RFR(s): 8143291: Remove redundant coding around os::exception_name

[Thomas Stüfe]

Ping...

Could I have a second review please?

The current webrev is:
http://cr.openjdk.java.net/~stuefe/webrevs/8143291/webrev.03/webrev/
And the bug report:    https://bugs.openjdk.java.net/browse/JDK-8143291

Thank you!

..Thomas


On Thu, Nov 19, 2015 at 11:23 AM, Thomas Stüfe <thomas.stuefe at gmail.com>
wrote:

> Hi,
>
> please take a look at this change.
>
> bug: https://bugs.openjdk.java.net/browse/JDK-8143291
> webrev:
> http://cr.openjdk.java.net/~stuefe/webrevs/8143291/webrev.00/webrev/
>
> This fix does some cleanups around os::exception_name().
>
> - os::exception_name() is identical on all Posix platforms (it returns a
> signal name string for a signal number), so it can be merged into
> os_posix.cpp
>
> - There is no need for a platform-specific implementation, as we have
> already os::Posix::get_signal_name(). Use that instead of platform-specific
> solutions.
>
> - I added a function os::Posix::get_signal_number() which is the inverse
> of os::Posix::get_signal_name().
>
> - Before, a signal-to-number table was kept in jvm_<os>.cpp. That was used
> to implement os::exception_name() and also for JVM_FindSignal
> -> on AIX, I removed the coding altogether and used
> os::Posix::get_signal_number() as a base for JVM_FindSignal.
> -> on the other Unices, I did not feel so confident, because strictly
> spoken we may change the behaviour slightly to before:
> os::Posix::get_signal_name() knows more signal names than the platform
> specific tables knew before, so now Signal.findSignal("<name>") would
> return more matches than before.
> I am not sure whether I am overcautious here - should I treat the other
> Unices the same way I treated AIX, i.e. implement
> Signal.findSignal("<name>") -> JVM_FindSignal via
> os::Posix::get_signal_number()? This would further simplify the coding.
>
> Oh, this fix also fixes an issue where os::exception_name() would return
> NULL for an unknown signal number, but no caller ever checks for NULL
> before printing the result. The new os::exception_name() always returns a
> string and also distinguishes between "unknown but valid signal" and
> "invalid signal".
>
> Kind Regards, Thomas
>
>
>