RFR (S) 8185590: ShouldNotReachHere from ClassLoaderData::try_get_next_class()

[Zhengyu Gu]

How about setup a marker before entering the loop, ensure the loop won't 
come back to initial entry?

#ifdef ASSERT
   Klass* starting_class_entry = _current_class_entry;
#endif

   for (int i = 0; i < max_classes; ) {

   ....

      ASSERT(_current_class_entry != starting_class_entry, ....)
    }

Thanks,

-Zhengyu


On 08/01/2017 10:32 AM, coleen.phillimore at oracle.com wrote:
>
>
> On 8/1/17 10:23 AM, Aleksey Shipilev wrote:
>> On 08/01/2017 04:18 PM, coleen.phillimore at oracle.com wrote:
>>> Summary: Counting number of instanceKlass code didn't work.
>>>
>>> A late code review change caused this regression.   Tested with
>>> internal NSK mlvm tests with
>>> -XX:-TieredCompilation -XX:CompileThreshold=100 including the one
>>> where I reproduced the failure
>>> overnight.
>>>
>>> open webrev at http://cr.openjdk.java.net/~coleenp/8185590.01/webrev
>> Hm, so now that the loop variable is _conditionally_ incremented, what
>> guarantees the loop termination?
>
> The fact that number_of_classes can't be zero so something has to be
> returned?
>
> I had trouble coming up with something better.  If you have a good idea,
> I'll change it.
>
> thanks!
> Coleen
>>
>> Thanks,
>> -Aleksey
>>
>