Valhalla ArrayCopyStoreNull test failure

[hangshao0]

Failure link

https://hyc-runtimes-jenkins.swg-devops.com/view/Valhalla%20Tests/job/Test_JDKnext_valhalla_openjdk_x86-64_linux/121/console

Failure output (captured from console output)

19:17:17  openjdk version "28-internal" 2027-03-23
19:17:17  OpenJDK Runtime Environment (build 28-internal-adhoc.jenkins.BuildJDKnextx86-64linuxvalhallaNightly)
19:17:17  Eclipse OpenJ9 VM (build 28-internal-adhoc.jenkins.BuildJDKnextx86-64linuxvalhallaNightly-master-619bdfdf675, JRE 28 Linux amd64-64-Bit Compressed References 20260628_2313 (JIT enabled, AOT enabled)
19:17:17  OpenJ9   - 619bdfdf675
19:17:17  OMR      - a39ef2b2cfd
19:17:17  JCL      - af57611f4df based on jdk-28+4)
...

19:22:54  java.lang.ArrayStoreException
19:22:54  	at java.base/java.lang.System.arraycopy(Native Method)
19:22:54  	at runtime.valhalla.inlinetypes.ArrayCopyStoreNull.main(ArrayCopyStoreNull.java:55)
19:22:54  	at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:104)
19:22:54  	at java.base/java.lang.reflect.Method.invoke(Method.java:589)
19:22:54  	at com.sun.javatest.regtest.agent.MainWrapper$MainTask.run(MainWrapper.java:138)
19:22:54  	at java.base/java.lang.Thread.run(Thread.java:1538)
...
19:29:30  FAILED test targets:
19:29:30  	hotspot_valhalla_runtime_j9_0 - Test results: passed: 50; failed: 1; excluded: 72; did not match keywords: 6; did not meet platform requirements: 16 
19:29:30  		Failed test cases: 
19:29:30  			TEST: runtime/valhalla/inlinetypes/ArrayCopyStoreNull.java
19:29:30          
19:29:30  	hotspot_valhalla_runtime_j9_1 - Test results: passed: 50; failed: 1; excluded: 72; did not match keywords: 6; did not meet platform requirements: 16 
19:29:30  		Failed test cases: 
19:29:30  			TEST: runtime/valhalla/inlinetypes/ArrayCopyStoreNull.java

[hangshao0]

Might be related to the array copy issue you are working on: @Harshitha-Popuri

[hangshao0]

This is caused by exception mismatch. OpenJ9 throws ArrayStoreException but the test is expecting NullPointerException.

[harship04]

test:https://github.com/ibmruntimes/openj9-openjdk-jdk.valuetypes/blob/openj9/test/hotspot/jtreg/runtime/valhalla/inlinetypes/ArrayCopyStoreNull.java

The bug is in copyFlattenableArray. The helper objectArrayStoreAllowed correctly rejects storing null into a null-restricted array, but copyFlattenableArray doesn't distinguish why the store failed. It always returns -1, which becomes ArrayStoreException. Storing null into a null-restricted array should result in NullPointerException. The fix is to detect the null with null-restricted case and return -2 instead, allowing the caller to throw NullPointerException .

openj9/runtime/vm/ValueTypeHelpers.hpp

Line 597 in d2efd20

if (typeChecksRequired) {

[harship04]

I tried running the sanity.functional tests after making the change. Three tests are now failing:

org.openj9.test.lworld.ValueTypeSystemArraycopyTests.testSystemArrayCopy22
org.openj9.test.lworld.ValueTypeSystemArraycopyTests.testSystemArrayCopy23
org.openj9.test.lworld.ValueTypeSystemArraycopyTests.testSystemArrayCopy29

openj9/test/functional/Valhalla/src_qtypes/org/openj9/test/lworld/ValueTypeSystemArraycopyTests.java

Line 647 in d2efd20

static public void testSystemArrayCopy22() throws Throwable {

According to my understanding these tests copy null into a null-restricted value array and currently expect an ArrayStoreException. My change detects this case earlier in copyFlattenableArray() and returns -2, which causes the caller to throw a NullPointerException instead. As a result, the tests fail because they are expecting ArrayStoreException, whereas the runtime now throws NullPointerException.

failing jenkins link:https://hyc-runtimes-jenkins.swg-devops.com/job/Test_openjdkvalhalla_j9_sanity.functional_x86-64_linux_valhalla_Personal/292/#showFailuresLink

[hangshao0]

In the draft JEP, it says ArrayStoreException when storing null to a null restricted array:

a2[1] = null; // ArrayStoreException

It looks like the spec and RI's behavior is inconsistent. We can change ValueTypeSystemArraycopyTests.java to accept both ArrayStoreException and NullPointerException for now.

[harship04]

should I update all the relevant tests to accept both ArrayStoreException and NullPointerException, or only testSystemArrayCopy22, testSystemArrayCopy23, and testSystemArrayCopy29?

I thought these were the only tests that exercise the null into a null-restricted array case, since they're the only ones failing when I ran sanity.functional test after my change, by modifying them to catch NullPointerException instead of ArrayStoreException.

[hangshao0]

should I update all the relevant tests to accept both ArrayStoreException and NullPointerException, or only testSystemArrayCopy22, testSystemArrayCopy23, and testSystemArrayCopy29?

You need to only update the ones that failed with #24385 due to the change of exception type when storing null to a null restricted array.