G1 Garbage collector to appear in 1.6

[Barry]

Hi all,

According to ThePlanetarium the G1 collector will be available both in Java 7 and the latest Java 1.6 (14) releases.

Summary of G1 (http://tech.puredanger.com/2008/05/09/javaone-g1-garbage-collector)


G1 (”garbage first”) takes a different approach - all memory (except perm gen) is broken into 1 MB “regions”. Young and old are both comprised of some set of non-contiguous regions but these change over time. During young gc survivors of a region are either copied to a new young gen region or to an old gen region as appropriate.

In G1, the old generation GC there is one stop-the-world pause to mark. If any region is found to contain no live objects, the region is immediately reclaimed (this happens more frequently than you’d expect due to locality). Then compact old regions into new old region. Old gen collections are piggybacked on young gen collections.


The article claiming the release in 1.6.0_14 is: https://jdk6.dev.java.net/6uNea.html

[kjkoster]

WANT!

G1 is so cool. Totally 2009.

I heard and read about it and it will make a huge difference for large Java installations. If this is true, 1.6.0_14 is a mandatory update before any other detailed GC tuning.

Kees Jan

[geekroom]

G1 makes the application a lot more agile: the latancy of the application will raise - the app can be named as "soft-real-time". This is done by replacing two kinds of GC runs (small minor ones and one big on Tenured Gen) to equal-sized small ones.

For more details look at this: http://geekroom.de/java/java-expertise-g1-fur-java-7/