RFR: 8359437: Make users and test suite not able to set LockingMode flag [v5]

[Alan Bateman]

On Tue, 24 Jun 2025 13:25:20 GMT, Anton Artemov <duke at openjdk.org> wrote:

>> This PR contains changes for the 1st phase of the `LockingMode` flag obsoletion. 
>> 
>> The work is done by @fbredber, I have taken it over and am finishing it while he's on vacation. 
>> 
>> In the 1st phase one keeps the `LockingMode` variable in all places, but makes it non-settable from the command line. All the C1 and C2 code related to legacy locking will still be in place (but as dead code) and removed later (phase 2).
>> 
>> Lightweight locking is the default locking from now on.
>> 
>> Tested in tiers 1 - 7.
>
> Anton Artemov has updated the pull request incrementally with one additional commit since the last revision:
> 
>   8359437: Addressed reviewer's comment

test/jdk/jdk/internal/vm/Continuation/Fuzz.java line 477:

> 475:     boolean shouldPin() {
> 476:         // Returns false since we never pin after we removed legacy locking.
> 477:         return traceHas(Op.PIN::contains) && false;

Are you planning to remove this method and update verifyPin, or maybe there will be a follow-on JBS issue for this cleanup?

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PR Review Comment: https://git.openjdk.org/jdk/pull/25847#discussion_r2166459367