Question about pinned

[Alan Bateman]

On 18/09/2023 06:48, qia nxiao wrote:
> Hello everyone,
>
> Recently, my application experienced a deadlock issue due to "pinned" 
> reasons. It was difficult to detect during testing because it occurred 
> within exception handling logic.The occurrence of "pinned" situations 
> has become the biggest issue for me when using virtual threads.
>
> The official documentation mentions the possibility of "pinned" 
> situations. I would like to ask what the root cause of the "pinned" 
> issue is in synchronized blocks or methods? Will there be a solution 
> in the upcoming JDK 21 or is it already being planned for resolution?

The issue of pinning is described in JEP 444 [1], along with diagnostics 
that can help identify some of these cases.

There is work underway to re-implement monitors in the longer term. For 
the shorter term, there is another effort under way to allow the carrier 
be released when blocking at monitor enter. No time frame / dates right 
not but not JDK 21 as that release is at GA.

-Alan

[1] https://openjdk.org/jeps/444