RFR: 8338383: Implement JEP 491: Synchronize Virtual Threads without Pinning [v12]

[Dean Long]

On Mon, 28 Oct 2024 17:30:44 GMT, Patricio Chilano Mateo <pchilanomate at openjdk.org> wrote:

>> src/hotspot/cpu/aarch64/continuationFreezeThaw_aarch64.inline.hpp line 159:
>> 
>>> 157: 
>>> 158:   // The interpreter native wrapper code adds space in the stack equal to size_of_parameters()
>>> 159:   // after the fixed part of the frame. For wait0 this is equal to 3 words (this + long parameter).
>> 
>> Suggestion:
>> 
>>   // after the fixed part of the frame. For wait0 this is equal to 2 words (this + long parameter).
>> 
>> Isn't that 2 words, not 3?
>
> The timeout parameter is a long which we count as 2 words: https://github.com/openjdk/jdk/blob/0e3fc93dfb14378a848571a6b83282c0c73e690f/src/hotspot/share/runtime/signature.hpp#L347
> I don't know why we do that for 64 bits.

OK, I think there are historical or technical reasons why it's hard to change, because of the way the JVM spec is written.

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PR Review Comment: https://git.openjdk.org/jdk/pull/21565#discussion_r1819705281