RFR(M): 8194490: [JVMCI] Move `iterateFrames` to C++

[Vladimir Kozlov]

Thank you, Gilles

I looked on logs of timeouted testing and there were no failing tests 
until they timeout. So it should be fine.

Thanks,
Vladimir

On 3/6/18 8:23 AM, Gilles Duboscq wrote:
> I also re-generated a webrev that will apply cleanly:
> http://cr.openjdk.java.net/~gdub/webrev-8194490.2/
> 
> On 06/03/18 17:22, Gilles Duboscq wrote:
>> Hi,
>>
>> I re-ran the tests:
>> http://java.se.oracle.com:10065/mdash/jobs/gmdubosc-8194490-20180305-1320-13250
>> There are 2 timeouts (flaky test?)
>>
>> Tom, Doug, could either of you push this?
>>
>>   Gilles
>>
>> On 02/03/18 19:26, Vladimir Kozlov wrote:
>>> On 3/2/18 3:34 AM, Gilles Duboscq wrote:
>>>> Hi Vladimir,
>>>>
>>>> Sorry about that, somehow i never saw your first message.
>>>> Tom and Doug reviewed the JDK8 version internally.
>>>>
>>>> Beside the copyright year change of `src/hotspot/share/jvmci/jvmciCompilerToVM.cpp` everything still applies cleanly.
>>>> Should i consider this reviewed?
>>>
>>> Yes.
>>>
>>>> I guess i should re-run the tests since it's been a while.
>>>
>>> Yes, please update to latest jdk/hs sources and run testing again.
>>>
>>> Thanks,
>>> Vladimir
>>>
>>>>
>>>>    Gilles
>>>>
>>>> On 01/03/18 23:58, Vladimir Kozlov wrote:
>>>>> Hi Gilles,
>>>>>
>>>>> What happened to this fix?
>>>>>
>>>>> Testing all passed but it was not pushed.
>>>>>
>>>>> Thanks,
>>>>> Vladimir
>>>>>
>>>>> On 2/1/18 5:21 PM, Vladimir Kozlov wrote:
>>>>>> Thank you, Gilles
>>>>>>
>>>>>> Seems fine to me. Who reviewed it in Labs?
>>>>>>
>>>>>> And thank you for running testing.
>>>>>>
>>>>>> Vladimir
>>>>>>
>>>>>> On 1/22/18 6:58 AM, Gilles Duboscq wrote:
>>>>>>> Hi,
>>>>>>>
>>>>>>> Please review the following fix for `HotSpotStackIntrospection.iterateFrames`.
>>>>>>> It moves the iteration code from Java to C++: this helps with an issue that would arise if the nmethod containing the `iterateFrames` hits and uncommon trap during iteration. IT would change the layout of the top frames which would confuse the stack walking logic. Having this loop in C++ ensure there can be no uncommon trap.
>>>>>>>
>>>>>>> Webrev: http://cr.openjdk.java.net/~gdub/webrev-8194490/
>>>>>>> Issue: https://bugs.openjdk.java.net/browse/JDK-8194490
>>>>>>> Testing: hs-tier1,hs-tier2,hs-precheckin-comp
>>>>>>>
>>>>>>> It's bit unfortunate that we have tests for implementation details of JVMCI (i.e., tests for CompilerToVM) instead of tests for the actual API.
>>>>>>>
>>>>>>> Thanks,
>>>>>>>     Gilles
>>>>>>>