RFR Backport: 8166583: Add oopDesc::klass_or_null_acquire()

Tue Nov 3 07:17:28 UTC 2020

Hi,

As mentioned in [1], JDK-8160369 have not been backported to JDK8u. This is necessary for RMO architectures like aarch64.

JDK- 8166583 is a subtask of JDK-8160369.
Original bug: https://bugs.openjdk.java.net/browse/JDK-8166583
Original patch: http://hg.openjdk.java.net/jdk9/jdk9/hotspot/rev/f71f1d9a2e26

The original patch for JDK-8166583 does not apply cleanly to jdk8u-dev due to path and code refactoring work in jdk9+.

Webrev for 8u:
    http://cr.openjdk.java.net/~fyang/8166583-8u/webrev.00/

Performed full jtreg test with release build both on aarch64-linux and x86_64-linux platforms.

OK to backport?

Thanks,
Felix

[1] https://mail.openjdk.java.net/pipermail/hotspot-gc-dev/2020-July/030313.html