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TEST(MinidumpWriterTest, MinidumpSizeLimit) is flaky #510

Closed GoogleCodeExporter closed 9 years ago

GoogleCodeExporter commented 9 years ago 
What steps will reproduce the problem?
1. Imported google-breakpad into google3 and tried to run the unittests. 
2. built unittests
3. Run n

What is the expected output? What do you see instead?

All unittests must succeed.

Please use labels and text to provide additional information.

http://code.google.com/p/google-breakpad/source/detail?r=1082

Original issue reported on code.google.com by ivan.penkov on 11 Dec 2012 at 12:29

GoogleCodeExporter commented 9 years ago 
I clicked enter too fast, so I was unable to enter all necessary information.

Basically, the estimation for an average stack size (of 8 KB) seems wrong.  I 
added some logging and it appears that when compiling and running this in 
Google most of the stacks sizes are actually KB. 

Changing the following constant from 8 to 12 KB seems to fix the issue, however 
I'm not confident that this test can be very reliable in the long term in its 
current form (average stack size differs based on tools).

  static const unsigned kLimitAverageThreadStackLength = 8 * 1024;

Thanks,
-Ivan

Original comment by ivan.penkov on 11 Dec 2012 at 12:41

GoogleCodeExporter commented 9 years ago 
Hmm.. which part of the test is failing?  Can you include the error message(s)?

That stack size just happened to be what I was seeing in the too-large 
minidumps, so it's fairly arbitrary.  At the same time, I didn't intend the 
unittest to depend on what the stack size actually turns out to be (e.g. it 
checks for only a 1KB decrease in per-thread stack size).

Original comment by mkr...@chromium.org on 11 Dec 2012 at 1:13

GoogleCodeExporter commented 9 years ago 
Here are actual assertions that were hit:

third_party/breakpad/src/client/linux/minidump_writer/minidump_writer_unittest.c
c:705: Failure
Expected: (st.st_size) < (normal_file_size), actual: 585664 vs 585664
Stack trace:
0x00416e26: (anonymous 
namespace)::MinidumpWriterTest_MinidumpSizeLimit_Test::TestBody() @ 
third_party/breakpad/src/client/linux/minidump_writer/minidump_writer_unittest.c
c:705
0x00490ae6: void 
testing::internal::HandleSehExceptionsInMethodIfSupported<testing::Test, 
void>(testing::Test*, void (testing::Test::*)(), char const*) @ 
third_party/gtest/src/gtest.cc:2086
0x0048dca6: void 
testing::internal::HandleExceptionsInMethodIfSupported<testing::Test, 
void>(testing::Test*, void (testing::Test::*)(), char const*) @ 
third_party/gtest/src/gtest.cc:2138
0x00482609: testing::Test::Run() @ third_party/gtest/src/gtest.cc:2158
0x00482bea: testing::TestInfo::Run() @ third_party/gtest/src/gtest.cc:2334
... gUnit internal frames ...
...
...
third_party/breakpad/src/client/linux/minidump_writer/minidump_writer_unittest.c
c:729: Failure
Expected: (total_limit_stack_size) < (total_normal_stack_size - 
min_expected_reduction), actual: 503808 vs 483328
Stack trace:
0x00417493: (anonymous 
namespace)::MinidumpWriterTest_MinidumpSizeLimit_Test::TestBody() @ 
third_party/breakpad/src/client/linux/minidump_writer/minidump_writer_unittest.c
c:729
0x00490ae6: void 
testing::internal::HandleSehExceptionsInMethodIfSupported<testing::Test, 
void>(testing::Test*, void (testing::Test::*)(), char const*) @ 
third_party/gtest/src/gtest.cc:2086
0x0048dca6: void 
testing::internal::HandleExceptionsInMethodIfSupported<testing::Test, 
void>(testing::Test*, void (testing::Test::*)(), char const*) @ 
third_party/gtest/src/gtest.cc:2138
0x00482609: testing::Test::Run() @ third_party/gtest/src/gtest.cc:2158
0x00482bea: testing::TestInfo::Run() @ third_party/gtest/src/gtest.cc:2334
... gUnit internal frames ...

I added some temporary logging which shows average stack size of 12 KB:
...
...
Actual stack lenght is: 32768
Actual stack lenght is: 12288
Actual stack lenght is: 12288
Actual stack lenght is: 12288
Actual stack lenght is: 12288
Actual stack lenght is: 12288
Actual stack lenght is: 12288
Actual stack lenght is: 12288
Actual stack lenght is: 12288
Actual stack lenght is: 12288
Actual stack lenght is: 12288
Actual stack lenght is: 12288
Actual stack lenght is: 12288
Actual stack lenght is: 12288
Actual stack lenght is: 12288
Actual stack lenght is: 12288
Actual stack lenght is: 12288
Actual stack lenght is: 12288
Actual stack lenght is: 12288
Actual stack lenght is: 12288
Actual stack lenght is: 12288
...
...

Original comment by ivan.penkov on 11 Dec 2012 at 7:07

GoogleCodeExporter commented 9 years ago 
At the same time when I build and run it, on an SVN client directly off of 
http://code.google.com/p/google-breakpad, I get an average stack size of 4 KB, 
so the particular tools used for building matter:

...
Actual  stack length is 4096
Actual  stack length is 4096
Actual  stack length is 4096
Actual  stack length is 4096
Actual  stack length is 4096
Actual  stack length is 4096
Actual  stack length is 4096
Actual  stack length is 4096
Actual  stack length is 4096
Actual  stack length is 4096
Actual  stack length is 4096
Actual  stack length is 4096
Actual  stack length is 4096
Actual  stack length is 4096
Actual  stack length is 4096
Actual  stack length is 4096
Actual  stack length is 4096
Actual  stack length is 4096
Actual  stack length is 4096
Actual  stack length is 4096
Actual  stack length is 4096
Actual  stack length is 4096
Actual  stack length is 8192
Actual  stack length is 4096
Actual  stack length is 4096
Actual  stack length is 4096
Actual  stack length is 4096
Actual  stack length is 4096
Actual  stack length is 4096
Actual  stack length is 4096
Actual  stack length is 4096
Actual  stack length is 4096
Actual  stack length is 4096
Actual  stack length is 4096
Actual  stack length is 4096
Actual  stack length is 4096
Actual  stack length is 4096
Actual  stack length is 4096
Actual  stack length is 4096
Actual  stack length is 4096
Actual  stack length is 4096
Actual  stack length is 4096
Actual  stack length is 4096
Actual  stack length is 4096
...

Original comment by ivan.penkov on 11 Dec 2012 at 7:30

GoogleCodeExporter commented 9 years ago 
It's actually a reverse effect.  The larger stack size is making it so the 
size-limiting logic doesn't kick in.  I.e. It's actually okay to have the 8KB 
estimate for a stack size, but the test has to be changed to work when the 
stack size is bigger.

I'll upload a change to adjust the unittest's size limit so it will kick in.

Worst case, if we have an issue like this again, it can be changed to something 
like 32KB -- which will always trigger the size-limiting code -- but I'm hoping 
it can be a little better than that in order to increase the effectiveness of 
the test.

Original comment by mkr...@chromium.org on 11 Dec 2012 at 10:56

GoogleCodeExporter commented 9 years ago 
Let me know when you are done with the adjustment and I can test it in google3.

Original comment by ivan.penkov on 11 Dec 2012 at 11:14

GoogleCodeExporter commented 9 years ago 
Thanks.  You can find the change in CL https://breakpad.appspot.com/504002/.

Original comment by mkr...@chromium.org on 11 Dec 2012 at 11:17

GoogleCodeExporter commented 9 years ago 
CL committed.

Original comment by mkr...@chromium.org on 12 Dec 2012 at 2:31

GoogleCodeExporter commented 9 years ago

Original comment by ivan.penkov on 12 Dec 2012 at 11:53

GoogleCodeExporter commented 9 years ago 
A similar failure is being hit by the the Chromium Android Tests (dbg) build 
bot.
Please follow up with https://code.google.com/p/chromium/issues/detail?id=305008

Original comment by msw@chromium.org on 8 Oct 2013 at 7:07

GoogleCodeExporter commented 9 years ago

Original comment by vapier@chromium.org on 23 Oct 2013 at 3:12