RFR(S) 8199924: Solaris: Correctly enqueue null arguments of attach operations

[Daniel D. Daugherty]

On 3/21/18 10:23 AM, Daniel D. Daugherty wrote:
> On 3/21/18 10:00 AM, Langer, Christoph wrote:
>> Hi Dan,
>>
>> that is, you mean the C-code? My original change?
>
> Hmmm... I think I confused myself before I drank enough coffee...
> Looking again...

Okay I definitely confused myself... and I clearly don't remember
the attach-on-demand code as well as I used to... sigh...

I think you should keep your original fix since it now properly
handles null arguments at the same attach-on-demand layer as the
Linux code that you quoted.

Handling this in args array processing would also be possible
as David suggests, but it would bother me that Linux and Solaris
lower attach-on-demand layers would have different behaviors.

Hope this is more clear.

Dan


>
> Dan
>
>
>>
>> Best regards
>> Christoph
>>
>>> -----Original Message-----
>>> From: Daniel D. Daugherty [mailto:daniel.daugherty at oracle.com]
>>> Sent: Mittwoch, 21. März 2018 14:59
>>> To: Langer, Christoph <christoph.langer at sap.com>; David Holmes
>>> <david.holmes at oracle.com>; serviceability-dev at openjdk.java.net
>>> Subject: Re: RFR(S) 8199924: Solaris: Correctly enqueue null 
>>> arguments of
>>> attach operations
>>>
>>> Hmmm... shouldn't the inconsistency in the Solaris backend also be
>>> addressed?
>>>
>>> Dan
>>>
>>>
>>> On 3/21/18 8:45 AM, Langer, Christoph wrote:
>>>> Hi David,
>>>>
>>>> thanks for looking at this. I currently have no emotions whether to 
>>>> fix it in C
>>> or in Java - I'll check it out...
>>>> Best regards
>>>> Christoph
>>>>
>>>>> -----Original Message-----
>>>>> From: David Holmes [mailto:david.holmes at oracle.com]
>>>>> Sent: Mittwoch, 21. März 2018 10:20
>>>>> To: Langer, Christoph <christoph.langer at sap.com>; serviceability-
>>>>> dev at openjdk.java.net
>>>>> Subject: Re: RFR(S) 8199924: Solaris: Correctly enqueue null 
>>>>> arguments of
>>>>> attach operations
>>>>>
>>>>> Hi Christoph,
>>>>>
>>>>> On 21/03/2018 6:10 PM, Langer, Christoph wrote:
>>>>>> Hi,
>>>>>>
>>>>>> may I please ask for reviews of the following small fix.
>>>>>>
>>>>>> Webrev: http://cr.openjdk.java.net/~clanger/webrevs/8199924.0/
>>>>>>
>>>>>> Bug: https://bugs.openjdk.java.net/browse/JDK-8199924
>>>>>>
>>>>>> If one passes null arguments to the varargs of attach operations, 
>>>>>> they
>>>>>> get swallowed on Solaris and following arguments will shift to lower
>>>>>> positions.
>>>>>>
>>>>>> Other platform implementations handle this correctly, for instance
>>>>>> linux:
>>>>>>
>>> http://hg.openjdk.java.net/jdk/jdk/file/f6ad4d73c834/src/jdk.attach/linux/cl 
>>>
>>>>> asses/sun/tools/attach/VirtualMachineImpl.java#l178
>>>>>
>>>>> Wouldn't it be simpler to just handle this at the Java level and
>>>>> substitute "" for null in the args array? We're only looking at a
>>>>> maximum of three possible entries.
>>>>>
>>>>> Thanks,
>>>>> David
>>>>>
>>>>>> Thanks
>>>>>>
>>>>>> Christoph
>>>>>>
>
>