RFR: 8205694: AArch64: Add test to validate volatile load, store and CAS code generation

[Dmitrij Pochepko]

27.06.2018 19:03, Andrew Dinn пишет:
> On 27/06/18 15:41, Dmitrij Pochepko wrote:
>> On 27.06.2018 16:05, Andrew Dinn wrote:
>>> On 27/06/18 13:29, Dmitrij Pochepko wrote:
>>>> On 27.06.2018 13:54, Andrew Dinn wrote:
>>>>> On 26/06/18 19:33, Dmitrij Pochepko wrote:
>>>>>> 1. Most tests which spawn other precesses for testing purposes are
>>>>>> launched as "@run driver ..." for optimization reasons.
>>>>> I'm using the Process API so I can retrieve and analyze the output
>>>>> written to the spawned JVM's stdout. Is it possible to do that using
>>>>> "@run driver"?
>>>> yes
>>> Well, that's good to know ;-) but still could you explain how or point
>>> at an example?
>> it's the same as for @run main. External vm options are stored by jtreg
>> in several vm properties: test.vm.opts and test.java.opts (for
>> -vmoptions and -javaoptions respectively), so, process tools use it in
>> case you call createJavaProcessBuilder with first parameter == true.
>> Here is an example how this could be done:
>> gc/arguments/TestUseNUMAInterleaving.java
>
> I'm really not sure what you are recommending here. Are you simply
> saying that I need to change the @run directives so that they say
>
>    @run driver compiler.c2.aarch64.TestVolatiles
>
> instead of
>
>    @run main compiler.c2.aarch64.TestVolatiles
>
> If so then I can easily do that but I would really like to understand
> why that is better -- as you say -- 'for optimization reasons'.
>
> Could you clarify if that is all you are suggesting and if so why it
> improves the situation?
Yes. It is exactly what I'm suggesting. @run driver is a specifical 
subform of @run main, which always run in same vm as jtreg, without 
spawning additional java process.

Official jtreg guideline also says about 
driver(http://openjdk.java.net/jtreg/tag-spec.html): "Invoke the main 
method of the specified class, passing any arguments after the class 
name. Although superficially similar to @run main, this is for use when 
it is desirable to perform additional setup or configuration before 
running the class containing the actual test code, possibly in a child VM."
>
> If, instead, you are suggesting I do something more (or something else)
> then can you give a precise and clear explanation of what I would need
> to change and why? For now it would be best to base that on the original
> webrev just to avoid any further confusion.
>
> regards,
>
>
> Andrew Dinn
> -----------
> Senior Principal Software Engineer
> Red Hat UK Ltd
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