Work-in-progress: 8236485: Epoch synchronization protocol for G1 concurrent refinement

Man Cao manc at
Sun Dec 22 16:50:14 UTC 2019

Hi all,

I have written up a description and challenges for implementing an epoch
synchronization protocol. This protocol is necessary for removing the
StoreLoad fence in G1's post-write barrier (JDK-8226731)

Work-in-progress webrev:

There are two main challenges that I'm not sure how to resolve:
- Triggering a thread-local handshake is a blocking operation that can pass
a safepoint.
- There are native post-write barriers executed by threads in native/VM

Discussions and suggestions are highly appreciated!


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