RFR: 8264774: Implementation of Foreign Function and Memory API (Incubator) [v16]

[Vladimir Ivanov]

On Mon, 10 May 2021 20:43:20 GMT, Maurizio Cimadamore <mcimadamore at openjdk.org> wrote:

>> This PR contains the API and implementation changes for JEP-412 [1]. A more detailed description of such changes, to avoid repetitions during the review process, is included as a separate comment.
>> 
>> [1] - https://openjdk.java.net/jeps/412
>
> Maurizio Cimadamore has updated the pull request incrementally with one additional commit since the last revision:
> 
>   * Remove unused imports
>   * Fix broken javadoc after removal of @throws clauses
>   * Remove other `@CallerSensitive` annotations from `AbstractCLinker`

Overall, hotspot and java.lang.invoke changes look good.

One comment though on naming: there are multiple references to Panama in the code. Moreover, it is used inconsistently (`is_panama_entry_frame()` vs `EntryBlob` vs `OptimizedUpcallStub`). 
I suggest to get rid of any references to Panama and use `optimized`uniformly where appropriate (`is_optimized_entry_frame()`, `OptimizedEntryBlob`, `OptimizedUpcallStub`).

Some minor comments follow.

src/hotspot/share/prims/universalUpcallHandler.cpp line 122:

> 120: JNI_END
> 121: 
> 122: JVM_ENTRY(jlong, PUH_AllocateOptimzedUpcallStub(JNIEnv *env, jclass unused, jobject mh, jobject abi, jobject conv))

Typo: `PUH_AllocateOptimzedUpcallStub` -> `PUH_AllocateOptimizedUpcallStub`.

src/hotspot/share/prims/universalUpcallHandler.cpp line 137:

> 135: JVM_END
> 136: 
> 137: JVM_ENTRY(jboolean, PUH_SupportsOptimzedUpcalls(JNIEnv *env, jclass unused))

Typo: `Optimzed` -> `Optimized`

src/hotspot/share/runtime/sharedRuntime.hpp line 465:

> 463:   static void restore_native_result(MacroAssembler *_masm, BasicType ret_type, int frame_slots);
> 464: 
> 465:   static void   move32_64(MacroAssembler* masm, VMRegPair src, VMRegPair dst);

Please, file an RFE to move these declarations to `MacroAssembler`.

-------------

Marked as reviewed by vlivanov (Reviewer).

PR: https://git.openjdk.java.net/jdk/pull/3699