RFR(M): 8210754: print_location is not reliable enough (printing register info)

[David Holmes]

Hi Martin,

On 15/09/2018 12:03 AM, Doerr, Martin wrote:
> Hi,
> 
> I'd like to make os::print_location more reliable which is used in error reporting step "printing register info". Oops and Klasses should get inspected more carefully.

But some of what you are doing is accessing shared state that could be 
mutated concurrently with the error reporting thread that is trying to 
read it e.g. walking the ClassLoaderDataGraph!

David
-----

> I have seen errors like "[error occurred during error reporting (printing register info), id 0xe0000000, Internal Error (/usr/work/d056149/openjdk/jdk/src/hotspot/share/oops/klass.inline.hpp:63)]" in many hs_err files.
> 
> Bug:
> https://bugs.openjdk.java.net/browse/JDK-8210754
> 
> Webrev:
> http://cr.openjdk.java.net/~mdoerr/8210754_print_location/webrev.00/
> 
> Sometimes, I get such errors when using -XX:+CrashGCForDumpingJavaThread, sometimes when injecting crashing code into compiled methods which I did by the following code:
> http://cr.openjdk.java.net/~mdoerr/crash_C2_method/webrev.00/
> I can also contribute this if it's desired. Automatic tests would certainly be nice to have. Maybe I can find some time for that.
> 
> Please review.
> 
> Best regards,
> Martin
>