JRuby 9.1.0.0 Release Notes

JRuby 9000 is the new major version of JRuby, representing years of effort and large-scale reboots of several JRuby subsystems.

Major features of JRuby 9000:

• Ruby 2.3 compatibility, minus features listed below https://github.com/jruby/jruby/issues/3479
• A new optimizing runtime based on a traditional compiler design
• New POSIX-friendly IO and Process
• Fully ported encoding/transcoding logic from MRI

JRuby 9.1.0.0

Notable changes since 9.0.5.0

• removing default -Xmx (500MB) setting from jruby.bash. Most users that get JRuby will end up using the bash script. https://github.com/jruby/jruby/issues/3739

• Thread.new and others spawning threads (Fiber, Enumerator) should be a bit faster to start, most importantly they no longer possibly slow-down due low entropy sources on *nix systems due a Java SecureRandom instantiation on JRuby's ThreadContext. https://github.com/jruby/jruby/pull/3723

Java Integration

• Warbler has had issues with pre-compiled .rb files due broken IR de-serialization logic, we expect all issues to be fixed and added specs to cover previously failing issues.

Issues/Features Resolved in 9.1.0.0