[9] RFR(S): 8065740: compiler/codecache/OverflowCodeCacheTest.java fails with SIGSEGV

[Igor Ignatyev]

On 11/26/2014 09:48 AM, Tobias Hartmann wrote:
> Albert, Igor, thanks for the review.
>
> On 25.11.2014 16:22, Igor Ignatyev wrote:
>> Hi Tobias,
>>
>> isn't it another manifestation of JDK-8064669[1,2] ?
>
> Yes, I missed that. I'll close the bug as a duplicate.
>
> Since you didn't push yet, could you add the two code cleanups (typo in
> whitebox.cpp and removal of comment in sweeper.cpp) to your change?
sure.
>
> Thanks,
> Tobias
>
>>
>> [1] https://jbs.oracle.com/bugs/browse/JDK-8064669
>> [2]
>> http://mail.openjdk.java.net/pipermail/hotspot-compiler-dev/2014-November/016283.html
>>
>>
>> Igor
>>
>> On 11/25/2014 05:58 PM, Tobias Hartmann wrote:
>>> Hi,
>>>
>>> please review the following patch.
>>>
>>> Bug: https://bugs.openjdk.java.net/browse/JDK-8065740
>>> Webrev: http://cr.openjdk.java.net/~thartmann/8065740/webrev.00/
>>>
>>> Problem:
>>> The test allocates CodeBlobs in the code cache by using the Whitebox API method
>>> 'WhiteBox::allocate_code_blob' introduced by JDK-8059624. The VM crashes while
>>> sweeping because it encounters an allocated but uninitialized CodeBlob in the
>>> code cache (crash happens in NMethodIterator::next_method because we call
>>> '_code_blob->is_nmethod()' on an uninitialised CodeBlob).
>>> The problem is that 'WhiteBox::allocate_code_blob' gives up the CodeCache_lock
>>> before initializing the CodeBlob. This allows the sweeper thread to encounter a
>>> yet uninitialized CodeBlob while iterating over the code cache.
>>>
>>> Solution:
>>> I moved the initialization of the CodeBlob into the scope of the CodeCache_lock.
>>> I also fixed some typos and removed a comment that became meaningless with
>>> JDK-8046809.
>>>
>>> Testing:
>>> - Failing testcase
>>> - JPRT
>>>
>>> Thanks,
>>> Tobias
>>>