RFR: 8347408: Create an internal method handle adapter for system calls with errno [v3]

[Shaojin Wen]

On Tue, 6 May 2025 12:30:01 GMT, Per Minborg <pminborg at openjdk.org> wrote:

>> src/java.base/share/classes/jdk/internal/foreign/CaptureStateUtil.java line 390:
>> 
>>> 388:                 return MhUtil.findVirtual(LOOKUP, Arena.class, "close",
>>> 389:                         MethodType.methodType(void.class));
>>> 390:         }
>> 
>> Suggestion:
>> 
>>         return switch (index) {
>>             case NON_NEGATIVE_INT -> MhUtil.findStatic(LOOKUP, "nonNegative",
>>                     MethodType.methodType(boolean.class, int.class));
>>             case SUCCESS_INT -> MhUtil.findStatic(LOOKUP, "success",
>>                     MethodType.methodType(int.class, int.class, MemorySegment.class));
>>             case ERROR_INT -> MhUtil.findStatic(LOOKUP, "error",
>>                     MethodType.methodType(int.class, MethodHandle.class, int.class, MemorySegment.class));
>>             case NON_NEGATIVE_LONG -> MhUtil.findStatic(LOOKUP, "nonNegative",
>>                     MethodType.methodType(boolean.class, long.class));
>>             case SUCCESS_LONG -> MhUtil.findStatic(LOOKUP, "success",
>>                     MethodType.methodType(long.class, long.class, MemorySegment.class));
>>             case ERROR_LONG -> MhUtil.findStatic(LOOKUP, "error",
>>                     MethodType.methodType(long.class, MethodHandle.class, long.class, MemorySegment.class));
>>             case ACQUIRE_ARENA -> MhUtil.findStatic(LOOKUP, "acquireArena",
>>                     MethodType.methodType(Arena.class));
>>             case ALLOCATE -> MhUtil.findStatic(LOOKUP, "allocate",
>>                     MethodType.methodType(MemorySegment.class, Arena.class));
>>             case ARENA_CLOSE -> MhUtil.findVirtual(LOOKUP, Arena.class, "close",
>>                     MethodType.methodType(void.class));
>>             default -> throw new InternalError("Unknown index: " + index);
>>         };
>> 
>> Switch statement can be replaced with enhanced 'switch'
>
> I have the old switch format in anticipation of faster startup.

enhanced 'switch' is just syntax sugar and does not affect startup speed

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PR Review Comment: https://git.openjdk.org/jdk/pull/25043#discussion_r2075935264