Experiencing an issue with ScheduledExecutorService alongside VT

[Yuval Lombard]

Hi Alan

Thanks for replying!

When the issue occurs the Log you mentioned is not being printed - it is as
if (or maybe it is even what is really happening) the virtual thread is not
being scheduled (by its internal scheduler)
I to a thread dump by executing "kill -3 <pid>" and did not see the VT,
will  `java <pid> Thread.dump_to_file <file>` produce a more detailed view
of the living threads?

I will try to run the later EA build

On Sun, 21 Jul 2024 at 11:14, Alan Bateman <Alan.Bateman at oracle.com> wrote:

> On 21/07/2024 08:05, Yuval Lombard wrote:
> > Hey team
> >
> > We are experiencing some weird halting issues when scheduling tasks
> > with ScheduledExecutorService and VT.
> >
> > We are observing some near deadlock issues / halting of executors
> > which we are not able to reproduce when using platform threads
> >
> > This is one example of a near deadlock situation, where for some
> > reason virtual threads are starting to execute a task, and not
> > reaching the finally block nor the catch Throwable block to release
> > the acquired semaphore permit, reaching to drained semaphore.
>
>
> Is "Scheduling .. task for device" logged? Did you take thread dump with
> `java <pid> Thread.dump_to_file <file>` and try to identify the virtual
> thread?
>
> One of the later mails mentions 23-loom+4-102 and not seeing JFR events.
> Can you re-run with the latest EA build (currently 24-loom+2-24) as that
> has changes for the JFR events that may provide some insight here.
>
> -Alan
>


-- 

Kind regards,

*Yuval Lombard*

*Lead Software Engineer*

+972.50.548.0111

yuval.l at securithings.com

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