On Tue, 10 Nov 2020 09:37:29 GMT, Roman Kennke <rken...@openjdk.org> wrote:
> Finalizer calls Reference.get() from the Finalizer to acquire the finalizee. > Concurrent reference processing GCs like Shenandoah and ZGC would return NULL > for unreachable referents, and thus would not call finalize() on them. > > ZGC works around this by fixing the referent before enqueuing, so that the > barrier would take the fast-path, but Shenandoah cannot do this. > > It is ok to bypass the barrier altogether in this place, because the > FinalReference is inactive and marking and reference-discovery treat inactive > FinalReferences like strong references. > > Testing: > - [x] hotspot_gc_shenandoah > - [x] tier1 +UseShenandoahGC +ShenandoahVerify > - [x] tier2 +UseShenandoahGC +ShenandoahVerify > - [x] tier1 > - [x] tier2 This pull request has now been integrated. Changeset: 96e02610 Author: Roman Kennke <rken...@openjdk.org> URL: https://git.openjdk.java.net/jdk/commit/96e02610 Stats: 15 lines in 2 files changed: 14 ins; 0 del; 1 mod 8256106: Bypass intrinsic/barrier when calling Reference.get() from Finalizer Reviewed-by: eosterlund ------------- PR: https://git.openjdk.java.net/jdk/pull/1140
