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

[David Holmes]

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
> 
>