A shim to define Ractor by using Thread, Queue, etc if Ractor is not already defined.

This is notably useful to run programs relying on Ractor on Ruby implementations which don't define Ractor such as TruffleRuby and JRuby.

Note that TruffleRuby and JRuby both run Ruby code in threads in parallel, so this gem enables using the Ractor API on these Rubies and run Ractors in parallel.

The gem also provides the Ruby 4.0 Ractor API (Ractor::Port, Ractor#{join,value,monitor}, etc) for CRuby 2.7 to 3.4.

When Ractor is not already defined, this gem implements Ractor.make_shareable(object) by just returning object to avoid unnecessary overhead. The main reason is that the CRuby implementation of Ractor.make_shareable returns an immutable object, so it won't be mutated by the program anyway and there is no need to deep freeze. Another reason is many gems do Ractor.make_shareable(object) if defined?(Ractor) and so that becomes dependent on whether Ractor is defined before that gem loads. That problem disappears if Ractor.make_shareable(object) is noop.

$ gem install ractor-shim

or

# In Gemfile
gem "ractor-shim"

require 'ractor/shim'

Ractor.new { ... }

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in ractor-shim.gemspec, and then run bundle exec rake release, which will create a git tag for the version, push git commits and the created tag, and push the .gem file to rubygems.org.

Bug reports and pull requests are welcome on GitHub at https://github.com/eregon/ractor-shim.

The gem is available as open source under the terms of the MIT License.