RFR(S): 8194482: Fix SIGSEGV in print_threads_compiling.

[Vladimir Kozlov]

Looks good.

I will sponsor it and push into JDK 10.

Thanks,
Vladimir

On 1/3/18 4:37 AM, Lindenmaier, Goetz wrote:
> Hi,
> 
> print_threads_compiling prints the tasks compiler threads are working on.
> It gets the task from the thread, checks it for NULL, and then reads the task again from the
> thread. in the meantime, the compiler thread can set the task back to
> NULL so that the check was pointless.
> 
> The task must be read only once.  The field _task must be volatile, so that
> the C-compiler can't re-introduce the read.
> 
> Please review this change. I please need a sponsor. I think this should be fixed
> in 10.
> http://cr.openjdk.java.net/~goetz/wr18/8194482-fixPrintCompThr/webrev.01/
> 
> Best regards,
>    Goetz.
>