RFR(S): 8161379: @CallerSensitive methods should be forcefully inlined to get Reflection.getCallerClass optimization

[Claes Redestad]

On 2016-07-16 04:17, Christian Thalinger wrote:
> Why are you not setting the _force_inline bit on @CallerSensitive?  It would be less intrusive and more global so other compilers would pick it up as well.

We figured having ability to distinguish between reasons for why we're
force inlining could come in handy, but since the behavior would be the
same I'd be happy to simplify this if that'll make things easier for
other compilers.

Thanks!

/Claes

>
>> On Jul 15, 2016, at 2:12 PM, Claes Redestad <claes.redestad at oracle.com> wrote:
>>
>> Hi,
>>
>> Aleksey and I would like to contribute this patch which change the
>> inlining policy to treat @CallerSensitive as it would
>> @ForceSensitive.
>>
>> Bug: https://bugs.openjdk.java.net/browse/JDK-8161379
>> Webrev: http://cr.openjdk.java.net/~redestad/8161379/webrev.01/
>>
>> The issue is that the JNI call behind Reflection.getCallerClass() is
>> very expensive compared to the C2 intrinsic. This shows up in various
>> microbenchmarks stress-testing reflection, method handle lookup etc,
>> and can be linked to a number of intermittent regressions we see appear
>> in various benchmarks.
>>
>> See the bug for more information.
>>
>> Testing: JPRT -testset hotspot, RBT hotspot-nightly-compiler
>>
>> Thanks!
>>
>> /Claes
>