RFR: 8226816: add UserHandler calls to event log

[David Holmes]

Hi Matthias,

On 27/06/2019 6:56 pm, Baesken, Matthias wrote:
> Hello, please review  the following  small  patch .
> It adds  event logging to  the UserHandler  (user signal handler) calls .

That seems reasonable.

> (additionally  it adds   a function   os::win32::get_signal_name
> to get  signal names for signal numbers ; this is similar to what we already had for posix ).

If you add this then we don't need distinct POSIX and non-POSIX versions 
- the existing os::Posix::get_signal_name etc could all be hoisted into 
os.cpp and the os class - no?

Aside: I spotted this in UserHandler:

     // 4511530 - sem_post is serialized and handled by the manager 
thread. When
     // the program is interrupted by Ctrl-C, SIGINT is sent to every 
thread. We
     // don't want to flood the manager thread with sem_post requests.
     if (sig == SIGINT && Atomic::add(1, &sigint_count) > 1)
       return;

That's a LinuxThreads anachronism which has been copied, unnecessarily 
into the other OS implementations. I will file a RFE to get rid of it.

Thanks,
David

> 
> 
> Bug/webrev :
> 
> https://bugs.openjdk.java.net/browse/JDK-8226816
> 
> http://cr.openjdk.java.net/~mbaesken/webrevs/8226816.0/
> 
> Thanks, Matthias
>