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

[Yasumasa Suenaga]

Hi David,

> It is a better fix in my opinion but still changes the behaviour of jhsdb - or is that not an issue? Is jhsdb new with 9?

Can I list you as a reviewer?
This change is agreed by Dmitry. So I think we can move forward it.


Thanks,

Yasumasa


On 2016/08/05 20:38, David Holmes wrote:
> On 5/08/2016 8:55 PM, 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?
>
> It is a better fix in my opinion but still changes the behaviour of jhsdb - or is that not an issue? Is jhsdb new with 9?
>
> Thanks,
> David
>
>> 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
>>>>
>>>>