Avoid synchronized block or methods

[reda-alaoui]

According to https://docs.oracle.com/en/java/javase/21/core/virtual-threads.html#GUID-04C03FFC-066D-4857-85B9-E5A27A875AF9:

A current limitation of the implementation of virtual threads is that performing a blocking operation while inside a synchronized block or method causes the JDK's virtual thread scheduler to block a precious OS thread, whereas it wouldn't if the blocking operation were done outside of a synchronized block or method. We call that situation "pinning".

IMHO, all synchronizd blocks or methods should be replaced with ReentrantLock usage.

[He-Pin]

Not all, only io bound I think.

[pivovarit]

This is a temporary limitation of Virtual Threads and applies only to blocking operations inside synchronized blocks. I went through all cases of synchronized, and only deprecated-for-removal Lazy can run blocking code inside it, and that's the only change needed here I believe

[KrnSaurabh]

Hi @pivovarit, I would be happy to contribute. Please let me know if I can pick this up if not assigned to someone already?

[pivovarit]

Sure, it’s yours :)

[KrnSaurabh]

@pivovarit I have created a PR for review - #2842

[pivovarit]

Looks done to me :)