Feedback on LW1 EAR

[Tobias Hartmann]

On 22.08.2018 16:49, Uberto Barbini wrote:
> thanks Tobias, I saw you already fixed it!

Yes, thanks again for reporting! It might take a bit until we release another EA build that includes
the fix though (but of course you can just build the JVM from the sources on your own).

Best regards,
Tobias


> On Mon, 20 Aug 2018 at 09:41, Tobias Hartmann <tobias.hartmann at oracle.com
> <mailto:tobias.hartmann at oracle.com>> wrote:
> 
>     Hi Uberto,
> 
>     first of all, thanks a lot for trying out LW1 EA and for reporting these issues!
> 
>     The crash is a bug in the just-in-time (JIT) compiler when compiling the WatchV:equals method, I've
>     filed [1] and will work on a fix.
> 
>     As a temporary workaround you can disable JIT compilation of the affected method via
>     -XX:CompileCommand=exclude,"Knapsack\$WatchV::equals" or disable JIT compilation altogether by
>     adding the -Xint command line flag (unfortunately, both options will slow down execution a lot but
>     it should be good enough for non-performance testing).
> 
>     Thanks,
>     Tobias
> 
>     [1] https://bugs.openjdk.java.net/browse/JDK-8209687
> 
> 
>     On 18.08.2018 12:40, Uberto Barbini wrote:
>     > 5) I saw that I can override toString() and call super.toString() to have
>     > the standard Object behavior. I wonder if there will be some kind of base
>     > class for all ValueTypes or not.
>     >
>     >
>     > Then I've tried to replace some immutable classes into Value Types use them
>     > in my other projects.
>     > The main hindrance has been the missing support for generics.
>     > As workaround I've created a interface and based the collection on the
>     > interface. It worked in a few projects but I had a Fatal Error on a simple
>     > algorithm. I've tried to understand the exact problem but the same code
>     > seems to work as standalone project... If it's something worth
>     > investigating I can dig it more
>     >
>     >
>     https://github.com/uberto/eopi/blob/ValhallaLW01/src/test/java/com/gamasoft/eopi/cap17_DynamicProgramming/KnapsackTest.java
>     >
>     >
>     > #
>     > # A fatal error has been detected by the Java Runtime Environment:
>     > #
>     > #  SIGSEGV (0xb) at pc=0x00007f08c3d648aa, pid=18399, tid=18426
>     > #
>     > # JRE version: OpenJDK Runtime Environment (11.0) (build
>     > 11-lworldea+0-2018-07-30-1734349.david.simms.valhalla)
>     > # Java VM: OpenJDK 64-Bit Server VM
>     > (11-lworldea+0-2018-07-30-1734349.david.simms.valhalla, mixed mode,
>     > compressed oops, g1 gc, linux-amd64)
>     > # Problematic frame:
>     > # V  [libjvm.so+0x4148aa]  AddPNode::Value(PhaseGVN*) const+0x7a
>     > #
>     > # No core dump will be written. Core dumps have been disabled. To enable
>     > core dumping, try "ulimit -c unlimited" before starting Java again
>     > #
>     > # If you would like to submit a bug report, please visit:
>     > #   http://bugreport.java.com/bugreport/crash.jsp
>     > #
>