Experiencing an issue with ScheduledExecutorService alongside VT

[Alan Bateman]

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