RFR: 8359064: Expose reason for marking nmethod non-entrant to JVMCI client [v8]

[Tom Rodriguez]

On Wed, 18 Jun 2025 17:29:45 GMT, Cesar Soares Lucas <cslucas at openjdk.org> wrote:

>> src/hotspot/share/code/nmethod.hpp line 500:
>> 
>>> 498:     WHITEBOX_DEOPTIMIZATION,
>>> 499:     ZOMBIE,
>>> 500:     LAST_REASON
>> 
>> This isn't really the last reason, since it's not actually a reason.  So either `LAST_REASON = ZOMBIE` with adjustments to the range check or maybe `REASON_COUNT`?  Why do we need `UNKNOWN` since it seems unused?
>
> I'll looked other enums in HotSpot and there was a mixed of `*_COUNT`, `LAST_*`, etc. I opted to use `LAST_*` for no particular 'reason'. I'll change to `REASON_COUNT` as you suggest.

Yes it's kind of a messy mix of idioms.  The first/last pattern is usually for aliases for other values.

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

PR Review Comment: https://git.openjdk.org/jdk/pull/25706#discussion_r2155199944