RFR JDK-8207197: [lworld] VarHandle array support for value types

[David Simms]

Looks good, ship it...


On 17/07/2018 7:33 p.m., mandy chung wrote:
> On 7/17/18 4:18 AM, David Simms wrote:
>>
>> Looks good, some minor suggestions (don't need follow up RFR)...
>>
>>
>> unsafe.cpp:315 :324 :360 :369
>>
>>      Suggest moving the "index" calculation into a new method in 
>> valueArrayKlass.hpp so any size related calculations are encapsulated 
>> in the same place. ("jint ValueArrayKlass::index_at_offset(jlong)" ?)
>
> The index calculation here is for assert and logging which is
> temporary to aid troubleshooting.  I don't see the need for
> ValueArrayKlass::index_at_offset and I would leave it as is.
> If we add it, it should probably detect invalid offset where
> possible and return -1.
>
> I move the assert and logging code in its function.
>
>> unsafe.cpp:319 :364
>>
>>      Add a final condition "else { ShouldNotReachHere(); }" in the 
>> ASSERT block, just in case
>
> Good suggestion.  I added that.
>
>> ArrayElementVarHandleTest.java
>>
>>      Run this tests with array flattening explicitly disabled via 
>> "-XX:-ValueArrayFlatten", and explicitly enabled 
>> "-XX:+ValueArrayFlatten" (i.e. 2 jteg @run lines)
>
> Thanks for the flag.  I added Unsafe::isFlattenedArray to detect
> if an array is flattened. We will revisit the Unsafe API after LW1.
>
> Webrev
> http://cr.openjdk.java.net/~mchung/valhalla/webrevs/8207197/webrev.01/
>
> Mandy
>