RFR: 8339289: Parameter size mismatch between client and VM sides of the Attach API - Windows [v3]

[Serguei Spitsyn]

On Tue, 15 Oct 2024 00:21:41 GMT, Alex Menkov <amenkov at openjdk.org> wrote:

>> The fix improves Attch API protocol and implements updated protocol on windows; shared code is ready to implement updated protocol support on other platforms.
>> More detailed explanations on the 1st comment.
>> 
>> Testing: tier1,tier2,tier3,tier4,hs-tier5-svc
>>   manually tested backward compatibility (old tools can attach to current VMs, current tools can attach to older VMs) on Windows with jdk21u and jdk8u.
>
> Alex Menkov has updated the pull request incrementally with one additional commit since the last revision:
> 
>   renamed JVM_EnqueueOperation2
>   
>   renamed JVM_EnqueueOperation2 to JVM_EnqueueOperation_v2 for consistency (per Serguei request)

I've posted some nits and one questions.
Otherwise, this change looks good to me.

src/hotspot/os/windows/attachListener_windows.cpp line 194:

> 192:   }
> 193:   const char* arg(int i) const {
> 194:     return (i >= 0 && AttachOperation::arg_count_max) ? _arg[i] : nullptr;

Nit: Dot is not needed at the end of comment at line 140.
Q: Should the condition at line 194 be modified as below:
   ```return (i >= 0 && i < AttachOperation::arg_count_max) ? _arg[i] : nullptr;```

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PR Review: https://git.openjdk.org/jdk/pull/20782#pullrequestreview-2368827594
PR Review Comment: https://git.openjdk.org/jdk/pull/20782#discussion_r1800860402