Thread with access to a shared Request Context

thread_with_context.rb

# Public: Module that overrides Thread initialization to preserve the request context.
module ThreadWithContext

  # Public: Returns a new Thread that preserves the context of the current request.
  def new(*args)
    request_id = Thread.current[:request_id]
    super(*args) {
      Thread.current[:request_id] = request_id
      yield *args
    }
  end
end

# Use at your own peril, when you modify stdlib classes many things can go wrong :)
Thread.class_eval do
  class << self
    prepend ThreadWithContext
  end
end

Prepend and forget? 😄

Awesome, thanks a lot man 👍 Just a note about Fibers - Thread.current[] storage is Fiber-local, see e.g. http://www.virtuouscode.com/2012/02/02/ruby-thread-locals-are-also-fiber-local/ . Since the current implementation of request_store_rails relies on Thread.current[], the request_id needs to be propagated to new Fibers as well as new Threads in this "prepend and forget" gist.

Alternatively, Thread.current[] can be changed to Thread-scoped Thread#thread_variable_set/get, both in this gist and the gem impl.