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

[David Holmes]

On Sat, 3 Oct 2020 17:12:30 GMT, Gerard Ziemski <gziemski at openjdk.org> wrote:

> This is a fresh start for https://github.com/openjdk/jdk/pull/157
> 
> Please review this change that refactors common POSIX code into a separate
> file.
> 
> Currently there appears to be quite a bit of duplicated code among POSIX
> platforms, which makes it difficult to apply single fix to the signal code.
> With this fix, we will only need to touch single file for common POSIX
> code fixes from now on.
> 
> ---------
> ### Progress
> - [x] Change must not contain extraneous whitespace
> - [x] Commit message must refer to an issue
> - [ ] Change must be properly reviewed
> 
> 
> 
> ### Download
> `$ git fetch https://git.openjdk.java.net/jdk pull/497/head:pull/497`
> `$ git checkout pull/497`

This looks good.

One request to delete a meaningless comment block.

Thanks,
David

src/hotspot/os/posix/signals_posix.cpp line 1574:

> 1572:   // supported Bsd platforms). Note that BsdThreads/LinuxThreads need to block
> 1573:   // this signal for all threads to work properly. So we don't have
> 1574:   // to use hard-coded signal number when setting up the mask.

This comment block (lines 1571-1574) should be deleted. It was originally in the Linux code and pertained to the old
LinuxThreads implementation which has not been relevant for years. It was erroneously copied across to the BSD port,
where Linux was globally replaced with Bsd, resulting in a reference to the non-existent BsdThreads.

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

Changes requested by dholmes (Reviewer).

PR: https://git.openjdk.java.net/jdk/pull/497