Read this blog post: SyncEm: Thread-Safe Decorators in Ruby.

Sometimes you have an object that is not thread-safe, but you need to make sure each of its methods is thread-safe, because they deal with some resources, like files or databases and you want them to manage those resources sequentially. This small gem will help you achieve exactly that without any re-design of the objects you already have. Just decorate them with SyncEm thread-safe decorator and that is it.

First, install it:

$ gem install syncem

Then, use it like this:

require 'syncem'
obj = SyncEm.new(obj)

That's it.

Read these guidelines. Make sure you build is green before you contribute your pull request. You will need to have Ruby 2.3+ and Bundler installed. Then:

$ bundle update
$ bundle exec rake

If it's clean and you don't see any error messages, submit your pull request.