RFR(S):8252629:jmap histo should accept "parallel" option without any specified value

[serguei.spitsyn at oracle.com]

Hi Lin,

I agree with David.
If I remember correctly, we already discussed this in the CSR for 
parallel flag and decided it should not be accepted without a value.

Thanks,
Serguei


On 9/1/20 16:51, David Holmes wrote:
> Hi Lin,
>
> On 1/09/2020 7:06 pm, linzang(臧琳) wrote:
>> Hi All,
>>
>>       Please help review this small change about jmap -histo:parallel
>>
>>       Bug: https://bugs.openjdk.java.net/browse/JDK-8252629
>>
>>       webrev: http://cr.openjdk.java.net/~lzang/8252629/webrev.00/
>>
>>       The problem is that "jmap -histo:parallel" command prompt error 
>> message "Fail: invalid option: 'parallel'.". Because "parallel=<N>" 
>> option is supported by specification, and "parallel=0" is defined as 
>> the default behavior. it is better to make "jmap -histo:parallel" 
>> behave same as the "jmap -histo:parallel=0". Please see description 
>> in the bug for more details.
>
> I don't agree that this is desirable. Is there any precedent for 
> accepting a flag this way and have it mean "use the default"? To me 
> this is a user error indicating that they don't understand what the 
> parallel flag means.
>
> David
> -----
>
>>       Moreover, does a CSR required for this issue? IMHO, it may not 
>> be necessary as specification already mention "parallel=0" is the 
>> default behavior. But it doesn't describe the exact behavior of 
>> "parallel without any specified value", may I ask your opinion about 
>> the CSR?
>>
>>
>> BRs,
>>
>> Lin
>>
>>