RFR (XS): 8022595: JSR292: deadlock during class loading of MethodHandles, MethodHandleImpl & MethodHandleNatives

[Vladimir Ivanov]

Yes, the test fails pretty reliably w/o the fix.

Best regards,
Vladimir Ivanov

On 8/20/13 10:23 PM, Vladimir Kozlov wrote:
> On 8/20/13 11:16 AM, Vladimir Ivanov wrote:
>> Vladimir,
>>
>> Thanks for the review.
>>
>> I specified /othervm, since I want to provoke a deadlock during JSR292
>> core classes initialization. If the classes are already initialized, the
>> test is meaningless.
>
> Okay. Did you reproduce the failure with VM without fix and this test?
>
> Thanks,
> Vladimir
>
>>
>> Best regards,
>> Vladimir Ivanov
>>
>> On 8/20/13 10:00 PM, Vladimir Kozlov wrote:
>>> Looks fine to me.
>>>
>>> You don't need /othervm in the test if you don't use any flags.
>>>
>>> Thanks,
>>> Vladimir
>>>
>>> On 8/20/13 10:05 AM, Vladimir Ivanov wrote:
>>>> http://cr.openjdk.java.net/~vlivanov/8022595/webrev.01/
>>>> 201 lines changed: 201 ins; 0 del; 0 mod;
>>>>
>>>> Some classes in j.l.invoke have circular dependencies between them
>>>> which
>>>> leads to deadlocks during class initialization when multiple threads
>>>> exercise JSR292 functionality.
>>>>
>>>> JSR292 core classes are among "well-known" classes to VM and they are
>>>> preloaded during VM startup (see
>>>> SystemDictionary::initialize_preloaded_classes). However, it doesn't
>>>> force preloaded classes to be initialized (doesn't execute static
>>>> initializers). Thus, these classes should be explicitly pre-initialized
>>>> in order to avoid deadlocks.
>>>>
>>>> Based on my observations of possible deadlock scenarios, I chose 3
>>>> classes to pre-initialize:
>>>>      - MethodHandle
>>>>      - MemberName
>>>>      - MethodHandleNatives
>>>>
>>>> I placed the code right after compilers initialization because during
>>>> method resolution for signature polymorphic intrinsics, compilation
>>>> tasks are issued (see SystemDictionary::find_method_handle_intrinsic
>>>> for
>>>> details) and they are missed if compiler subsystem isn't ready yet.
>>>>
>>>> Testing: failing test, regression test, JPRT, jdk/test/j/l/invoke,
>>>> vm.mlvm.testlist, octane.
>>>>
>>>> Thanks!
>>>>
>>>> Best regards,
>>>> Vladimir Ivanov