Using the VM parameter -Djdk.tracePinnedThreads has a probability of causing the application to hang

[Alan Bateman]

On 03/08/2023 12:04, qia nxiao wrote:
> It appears to be a similar issue. However, I have a question: why is 
> there a high probability of reproducing deadlock when using the VM 
> parameter -Djdk.tracePinnedThreads, while it is difficult to reproduce 
> without using this VM parameter?
> This observation has also been confirmed in some of my practical 
> applications, where adding the parameter leads to deadlocks after a 
> few requests, while running without the parameter remains stable for a 
> long time.
>
Right, it's towards the end of the thread that I linked to. When 
-Djdk.tracePinnedThreads is set and a thread parks while pinned then it 
will attempt to print to System.out and so it also deadlocks. We need to 
fix this. In the mean-time, you can use the JFR event instead as it 
doesn't have to write to System.out.

-Alan