JTReg Test Failure: java/lang/annotation/loaderLeak/Main.java

[adam-thorpe]

Failure link

• Test: https://github.com/ibmruntimes/openj9-openjdk-jdk11/blob/openj9/test/jdk/java/lang/annotation/loaderLeak/Main.java
• Build: https://ci.adoptopenjdk.net/view/Test_grinder/job/Grinder/1870
• Test Category: openjdk
• Test Suite Name: jdk_lang
• OS/Architecture: x86-64-windows, x86-64-linux, x86-64-osx, ...
• OpenJDK Version: 11.0.4+11
• Public Build SHAs:
• OpenJ9 - 4baf3d7e4
• OMR - 6e99760b
• JCL - 965d0c0df3

Optional info

• Intermittent failure: No
• Regression or new test: Regression
• Part of the excluded jdk11 openj9 JTReg Tests: https://github.com/AdoptOpenJDK/openjdk-tests/issues/585

Failure output (captured from console output)

Note: Main.java uses or overrides a deprecated API.
Note: Recompile with -Xlint:deprecation for details.
Note: Main.java uses unchecked or unsafe operations.
Note: Recompile with -Xlint:unchecked for details.
Exception in thread "main" java.lang.AssertionError
        at Main.doTest(Main.java:56)
        at Main.main(Main.java:41)

[pdbain-ibm]

Reproduced locally. Investigating...

[pdbain-ibm]

This test is invalid.

        ClassLoader loader = new SimpleClassLoader();
        WeakReference<Class<?>> c = new WeakReference(loader.loadClass("C"));   <<< line 49
        if (c.get() == null) throw new AssertionError();
        if (c.get().getClassLoader() != loader) throw new AssertionError();
        if (readAnn) System.out.println(c.get().getAnnotations()[0]);
        if (c.get() == null) throw new AssertionError();
        System.gc();
        System.gc();
        if (c.get() == null) throw new AssertionError(); <<< Failing line 56

Line 49 creates a weak reference to the Class object for C. It then runs two GCs, which clear the weak reference to the Class object because there are no strong references to the object, as designed.