733374 - WARNING: The two measurements of 'explicit' memory usage don't match

Status: RESOLVED FIXED

(Core :: XPCOM, defect)

Description

[Mark Banner (:standard8)]

I've been hitting this on almost every Thunderbird run recently.

WARNING: The two measurements of 'explicit' memory usage don't match (23789568 vs 24051712): file /Users/moztest/comm/reviewcc/src/mozilla/xpcom/base/nsMemoryReporterManager.cpp, line 832

STR:

1) Build Thunderbird in debug mode
2) Run Thunderbird
3) Wait

Actual results: get a warning
Expected results: no warning.

I'm running Thunderbird using a clang build on 10.6.

Comment 1

[Nicholas Nethercote [inactive]]

I fixed this yesterday in a follow-up patch, see bug 729403 comment 8.  Please reopen if you still see it in updated builds.  Thanks!

Comment 2

[Jesse Ruderman]

Interesting that a heap-vs-nonheap mistakes triggers this warning, but doesn't trigger any assertions.  Are there (sound) assertions we could add to catch that kind of problem more quickly?

Comment 3

[Nicholas Nethercote [inactive]]

(In reply to Jesse Ruderman from comment #2)
> Interesting that a heap-vs-nonheap mistakes triggers this warning, but
> doesn't trigger any assertions.  Are there (sound) assertions we could add
> to catch that kind of problem more quickly?

When everything is ok the test fails occasionally.  And when memory reporters have defects (like mixing up HEAP and NONHEAP) it fails every time.

I guess I could add a counter, and if the first N tests all fail, then trigger an assertion?

Comment 4

[Nicholas Nethercote [inactive]]

Patch 3 in bug 859657 will remove this warning.

Comment 5

[Nicholas Nethercote [inactive]]

> Patch 3 in bug 859657 will remove this warning.

It just landed.