FW: is this a bug ?

[Yangfei (Felix)]

> > >
> > > But have you actually see it fail? I don't see how, as test grading
> > > accepts all results.
> >
> > Yes, it fails randomly on our 128-core aarch64 server platform.
> >
> > Part of the report was:
> >
> > ERROR tests
> > Tests break for some reason, other than failing the assert. Correct
> > implementations should have none.
> >
> >
> > o.o.j.t.atomicity.buffers.DirectByteBufferViewsAtomicityTests.LongView
> > Test
> >
> > Exception in thread "main" java.lang.IllegalStateException: Should
> > have been handled within the Runner
> > 	at org.openjdk.jcstress.JCStress.runEmbedded(JCStress.java:248)
> > 	at org.openjdk.jcstress.ForkedMain.main(ForkedMain.java:55)
> > JVM options: [-XX:+UnlockDiagnosticVMOptions, -XX:+WhiteBoxAPI,
> > -XX:-RestrictContended, -XX:-TieredCompilation,
> > -XX:ReservedCodeCacheSize=128M, -server] Iterations: 5 Time: 1000
> 
> Some of our analysis:
> 
>  51         private final LongBuffer lb;
>  52         private final ShortBuffer sb;
>  53
>  54         public MyState() {
>  55             b = ByteBuffer.allocate(16);
>  56             b.order(ByteOrder.nativeOrder());
>  57             ib = b.asIntBuffer();
>  58             cb = b.asCharBuffer();
>  59             db = b.asDoubleBuffer();
>  60             fb = b.asFloatBuffer();
>  61             lb = b.asLongBuffer();
>  62             sb = b.asShortBuffer();
>  63         }
> 
> 94     @JCStressTest
>  95     @JCStressMeta(GradeInt.class)
>  96     public static class LongViewTest {
>  97         @Actor public void actor1(MyState s)
> { s.lb.put(0, -1);                                  }
>  98         @Actor public void actor2(MyState s, J_Result r) { r.r1 =
> s.lb.get(0);                               }
>  99     }
> 
> For the LongBuffer.put & LongBuffer.get operation, the atomicity is different
> when b is assigned a DirectByteBuffer.  Please check.


Based on that, I think "org.openjdk.jcstress.tests.atomicity.buffers.ByteBufferViewsAtomicityTests.LongViewTest" has the same problem.  

I can also reproduce this problem on X86-64 platform with 8u jdk by running: 
$ java -XX:+UnlockDiagnosticVMOptions -XX:+WhiteBoxAPI -XX:-RestrictContended -XX:ReservedCodeCacheSize=128M -jar /home/yangfei/tools/jcstress.jar -t "org.openjdk.jcstress.tests.atomicity.buffers.ByteBufferViewsAtomicityTests.LongViewTest" -time 50000


Looks like both tests always fail with the following exception: 
Exception in thread "main" java.lang.OutOfMemoryError: Java heap space
        at org.openjdk.jcstress.util.OpenAddressHashCounter.resize(OpenAddressHashCounter.java:130)
        at org.openjdk.jcstress.util.OpenAddressHashCounter.recordWithTries(OpenAddressHashCounter.java:108)
        at org.openjdk.jcstress.util.OpenAddressHashCounter.record(OpenAddressHashCounter.java:77)
        at org.openjdk.jcstress.util.OpenAddressHashCounter.merge(OpenAddressHashCounter.java:83)
        at org.openjdk.jcstress.tests.atomicity.buffers.ByteBufferViewsAtomicityTests_LongViewTest_jcstress.internalRun(ByteBufferViewsAtomicityTests_LongViewTest_jcstress.java:78)
        at org.openjdk.jcstress.infra.runners.Runner.run(Runner.java:101)
        at org.openjdk.jcstress.JCStress.runEmbedded(JCStress.java:246)
        at org.openjdk.jcstress.ForkedMain.main(ForkedMain.java:55)

Note that I am using an old jcstress version in order to run it with a 8u jdk.  I execute " hg update -r 0de8079ec104 " to get the old version.  

Thanks,
Felix