UnsatisfiedLinkError: cannot find native jdk.internal.reflect.Reflection.getClassAccessFlags

[gayanW]

Runtime error "java.lang.UnsatisfiedLinkError: cannot find native jdk.internal.reflect.Reflection.getClassAccessFlags" when running CountDownLatchTest

[junit] java.lang.UnsatisfiedLinkError: cannot find native jdk.internal.reflect.Reflection.getClassAccessFlags
[junit]     at jdk.internal.reflect.Reflection.getClassAccessFlags(gov.nasa.jpf.vm.JPF_jdk_internal_reflect_Reflection)
[junit]     at sun.invoke.util.VerifyAccess.getClassModifiers(VerifyAccess.java:156)
[junit]     at sun.invoke.util.VerifyAccess.isClassAccessible(VerifyAccess.java:177)
[junit]     at java.lang.invoke.MethodHandles$Lookup.checkSymbolicClass(MethodHandles.java:2047)
[junit]     at java.lang.invoke.MethodHandles$Lookup.resolveOrFail(MethodHandles.java:2020)
[junit]     at java.lang.invoke.MethodHandles$Lookup.findVarHandle(MethodHandles.java:1516)
[junit]     at java.util.concurrent.locks.AbstractQueuedSynchronizer.<clinit>(AbstractQueuedSynchronizer.java:2301)
[junit]     at java.util.concurrent.CountDownLatch.<init>(CountDownLatch.java:201)
[junit]     at gov.nasa.jpf.test.java.concurrent.CountDownLatchTest.testCountDown(CountDownLatchTest.java:43)

The above error follows after the PR #104

[cyrille-artho]

As far as I can tell, JPF currently does not search inner classes (perhaps it should), so we can probably get away with delegating this to Class.getModifiers().
The native peer for that method is public int getModifiers____I (MJIEnv env, int clsRef).

[gayanW]

When you say 'search' did you mean the resolving of the classes?. If so, I could confirm that it resolves not just the superclasses and interfaces of a requested class but also its static inner classes (eg: java.lang.String$CaseInsensitiveComparator), and nested interfaces (eg: java.lang.Thread$UncaughtExceptionHandler)

[gayanW]

Reflection#getClassAccessFlags(java.lang.Class) is only called about twice for entire test units. I think it is safe to say that the native int getClassAccessFlags(Class<?> c) is never called with an inner class as the argument c, while running the tests.

I've tried the following implementation:

  /**
   * NativePeer method for {@link jdk.internal.reflect.Reflection#getClassAccessFlags(java.lang.Class)}
   */
  @MJI
  public static int getClassAccessFlags__Ljava_lang_Class_2__I(MJIEnv env, int clsObjRef, int cRef) {
    try {
      ClassInfo classInfo = env.getClassInfo(cRef);
      Class<?> c = Class.forName(classInfo.getName());
      return c.getModifiers();

    } catch (ClassNotFoundException e) {
      return MJIEnv.NULL;
    }
  }

But I'm not quite sure about the following code snippet:

  ClassInfo classInfo = env.getClassInfo(cRef);
  Class<?> c = Class.forName(classInfo.getName());

Is this the correct approach to retrieve a Class object associated with given class reference (int cRef)?

[cyrille-artho]

Yes, I meant the mechanism of searching super classes/interfaces for methods that cannot be found in the current class.

[cyrille-artho]

ClassInfo classInfo = env.getClassInfo(cRef); Class<?> c = Class.forName(classInfo.getName());

Thanks for asking. This would get the information about class ClassInfo, not the class that you're actually looking for. Instead, return the modifiers from classInfo itself:
return classInfo.getModifiers();