Accurate CPU timing on Windows -- How?

We've done a good amount of JMX instrumentation of our application -- including various embedded timing metrics, both wall clock and CPU times.

The issue we're seeing is that at least on Windows the CPU thread times produced by ThreadMXBean.getCurrentThreadCpuTime() are horribly inaccurate.  We attempt to time various relatively short-lived requests and they all give an elapsed CPU time of 0.  I can see that granularity in the timer might lead to some of this, but we have many such requests and they all show an elapsed time of 0 -- whereas one would expect that granularity would lead to sudden large timer jumps during in some measurement intervals.

• Is this a known issue?
• Are there plans to address this?
• Have others worked around this?

Overall, the results are bad enough that we're starting to consider dropping use of ThreadMXBean in favor of JNI code on some platforms (structured such that if the JNI stuff can't be loaded we fallback to using ThreadMXBean, of course).  I'd really like to hope that either this is being addressed in an upcoming Java update or that at least someone else has recognized the issue and that there is freely available JNI stuff to use.

--
Jess Holle

P.S. I have noticed other substantial issues in this area as well, including:

• On Windows [at least], System.currentTimeMillis()'s resolution is not milliseconds but rather about 0.01 seconds.
• We could use System.nanoTime() instead, but it appears that acquiring this takes a bit more time.  Moreover, for the usages in question millisecond accuracy is sufficient, but 0.01 seconds is not always.
• There is no more efficient way to get at the Sun-specific OS MBean attribute, "ProcessCpuTime", than

PLATFORM_MBEAN_SERVER.getAttribute( OS_MBEAN_NAME, "ProcessCpuTime" )

which is not very efficient at all.

• It would be nice if the implementation class was public so one could look up the method via reflection at static init time and then directly invoke the method object.

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