Incorrect arguments is passed to sun.misc.Perf#createLong

[Yasu]

Hi Mandy,

On 4:59, Mandy Chung wrote:
> Hi Yasumasa,
>
> I'm adding core-libs and bcc serviceability-dev to move this thread to core-libs for sun.misc.PerfCounter discussion.
>
> On 4/9/2013 4:50 AM, Yasu wrote:
>> Hi,
>>
>> I'm trying to create entry from Java program to hsperfdata through sun.misc.PerfCounter .
>
> First of all, sun.misc.PerfCounter is a private API that is not supported and may be changed and removed in any future release. I'm curious how you create a counter in hsperfdata through sun.misc.PerfCounter. The constructor is private.

I've understood that sun.* packages is private API.
I use PerfCounter with reflection API ( setAccessible(true) )  .


>> However, I cannot watch the updated value in my entry through the jstat with interval option.
>>
>> I guess this cause is that wrong arguments are passed from PerfCounter#<init> to Perf#createLong .
>>
>
> Indeed - it's a bug that calls Perf.createLong with the incorrect parameters. I have filed a bug (8011934).

Thanks!


> Have you signed the OCA [1]?

Yes.
I already sent OCA with my signature.


Thanks,

Yasumasa

> Thanks
> Mandy
> [1] http://openjdk.java.net/contribute/
>
>> sun.misc.PerfCounter:
>> ---------
>> private PerfCounter(String name, int type) {
>> this.name = name;
>> ByteBuffer bb = perf.createLong(name, U_None, type, 0L);
>> bb.order(ByteOrder.nativeOrder());
>> this.lb = bb.asLongBuffer();
>> }
>> ---------
>>
>> sun.misc.Perf:
>> ---------
>> public native ByteBuffer createLong(String name, int variability,
>> int units, long value);
>> ---------
>>
>> "type" in constructor of PerfCounter means "variability".
>> So "type" should be set to 2nd argument in perf.createLong()
>>
>> perf.createLong() should be called as following:
>> ---------
>> ByteBuffer bb = perf.createLong(name, type, U_None, 0L);
>> ---------
>>
>>
>> I've applied a patch which is attached in this email, it's works fine.
>>
>>
>> Thanks,
>>
>> Yasumasa