Should AbstractInterruptibleChannel.close() still use a synchronized block?

[Alan Bateman]

On 18/10/2023 14:03, Mark Rotteveel wrote:
> Prompted by this Stack Overflow question 
> [https://stackoverflow.com/q/77315894/466862], I'm wondering if the 
> use of a synchronized block in AbstractInterruptibleChannel.close() 
> as-of Java 21 is correct, and shouldn't be replaced with a 
> ReentrantLock or something else.
>
> As shown in the question, closing of a channel derived from 
> AbstractInterruptibleChannel can cause pinning of virtual threads.

We decided it wasn't worth doing because it's rare to set SO_LINGER. 
Temporary pinning due to contention on the readLock or writeLock when 
closing is okay.

In the mean-time, we are working to remove restriction on synchronized 
blocks. We hope to have something in the loom repo soon.

-Alan