Probably a bug

[Aleksey Shipilev]

On 2/24/20 11:22 PM, Kirill A. Korinsky wrote:
> After playing really a while I've created a very trivial test case: https://github.com/catap/shenandoah-akka-bug <https://github.com/catap/shenandoah-akka-bug>

Thank you.

It can be run without docker-compose with just a naked JDK binary.

This reliably fails with Future timeout for me:

$ mvn package
$ cd target/shenandoah-akka-bug-1.0.0-dist/shenandoah-akka-bug-1.0.0
$ EXTERNAL_ADDR=127.0.0.1
~/trunks/shenandoah-jdk8/build/linux-x86_64-normal-server-fastdebug/images/j2sdk-image/bin/java
-Xmx1g -XX:+UseShenandoahGC -XX:+UnlockDiagnosticVMOptions -XX:ShenandoahGCHeuristics=aggressive
-XX:TieredStopAtLevel=1 -jar bin/shenandoah-akka-bug-1.0.0.jar

What it seems to tell me:
 a) It fails only with -XX:TieredStopAtLevel=1. It does not seem to fail with -Xint or
-XX:-TieredCompilation, which suggests this is C1 problem;
 b) It does not seem to fail with -XX:ShenandoahGCMode=passive, which suggests this trouble  is
somewhere in Shenandoah C1 barriers or around it;
 c) It does not fail with -XX:ShenandoahGCMode=passive and all barriers enabled back, which suggests
it is somewhere in the mid/slowpath of Shenandoah C1 barrier.

-- 
Thanks,
-Aleksey