RFR 8199868: Support JNI critical functions in object pinning API

[Roman Kennke]

Am 09.07.2018 um 15:57 schrieb Andrew Haley:
> On 06/15/2018 12:55 PM, Zhengyu Gu wrote:
>> Ping!!!! anyone? please!
> 
> How did you test this?  Do you have code that exercises the interface?
> If so, please put it on cr.openjdk.
> 

We have tests in Shenandoah. We would upstream it, but it requires a GC
that supports pinning. AFAIK, ZGC devs *intend* to support pinning, and
for G1 it should be easy as well. But it's not there yet.

This is the test:
http://hg.openjdk.java.net/shenandoah/jdk/file/266e6a543eaa/test/hotspot/jtreg/gc/shenandoah/CriticalNativeStress.java

Zhengyu: do you see a way to test this even without a supporting GC?

Roman