Are there any liveness issues about thread scheduling in the JVM?

[David Holmes]

On 16/07/2012 12:20 PM, Krystal Mok wrote:
> This is actually the source of my earlier mail "Multiple Java threads
> seem to have locked the same object monitor from the thread dumps" [1].
> Apparently Xiaodong didn't subscribe to the mailing list before sending
> his mail to hotspot-dev, and while waiting for moderator approval he
> sent another mail directly to me...

I didn't see any mention in here of the same object claiming to be 
locked, so I didn't connect them.

David
-----

> - Kris
>
> [1]:
> http://mail.openjdk.java.net/pipermail/hotspot-runtime-dev/2012-July/004106.html
>
> On Mon, Jul 16, 2012 at 8:55 AM, David Holmes <david.holmes at oracle.com
> <mailto:david.holmes at oracle.com>> wrote:
>
>     On 10/07/2012 9:20 PM, Xie Xiaodong wrote:
>
>
>         We are facing some interesting behavior in production.
>
>     <snip>
>
>         Here are some thread dumps taken at different time. During this
>         period,
>         only httpSSLWorkerThread-10080-99 can make progress. Other
>         threads were
>         always stuck in the synchronization point. And "waiting to lock
>         <0x75b395d8>", this hex number changed several times. What does
>         this number
>         mean?
>
>
>     An example:
>
>     - waiting to lock <0x75b395d8> (a casinomodule.util.__TimeUtilImpl)
>
>     The number is the address of an object that the threads are trying
>     to lock. It is an instance of casinomodule.util.__TimeUtilImpl. If
>     the address, for a given thread, keeps changing, it means that the
>     threads are in fact making progress, as they must have locked object
>     form the previous stack dump and then moved on to the current one.
>     If the number is different for different threads then they are
>     simply trying to lock different objects.
>
>     There would appears to be a synchronization bottleneck in this
>     "casinomodule"
>
>     David
>     -----
>
>
>         Thanks a lot for your time.
>
>
>
>