JRuby 9.1.0.0 Release Notes

IN PROGRESS

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

• Java stack-trace filtering was tuned to not exclude everything under the org.jruby package prefix, we still avoid the additional noise from the stack-trace but no longer filter potentially unknown packages (e.g. org.jruby.rack) or extension stacks (org.jruby.ext). This change also affects backtrace information on the Ruby side which might now include more .java parts.

• the internal JavaPackageModuleTemplate has been refactored into a standalone module-like class, all package stubs org.kares.jruby now return a JavaPackage instance (which is a Module)

• names throw and catch are no longer allowed as package names using the method format (org.jruby.catch will now dispatch to Kernel.catch) - those are not valid Java package names anyways

• singleton_class (as well as hook methods such as singleton_method_added, singleton_method_removed) is no longer allowed as a package-name using the method ('.') format (org.jruby.singleton_class will return the Ruby meta-class)

• pkg.to_s now returns package-name opposed to "module name" e.g. java.lang.to_s == 'java.lang' (note that inspect still behaves the same as before: java.lang.inspect == 'Java::JavaLang')

• improved java.util.Map equality (==, eql?) to other map/hash instances - previously wasn't 100% correct

• java.util.Map proxies now support all of Hash methods (including new ones such as dig, fetch_values and comparison operators e.g. <=)

• Java arrays now handle value equality == with Ruby arrays (use eql? if types need to match as well). this also affects === with native arrays.

• Java's exception hierarchy java.lang.Throwable no longer provides a to_str method, we feel like this unintentionally slipped probably due misunderstanding the difference between Ruby's to_s and to_str

• java.util.Collection instances are no longer to_ary (Array-like) convertible, please note that to_a still exists and (for compatibility) java.util.List provides to_ary as well.

• 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.

• jrubyc --jdk5 and -5 switches were removed (Java 5 has not been supported for a while)

• jrubyc --dir option now handles absolute paths correctly with the --target option

Issues/Features Resolved in 9.1.0.0