RFR 8145964: NoClassDefFound error in transforming lambdas

[Coleen Phillimore]

On 8/10/16 8:37 PM, David Holmes wrote:
> Hi Coleen,
>
> On 11/08/2016 12:45 AM, Coleen Phillimore wrote:
>>
>> New webrev:
>>
>>
>> http://cr.openjdk.java.net/~coleenp/8145964.02/webrev/index.html
>
> First I'm very surprised that the existing logic in 
> JvmtiEnv::RetransformClasses doesn't utilize 
> VM_RedefineClasses::is_modifiable_class to determine when to return 
> JVMTI_ERROR_UNMODIFIABLE_CLASS. It would seem easy for the two bits of 
> code to get out of sync!
>
> Second, why do you silently ignore an attempt to redefine an anonymous 
> class instead of returning JVMTI_ERROR_UNMODIFIABLE_CLASS? The 
> restriction on transforming anonymous classes seems no different to me 
> to the restriction on transforming primitive or array classes.

I believe that there are existing applications, as in the test, get all 
the loaded classes and try to transform them.  These will get the VM 
anonymous class, so we didn't want to give them an error. Or set CLFH 
and vm anonymous classes fall into the load hook. There's another bug 
that Rachel has that ignores them for CFLH (rather than crashing).

 From the Java standpoint, the existence of vm anonymous classes are a 
implementation detail and not real classes, and it's better to hide 
these as much as possible.

Coleen

>
> Thanks,
> David
>
>> Reran jvmti tests.
>>
>> Thanks,
>> Coleen
>>
>> On 8/10/16 9:32 AM, Coleen Phillimore wrote:
>>>
>>>
>>> On 8/9/16 7:40 PM, David Holmes wrote:
>>>> Hi Coleen,
>>>>
>>>> On 10/08/2016 4:52 AM, Coleen Phillimore wrote:
>>>>> Summary: Skip VM anonymous classes in retransformation and give an
>>>>> error
>>>>> for redefinition.
>>>>>
>>>>> Contributed by Tom Rodriguez.
>>>>>
>>>>> Tested with redefinition colocated tests (tonga) and
>>>>> java/lang/instrument tests, and added test case.
>>>>>
>>>>> open webrev at http://cr.openjdk.java.net/~coleenp/8145964.01/webrev
>>>>> bug link https://bugs.openjdk.java.net/browse/JDK-8145964
>>>>
>>>> Shouldn't anonymous classes be added to the set of non-modifiable
>>>> classes - so IsModifiableClass returns false and we just add this
>>>> case to VM_RedefineClasses::is_modifiable_class.
>>>
>>> Yes, that might be a better way to do it.
>>> thanks,
>>> Coleen
>>>
>>>>
>>>> ??
>>>>
>>>> Thanks,
>>>> David
>>>>
>>>>> Thanks,
>>>>> Coleen
>>>
>>