RFR: JDK-8163185: jhsdb jstack cannot work with normal mode

[Dmitry Samersoff]

Yasumasa,

I'm OK with this fix.

-Dmitry


On 2016-08-05 13:55, Yasumasa Suenaga wrote:
> Hi David,
> 
> Thank you for your comment.
> 
> For not to break current behavior, I think we should not change c'tor of
> JStack.
> I uploaded new webrev:
> 
>   http://cr.openjdk.java.net/~ysuenaga/JDK-8163185/webrev.01/
> 
> David, is it okay?
> Dmitry, could you review again?
> 
> 
> Thanks,
> 
> Yasumasa
> 
> 
> On 2016/08/05 14:49, David Holmes wrote:
>> On 5/08/2016 12:24 AM, Yasumasa Suenaga wrote:
>>> Hi all,
>>>
>>> This review request is related to [1].
>>>
>>> "jhsdb jstack" should work as normal mode without being added --mixed
>>> option.
>>> However, this command always works as mixed mode.
>>
>> So it seems to me the JStack class has a very poorly designed API and
>> command-line interface. It appears that jstack wants to default to
>> mixedMode and concurrentLocks, but provides no means to disable those
>> defaults. Given there is no way to turn those settings off from the
>> commad-line then the default should be that they are off! Then you
>> would not need current proposed change.
>>
>> That said the proposed fix effectively disables those defaults, which
>> seems to me to be a change in behaviour.
>>
>> I can't see a way to fix this without breaking existing behaviour
>> somewhere. In which case I would change the way the JStack instance is
>> initialized by default ie:
>>
>> public JStack() {
>>     this(true, true);
>> }
>>
>> becomes:
>>
>> public JStack() {
>>     this(false, false);
>> }
>>
>> Or it may be better to handle this on the jhsdb side and change this:
>>
>>        JStack.main(newArgs.toArray(new String[newArgs.size()]));
>> to
>>
>>        JStack js = new jstack(false,false);
>>        js.runWithArgs(newArgs.toArray(new String[newArgs.size()]));
>>
>>
>> Cheers,
>> David
>>
>>> So I uploaded webrev for this issue. Could you review it?
>>>
>>>   http://cr.openjdk.java.net/~ysuenaga/JDK-8163185/webrev.00/
>>>
>>>
>>> I'm jdk 9 reviewer (ysuenaga), but I cannot access JPRT.
>>> So I need a sponsor.
>>>
>>>
>>> Thanks,
>>>
>>> Yasumasa
>>>
>>>
>>> [1]
>>> http://mail.openjdk.java.net/pipermail/serviceability-dev/2016-August/020087.html
>>>
>>>


-- 
Dmitry Samersoff
Oracle Java development team, Saint Petersburg, Russia
* I would love to change the world, but they won't give me the sources.