RFR: 8275800: Redefinition leaks MethodData::_extra_data_lock [v2]

[Serguei Spitsyn]

On Mon, 25 Oct 2021 22:49:39 GMT, Coleen Phillimore <coleenp at openjdk.org> wrote:

>> The Mutex destructor isn't called for the MDO lock.  We found this leak with crashes for the patch to print all mutex locks on error, which is now withdrawn.  It was easily reproduced with that patch.  It is not easily reproduced otherwise.
>> I tested this change with that patch though and it passes tier1-6,
>
> Coleen Phillimore has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Add parameter to release_C_heap_structures.

Coleen,
It looks good to me.
Thanks,
Serguei

src/hotspot/share/oops/instanceKlass.cpp line 2693:

> 2691:   Klass::release_C_heap_structures();
> 2692:   if (release_constant_pool) {
> 2693:     constants()->release_C_heap_structures();

Just wanted to note that the order of de-allocations has been changed with this fix. It should not be important though. To be fully safe this deallocation can be moved to the end of `release_C_heap_structures`.

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Marked as reviewed by sspitsyn (Reviewer).

PR: https://git.openjdk.java.net/jdk/pull/6105