Incorrect arguments is passed to sun.misc.Perf#createLong (original) (raw)

Mandy Chung mandy.chung at oracle.com
Wed Apr 10 21:10:15 UTC 2013

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.

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# to Perf#createLong .

Indeed - it's a bug that calls Perf.createLong with the incorrect parameters. I have filed a bug (8011934).

Have you signed the OCA [1]?

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, UNone, 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, UNone, 0L); ---------

I've applied a patch which is attached in this email, it's works fine. Thanks, Yasumasa

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