RFR (XXS) CR 8006997: ContendedPaddingWidth should be uintx

[David Holmes]

On 8/02/2013 8:39 PM, Aleksey Shipilev wrote:
> On 02/07/2013 12:55 PM, David Holmes wrote:
>> On 7/02/2013 5:52 PM, Aleksey Shipilev wrote:
>>> On 02/07/2013 03:43 AM, David Holmes wrote:
>>>> I have to wonder whether leaving ContendedPaddingWidth as signed is not
>>>> the simplest thing to do as it may be impractical, if not impossible, to
>>>> get uniformity of the signed-ness of expressions across all platforms.
>>>
>>> Well, Vladimir I. suggested we booby-trap against negative values with
>>> guarantee(...). Will that be sufficient?
>>
>> Sure - a number of flags get range checked.
>
> Ok then. This is the new webrev:
>   http://cr.openjdk.java.net/~shade/8006997/webrev.01/
>
> I haven't found another good place to stick the guarantee() to, so opted
> to stick it before the actual use. I would be happy to stick it
> somewhere else where the options are generally checked, but found no
> non-platform/non-OS specific location.

arguments.cpp - Arguments::parse_each_vm_init_arg - see 
-XX:MaxDirectMemorySize as an example.

Are there any other constraints on this value?

Thanks,
David


> Testing:
>    - Ad-hoc: fastdebug/release builds with negative value
>    - JPRT: full-cycle HotSpot testing
>
> -Aleksey.
>