The JVM itself doesn't implement this feature, but something similar is used by some Ruby and Python applications: http://old.blog.phusion.nl/2013/01/22/phusion

The JVM itself doesn't implement this feature, but something similar is used by some Ruby and Python applications: http://old.blog.phusion.nl/2013/01/22/phusion-passenger-4-technology-preview-out-of-band-work/ http://old.blog.phusion.nl/2013/01/22/phusion-passenger-4-te... > Normally the garbage collector fires up as soon as the Ruby interpreter thinks it needs to, which possibly results in hundreds of milliseconds of latency. With the Out-of-Band Work feature, you can run the garbage collector outside the request cycles so that garbage collection runs inside cycles are much less expensive.