FiberHook

With this gem you can hook into fiber creation to pass a value from the parent fiber to the child fiber.

This is useful when you’ve got thread-local storage (which is actually fiber-local) that you want also accessible from within child fibers. It works without requiring that fibers go through your own fiber-creation method, so that even fibers created inside gems you don't own will work as expected.

A potential use case is using the Async gem with the Falcon server and you want to use RequestStore for per-request storage. For this particular use case, take a look at the request_store-fibers gem.

Add this line to your application's Gemfile:

gem 'fiber_hook'

And then execute:

$ bundle install

Or install it yourself as:

$ gem install fiber_hook

In this example you’re passing a thread-local :request_store value from parent fiber to child fiber. They're sharing the same object in memory but there's no risk of a race condition because these are fibers, not threads.

# `new` is a Proc that returns a value in the parent fiber context.
# `resume` is a Proc that takes that value as a param and runs
#   in the child fiber context.
Fiber.hook(
  new: -> { Thread.current[:request_store] },
  resume: ->(value) { Thread.current[:request_store] = value }
)

Need to remove a hook? Call Fiber.unhook:

hook_id = Fiber.hook(...)
...
Fiber.unhook(hook_id)

After checking out the repo, run bin/setup to install dependencies. Then, run rake spec to run the tests. You can also run bin/console for an interactive prompt that will allow you to experiment.

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, 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/BMorearty/fiber_hook.

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