> 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
Roman Kennke has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains two additional commits since the last revision: - Merge branch 'master' into JDK-8256106 - 8256106: Bypass intrinsic/barrier when calling Reference.get() from Finalizer ------------- Changes: - all: https://git.openjdk.java.net/jdk/pull/1140/files - new: https://git.openjdk.java.net/jdk/pull/1140/files/52820f98..61878147 Webrevs: - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=1140&range=01 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=1140&range=00-01 Stats: 5646 lines in 150 files changed: 3822 ins; 862 del; 962 mod Patch: https://git.openjdk.java.net/jdk/pull/1140.diff Fetch: git fetch https://git.openjdk.java.net/jdk pull/1140/head:pull/1140 PR: https://git.openjdk.java.net/jdk/pull/1140
