RFR: 8342995: Enhance Attach API to support arbitrary length arguments - Linux [v3]

[Serguei Spitsyn]

On Wed, 11 Dec 2024 21:56:20 GMT, Alex Menkov <amenkov at openjdk.org> wrote:

>> The fix updates Linux (and server-side of macosx) implementation to support Attach API v2 (shared code and Windows implementation were introduced by #20782)
>> 
>> 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) with jdk21 and jdk8.
>
> Alex Menkov has updated the pull request incrementally with one additional commit since the last revision:
> 
>   updated comment

The fix looks good modulo a couple of nits.

src/hotspot/share/services/attachListener.cpp line 670:

> 668:     // for v1 also name/arguments should not exceed name_length_max/arg_length_max.
> 669:     if (strlen(name()) > AttachOperation::name_length_max) {
> 670:       log_error(attach)("Failed to read request: name is too long");

Nit: I'd suggest to be more specific: "Failed to read request: attach operation name is too long"

src/hotspot/share/services/attachListener.hpp line 238:

> 236:   virtual void complete(jint result, bufferedStream* result_stream) = 0;
> 237: 
> 238:   class ReplyWriter; //forward declaration

Nit: The comment should start with a space.

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Marked as reviewed by sspitsyn (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/22223#pullrequestreview-2502115945
PR Review Comment: https://git.openjdk.org/jdk/pull/22223#discussion_r1883819157
PR Review Comment: https://git.openjdk.org/jdk/pull/22223#discussion_r1883821145