RFR 8163969: Cyclic interface initialization causes JVM crash

[Karen Kinnear]

Thank you Coleen - the set_initialization_state_and_notify_impl is even better than I was suggesting.

All sounds good to go!

many thanks,
Karen

> On Sep 20, 2016, at 4:19 PM, Coleen Phillimore <coleen.phillimore at oracle.com> wrote:
> 
> 
> 
> On 9/20/16 1:39 PM, Karen Kinnear wrote:
>> Coleen,
>> 
>> Code looks good. Kudos to you and David Holmes for extremely careful reading of the specification.
> 
> Thank you for the consultation on this bug!
>> 
>> In an earlier web rev you had also made a defensive fix to set_initialization_state_and_notify_impl.
>> Could you possibly add a fix for that?
>> 
>> 1) assertion if init_lock is null
>> 2) for production time: if init_lock is null, at least do not try to dereference ObjectLocker.
> 
> I rewrote the function to assert if init_lock is null but handle the case in product for robustness.
> 
> void InstanceKlass::set_initialization_state_and_notify_impl(instanceKlassHandle this_k, ClassState state, TRAPS) {
>  oop init_lock = this_k->init_lock();
>  if (init_lock != NULL) {
>    ObjectLocker ol(init_lock, THREAD);
>    this_k->set_init_state(state);
>    this_k->fence_and_clear_init_lock();
>    ol.notify_all(CHECK);
>  } else {
>    assert(init_lock != NULL, "The initialization state should never be set twice");
>    this_k->set_init_state(state);
>  }
> }
>> If UseBiasedLocking is disabled, there is a risk of dereferencing null otherwise.
>> 
>> Thank you for the detailed tests.
>> 
>> 3) In InterfaceInitializationStates.java - could you possibly explain the Iunlinked test - what it is testing, what the
>> comment means and what the new bug is?
> 
> Maybe this is better?
> 
>    // Iunlinked is testing initialization like interface I, except interface I is linked when
>    // ClassLIM is linked.
>    // Iunlinked is not linked already when K gets an initialization error.  Linking Iunlinked
>    // should succeed and not get NoClassDefFoundError because it does not depend on the
>    // initialization state of K for linking.  There's bug now where it gets this error.
>    // See: https://bugs.openjdk.java.net/browse/JDK-8166203.
> 
>> 
>> A couple of minor comments/suggestions to make it easier for the person who changes it next on the InterfaceInitializationStates.java tests:
>> 1) line 66 comment refers to ClassL - I think you mean ClassLIM?
> 
> Fixed.
>> 
>> 2) line 61: “Calling function on class with bad super interface.”
>>   I think you want “on class” -> “on interface”
> 
> Yes, thanks.
>> 
>> 3) Could you add a comment before the try on Class.forName that the result of this test is NCDFE because
>> there was an earlier test (ClassLIM) that already initialized K?
> 
>        // Test that K already has initialization error so gets ClassNotFoundException because
>        // initialization was attempted with ClassLIM.
>> 
>> 4) line 143: “K (sub interface)” -> “K (super interface)”
> 
> Fixed.
>> 
>> 5) lines 155-156 “K, its superclass state” -> “K (its super interface) is in initialization_error state.
> 
> Yes, that reads better.
> 
> Thanks for the comments and careful review on this fix!
> 
> Coleen
> 
>> 
>> thanks
>> Karen
>> 
>> 
>>> On Sep 16, 2016, at 11:22 AM, Coleen Phillimore <coleen.phillimore at oracle.com> wrote:
>>> 
>>> Summary: Fix interface initialization to follow spec: interface initializations do not set initialization state of interfaces that extend them.
>>> 
>>> Tested with: all hotspot jtreg tests, co-located nsk tests, non-colocated nsk tests, and jck tests.
>>> 
>>> open webrev at http://cr.openjdk.java.net/~coleenp/8163969.01/webrev
>>> bug link https://bugs.openjdk.java.net/browse/JDK-8163969
>>> 
>>> Thanks,
>>> Coleen
>