Request for reviews (S): 6730276: JDI_REGRESSION tests fail with "Error: count must be non-zero" error on x86

[Paul Hohensee]

Even though you don't want to rely on it. :)  It should give you some 
idea of
what to check, and if it's inaccurate, it should be updated.

Paul

On 6/9/10 4:20 PM, Paul Hohensee wrote:
> Look at src/share/vm/utilities/copy.hpp, which should note which Copy
> methods check for zero length and which do not.
>
> Paul
>
> On 6/9/10 3:55 PM, Vladimir Kozlov wrote:
>> Yes, some methods have zero count check but some does not.
>> And I don't want to relay on current code in copy.hpp.
>> It seems I have to go through all implementations, verify
>> zero count check and add comments.
>>
>> Which are most used copy methods?
>> I will look that they will not have duplicated checks.
>>
>> Thanks,
>> Vladimir
>>
>> John Coomes wrote:
>>> Paul Hohensee (paul.hohensee at oracle.com) wrote:
>>>> Actually, gc copying is done by pd_disjoint_words, which checks for a
>>>> zero length already.
>>>
>>> Vladimir is adding an extra check to that path, in
>>> Copy::disjoint_words* :-(.
>>>
>>> -John
>>>
>>>> On 6/9/10 3:13 PM, John Coomes wrote:
>>>>> Vladimir Kozlov (vladimir.kozlov at oracle.com) wrote:
>>>>>> http://cr.openjdk.java.net/~kvn/6730276/webrev
>>>>>>
>>>>>> Fixed 6730276: JDI_REGRESSION tests fail with "Error: count must 
>>>>>> be non-zero" error on x86
>>>>>>
>>>>>> Replace assert_non_zero with if (count == 0) return.
>>>>> The code change is fine, as long as there's no performance hit in GC.
>>>>> The heaviest user of these routines is GC, and we call only when
>>>>> there's something to copy.
>>>>>
>>>>> -John
>>>>>
>>>