RFR: 8233343: Deprecate -XX:+CriticalJNINatives flag which implements Java… [v2]

[Zhengyu Gu]

On Wed, 21 Oct 2020 11:59:26 GMT, Coleen Phillimore <coleenp at openjdk.org> wrote:

>> This change deprecates the -XX:+CriticalJNINatives flag and removes the develop flag -XX:+StressCriticalJNINatives.  See CSR for more details.
>> 
>> This change also removes the lazy GC lock in the critical native transition, and runs the critical native function as thread_in_Java.  I add a safepoint check at the end of the native function and transition to native and poll again for the safepoint after the function if a safepoint is requested.
>> 
>> Tested with tier 1-6 (we have a few tests that use this).  And built on linux-x86-open,linux-s390x-open,linux-arm32-debug,linux-ppc64le-debug.
>
> Coleen Phillimore has updated the pull request incrementally with two additional commits since the last revision:
> 
>  - Fixed test to run on other platforms, fixed copyrights, fixed ppc code.
>  - Remove pin/unpin object code.

Marked as reviewed by zgu (Reviewer).

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PR: https://git.openjdk.java.net/jdk/pull/764