On Fri, 12 Jul 2024 10:22:42 GMT, Aleksey Shipilev <sh...@openjdk.org> wrote:
> > The reason we did not do this before is that this is not a strong reference > > store. Strong reference stores with a SATB collector will keep the referent > > alive, which is typically the exact opposite of what a user wants when they > > clear a Reference. > > You mean not doing this store just on the Java side? Yes, I agree, it would > be awkward. In intrinsic, we are storing with the same decorators that > `JVM_ReferenceClear` is using, which should be good with SATB collectors. > Perhaps I am misunderstanding the comment. The runtime use of the Access API knows how to resolve an unknown oop ref strength using AccessBarrierSupport::resolve_unknown_oop_ref_strength. However, we do not have support for that in the C2 backend. In fact, it does not understand non-strong oop stores at all. Because there hasn't really been a use case for it, other than clearing a Reference. That's the precise reason why we do not have a clear intrinsic; it would have to add that infrastructure. ------------- PR Comment: https://git.openjdk.org/jdk/pull/20139#issuecomment-2225430174
