RFR: 8252324: Signal related code should be shared among POSIX platforms

[Gerard Ziemski]

On Wed, 23 Sep 2020 13:11:42 GMT, Gerard Ziemski <gziemski at openjdk.org> wrote:

> > _Mailing list message from [Doerr, Martin](mailto:martin.doerr at sap.com) on
> > [hotspot-runtime-dev](mailto:hotspot-runtime-dev at openjdk.java.net):_ Hi Gerard,
> > sorry for the long delay. It took time to get our nightly tests working again on AIX.
> > I have seen an issue, but it may be unrelated to your change. We'll retest it.
> 
> I will take another look at AIX changes to see if I missed something.
> 
> > Note that there's still unused code left in os_aix.cpp (see below).
> > Thanks again for taking care of AIX. I appreciate having more shared POSIX code.
> 
> Thank you for the diff, I'll use it and update the webrev.

I took another look at the changes and I have concerns over the following methods:

PosixSignals::SR_handler
PosixSignals::do_suspend
PosixSignals::do_resume

They seem to differ substantially in parts from the other POSIX platforms. In my early webrevs I have accounted for
those changes using "#if defined(AIX)", but during pre-reviews you asked me to revert to the common POSIX code.

Can you please take a look again and tell me if you are OK with the following SA related changes:

- using POSIX semaphores
- using the common POSIX code

I will upload, what I think (based only on the code diffs between the platforms as I lack AIX platform understanding)
the AIX platform needs here.

-------------

PR: https://git.openjdk.java.net/jdk/pull/157