RFR: 8253742: POSIX signal code cleanup [v3]

[Gerard Ziemski]

On Tue, 3 Nov 2020 10:08:28 GMT, Thomas Stuefe <stuefe at openjdk.org> wrote:

>>> I hadn't realized that JVM_handle_XXX_signal defined a per-platform "public" entry point to allow external callers of the signal handling function in conjunction with -XX:+AllowUserSignalHandlers. We need to keep these but they can each call JVM_handle_posix_signal as their implementation.
>> 
>> We should disentangle https://bugs.openjdk.java.net/browse/JDK-8255711 and this patch, https://bugs.openjdk.java.net/browse/JDK-8253742.
>> 
>> I started by giving my patch a less generic name ("Fix and unify hotspot signal handlers"). I propose to do the same with this patch, or even split this patch into two smaller parts, since it does two things:
>> - unify diagnostic printing code
>> - unify SR handler setup
>> 
>> As I wrote, I'd prefer to keep changes to JVM_xxx and javaSignalHandler out of this patch completely. I have to change those functions since the point of my patch is signal handler unification. 
>> 
>> In turn, I will keep my hands off any other code in signals_posix.xxx to decrease chances of conflict with this patch.
>
>> > I hadn't realized that JVM_handle_XXX_signal defined a per-platform "public" entry point to allow external callers of the signal handling function in conjunction with -XX:+AllowUserSignalHandlers. We need to keep these but they can each call JVM_handle_posix_signal as their implementation.
>> 
>> We should disentangle https://bugs.openjdk.java.net/browse/JDK-8255711 and this patch, https://bugs.openjdk.java.net/browse/JDK-8253742.
>> 
>> I started by giving my patch a less generic name ("Fix and unify hotspot signal handlers"). I propose to do the same with this patch, or even split this patch into two smaller parts, since it does two things:
>> 
>> * unify diagnostic printing code
>> * unify SR handler setup
>> 
>> As I wrote, I'd prefer to keep changes to JVM_xxx and javaSignalHandler out of this patch completely. I have to change those functions since the point of my patch is signal handler unification.
>> 
>> In turn, I will keep my hands off any other code in signals_posix.xxx to decrease chances of conflict with this patch.
> 
> Oh, and yes, I preserve the JVM_handle_xxx_signal entries in my patch, but they are thin wrappers around an internal, posix-specific handler function.

The snapshot of JDK that I'm using in my PR does not build on Windows. Do you have any suggestion how I can safely update to the latest JDK without messing up my PR?

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PR: https://git.openjdk.java.net/jdk/pull/636