RFR: 8369631: Assess and remedy any unsafe usage of the sr_semaphore Semaphore in the Posix signal code [v2]

[Kim Barrett]

On Wed, 15 Oct 2025 12:24:04 GMT, David Holmes <dholmes at openjdk.org> wrote:

>> src/hotspot/os/posix/signals_posix.cpp line 356:
>> 
>>> 354:   // Initialize signal semaphore
>>> 355:   int sem_count = 0;
>>> 356:   sig_semaphore.initialize(sem_count);
>> 
>> Just `sig_semaphore.initialize();` should be work. And the variable declaration looks kind of odd in context.
>
> I was not sure how the "magic" of initialization worked in this case with default constructor arguments - plus I wanted to be explicit about the initial count. Unfortunately the template requires a reference hence the local was introduced - if there is a better way to do this please advise me.

There is a better way. `initialize` should use perfect forwarding. Sigh.
OK, leave it as is.  It can be fixed later, once we allow perfect forwarding.

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PR Review Comment: https://git.openjdk.org/jdk/pull/27762#discussion_r2436590698