CFV: New project: Shenandoah

Roman Kennke roman at
Thu Sep 10 12:06:29 UTC 2015

Project Shenandoah:  An Ultra-low Pause time GC for OpenJDK


I hereby propose the creation of the Shenandoah project with Christine
H. Flood as the initial lead and the Hotspot group as the sponsoring
group. [1]

Shenandoah is an ultra-low pause time garbage collector that reduces GC
pause times by performing more garbage collection work concurrently
with the running Java program. CMS and G1 both perform concurrent
marking of live objects.  Shenandoah adds concurrent compaction.

Shenandoah has so far been developed as part of the IcedTea project:

It has usable implementations for OpenJDK9 and OpenJDK8.

Initial authors/reviewers:
Christine Flood (cflood at
Roman Kennke (rkennke at

Christine H. Flood is a Principal Software Engineer at Red Hat.  
She has a long history of implementing garbage collected programming
languages at MIT, Symbolics, Sun Labs, and now Red Hat.  She helped 
develop both G1 and the parallel collector.  A garbage collector 
with concurrent evacuation is the obvious next step.

Roman Kennke is Principle Software Engineer at Red Hat, working on
Shenandoah since two years now. Before this, he worked on Thermostat,
and contributed to OpenJDK in several areas, most importantly the Zero
and Shark ports, graphics, and ports to embedded platforms.

Votes are due by Sept, 24th, 2015

Only current OpenJDK Members [2] are eligible to vote on this 
motion.  Votes must be cast in the open on the discuss list.
Replying to this message is sufficient if your mail program
honors the Reply-To header.

For Lazy Consensus voting instructions, see [3].

Best regards,
Roman Kennke


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