on shutdown
> thus breaking leak-gauge)?
> 

There is now: Bug 366578.

Comment 9

[Olli Pettay [:smaug][[e-mail]]]

Is this still valid? Using XPCOM_MEM_LEAK_LOG I couldn't see
any window or document leaks after logging in to gmail and reloading it.

Comment 10

[Peter van der Woude [:Peter6]]

Yes, with Leak Monitor 0.3.6 there are still warnings when you open gmail

Comment 11

[Peter van der Woude [:Peter6]]

Leaks in window 0x31df0a0:
[+] [leaked object] (22ab260, https://mail.google.com/mail/?view=page&name=js&ver=1kudxq6lor5wp, 71-71) = [Function]
 [ ] prototype (214a860) = [Object]
[+] [leaked object] (4ea7980, https://mail.google.com/mail/?view=page&name=js&ver=1kudxq6lor5wp, 71-71) = [Function]
 [ ] prototype (214a4e0) = [Object]
[+] [leaked object] (4ea7900, https://mail.google.com/mail/?view=page&name=js&ver=1kudxq6lor5wp, 71-71) = [Function]
 [ ] prototype (214a0a0) = [Object]
[+] [leaked object] (3bc35e0, https://mail.google.com/mail/?view=page&name=js&ver=1kudxq6lor5wp, 71-71) = [Function]
 [ ] prototype (21aa4e0) = [Object]
[+] [leaked object] (3bc3520, https://mail.google.com/mail/?view=page&name=js&ver=1kudxq6lor5wp, 71-71) = [Function]
 [ ] prototype (21aa3a0) = [Object]

Comment 12

[Damon Sicore (:damons)]

We're not going to block a release on leak monitor, right?  -'ing.  Please renom if you disagree.

Comment 13

[David Baron :dbaron: (⌚️UTC-4, no longer working on Mozilla)]

Leak Monitor is no longer maintained.