Question regarding JVM crashes in GC

[Stefan Johansson]

Hi Michael,

On 2017-04-05 09:11, Michael Rasmussen wrote:
> Ok
>
> Found Shipilev's fastdebug builds, and tried running with that
> (openjdk-jdk9-dev-fastdebug-2017-04-04.tar.gz).
>
> Using the fastdebug build and running with G1, the JVM crashes when
> calling System.gc(), with one of the following assertions:
>
> Internal Error (hotspot/src/share/vm/gc/serial/markSweep.inline.hpp:61)
> assert(is_archive_object(obj) || new_obj != __null || obj->mark() ==
> markOopDesc::prototype() || (UseBiasedLocking &&
> obj->mark()->has_bias_pattern())) failed: should be forwarded
>
> Internal Error (hotspot/src/share/vm/gc/serial/markSweep.inline.hpp:53)
> assert(Universe::heap()->is_in(obj)) failed: should be in heap
>
> Internal Error (hotspot/src/share/vm/gc/serial/markSweep.inline.hpp:65)
> assert(Universe::heap()->is_in_reserved(new_obj)) failed: should be in
> object space
All these assertions are in MarkSweep::adjust_pointer and they suggest 
that you are visiting an object with bad references. What's causing this 
is really hard to say without more information. It sounds like this is 
easy for you to reproduce, could we run the same tests ourselves? Or 
could you construct a reproducer that we can run?

Thanks,
Stefan

> /Michael