JDK-8334085: Cannot reproduce failing test

[Iñigo Mediavilla]

Hello Serguei,

Thanks a lot for sharing the update and for solving the issue. Do you think
that you could help me understand exactly what's happening ?

Based on the DBG output shared in JBS, my understanding is that what
happens in the test is the following:

Main                         Thread
-------------------------   ----------------------------
1. acquire java lock
2. starting thread
                                 3. jni call
                                 4. MonitorContendedEnter
5. release java lock
                                 6. acquire java lock
                                 7. MonitorContendedEntered
                                 8. Thread in sync section
                                 9. release java lock
                               10. why freeze doesn't pin ?

What I'm struggling to understand is why after the thread releases the java
lock, the virtual thread is still frozen, and specially why does it freeze
while holding a jni monitor ? I've run tests locally trying to freeze a
virtual thread holding a JNI lock and my virtual threads are always being
pinned to the carrier with reason ("holding a lock").

Thanks in advance

Íñigo

On Fri, Jul 19, 2024 at 10:41 PM Serguei Spitsyn <serguei.spitsyn at oracle.com>
wrote:

> Hi Iñigo,
>
> Patricio helped to reproduce this issue and also identified the problem
> (please, see in the bug report).
> The fix is a one-liner. I’ll post a PR after some mach5 testing.
>
> Thank you for involvement into this issue!
>
> Thanks,
>
> Serguei
>
>
>
> *From: *Iñigo Mediavilla <imediava at gmail.com>
> *Date: *Saturday, July 13, 2024 at 12:08 AM
> *To: *Chris Plummer <chris.plummer at oracle.com>
> *Cc: *dholmes at openjdk.org <dholmes at openjdk.org>, loom-dev at openjdk.org <
> loom-dev at openjdk.org>, sspitsyn at openjdk.org <sspitsyn at openjdk.org>
> *Subject: *Re: JDK-8334085: Cannot reproduce failing test
>
> I see, in that case Serguei would you want to still own this JBS or would
> you be OK if I try to have a look at it ?
>
>
>
> Iñigo
>
> El vie, 12 jul 2024, 19:11, Chris Plummer <chris.plummer at oracle.com>
> escribió:
>
> Failures are very intermittent. We last saw a failure in our CI testing
> on 2024-07-03. What command are you using to run the test?
>
> Chris
>
> On 7/12/24 2:34 AM, Iñigo Mediavilla wrote:
> > Hello,
> >
> > While looking at possible JBS tickets to work on, I saw JDK-8334085
> > where an assertion was reported to be failing for the
> > GetOwnedMonitorInfoTest. Before I even asked around to wonder if this
> > issue was already being looked at, I tried to reproduce the failure
> > locally, but I don't manage to make the test fail. Is this still an
> > issue in JDK-24 ? David can you still reproduce the failing test ?
> >
> > Best
> >
> > Íñigo Mediavilla Saiz
> >
> >
>
>
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