Bug ID: JDK-8250784 Shenandoah: A Low-Pause-Time Garbage Collector

Type: New Feature
Component: hotspot
Sub-Component: gc
Affected Version: 11

Priority: P3
Status: Resolved
Resolution: Fixed
OS: generic
CPU: x86,x86_64,aarch64
Fix Versions: 11.0.9

Submitted: 2020-07-29
Updated: 2021-08-20
Resolved: 2020-07-29

This is a backport of the Shenandoah garbage collector for JDK11. It backports roughly the Shenandoah GC from JDK15. See the original JEP 189:

https://bugs.openjdk.java.net/browse/JDK-8046179

What is backported is - for the most part - the Shenandoah implementation as it is present at this revision:
http://hg.openjdk.java.net/jdk/jdk/rev/b324ae69f933

URL: https://hg.openjdk.java.net/jdk-updates/jdk11u/rev/959d0caa9b7d User: clanger Date: 2020-08-05 05:22:14 +0000
05-08-2020
URL: https://hg.openjdk.java.net/jdk-updates/jdk11u-dev/rev/959d0caa9b7d User: rkennke Date: 2020-07-29 17:38:33 +0000
29-07-2020
Approving on the grounds that it should do no harm for users not wanting to build with shenandoah.
29-07-2020
Fix-request (11u): Backports Shenandoah GC to 11u. Review-threads: https://mail.openjdk.java.net/pipermail/jdk-updates-dev/2020-July/003472.html and a lot of relevant discussion: https://mail.openjdk.java.net/pipermail/jdk-updates-dev/2020-June/003368.html
29-07-2020
Approval from the OpenJDK 11u stream lead of the jdk-updates project: https://mail.openjdk.java.net/pipermail/jdk-updates-dev/2020-July/003561.html
29-07-2020

Relates :	JDK-8272772 - Shenandoah: compiler/c2/aarch64/TestVolatilesShenandoah.java fails in 11u
Relates :	JDK-8251354 - Shenandoah: Fix JFR test failures
Relates :	JDK-8214259 - Implementation: JEP 189: Shenandoah: A Low-Pause-Time Garbage Collector (Experimental)
Relates :	JDK-8251161 - Apply copyright header changes of JDK-8237182 to Shenandoah files in OpenJDK 11
Relates :	JDK-8250888 - nsk/jvmti/scenarios/general_functions/GF08/gf08t001/TestDriver.java fails