Sinatra stream + Redis PubSub

app.rb

require 'bundler'
Bundler.require

class App < Sinatra::Base
  # use Rack::FiberPool

  get '/' do
    # EM.run do
      # EM.synchrony do
        # redis = Redis.new(:host => "127.0.0.1", :port => 6379, :driver => :synchrony)
        # puts "connected"
        # puts redis.get("a")
        # puts "1connected"
    #     EM.stop
    #   end
    # end
    stream do |out|
      EM.synchrony do
        redis = Redis.new :driver => :synchrony
        puts "connected"
        puts redis.get("a")
        redis.psubscribe('*') do |on|
          on.psubscribe do |channel, subscriptions|
            puts "Subscribed to ##{channel} (#{subscriptions} subscriptions)"
          end

          on.pmessage do |pattern, channel, message|
            puts "#{channel}: #{message}"
            out << "#{channel}: #{message}"
          end

          on.punsubscribe do |channel, subscriptions|
            puts "UNsubscribed to ##{channel} (#{subscriptions} subscriptions)"
          end
        end
      end
    end
  end
end

Gemfile

source 'https://rubygems.org'

gem 'sinatra'
gem 'rack-fiber_pool', :require => 'rack/fiber_pool'

group :development do
  gem 'thin'
  gem 'pry-rails'
end

gem "redis", "~> 3.0"
gem "hiredis", "~> 0.4.5"
gem "redis-namespace"
gem "em-synchrony"

gistfile1.txt

[pirj@tp pubsub]$ thin start
>> Using rack adapter
>> Thin web server (v1.4.1 codename Chromeo)
>> Maximum connections set to 1024
>> Listening on 0.0.0.0:3000, CTRL+C to stop
connected
/home/pirj/.rvm/gems/ruby-1.9.3-p0/gems/redis-3.0.1/lib/redis/connection/synchrony.rb:73:in `resume': fiber called across threads (FiberError)
	from /home/pirj/.rvm/gems/ruby-1.9.3-p0/gems/redis-3.0.1/lib/redis/connection/synchrony.rb:73:in `block in connect'
	from /home/pirj/.rvm/gems/ruby-1.9.3-p0/gems/eventmachine-1.0.0.beta.4/lib/em/deferrable.rb:151:in `call'
	from /home/pirj/.rvm/gems/ruby-1.9.3-p0/gems/eventmachine-1.0.0.beta.4/lib/em/deferrable.rb:151:in `set_deferred_status'
	from /home/pirj/.rvm/gems/ruby-1.9.3-p0/gems/eventmachine-1.0.0.beta.4/lib/em/deferrable.rb:191:in `succeed'
	from /home/pirj/.rvm/gems/ruby-1.9.3-p0/gems/redis-3.0.1/lib/redis/connection/synchrony.rb:20:in `connection_completed'
	from /home/pirj/.rvm/gems/ruby-1.9.3-p0/gems/eventmachine-1.0.0.beta.4/lib/eventmachine.rb:179:in `run_machine'
	from /home/pirj/.rvm/gems/ruby-1.9.3-p0/gems/eventmachine-1.0.0.beta.4/lib/eventmachine.rb:179:in `run'
	from /home/pirj/.rvm/gems/ruby-1.9.3-p0/gems/thin-1.4.1/lib/thin/backends/base.rb:63:in `start'
	from /home/pirj/.rvm/gems/ruby-1.9.3-p0/gems/thin-1.4.1/lib/thin/server.rb:159:in `start'
	from /home/pirj/.rvm/gems/ruby-1.9.3-p0/gems/thin-1.4.1/lib/thin/controllers/controller.rb:86:in `start'
	from /home/pirj/.rvm/gems/ruby-1.9.3-p0/gems/thin-1.4.1/lib/thin/runner.rb:185:in `run_command'
	from /home/pirj/.rvm/gems/ruby-1.9.3-p0/gems/thin-1.4.1/lib/thin/runner.rb:151:in `run!'
	from /home/pirj/.rvm/gems/ruby-1.9.3-p0/gems/thin-1.4.1/bin/thin:6:in `<top (required)>'
	from /home/pirj/.rvm/gems/ruby-1.9.3-p0/bin/thin:19:in `load'
	from /home/pirj/.rvm/gems/ruby-1.9.3-p0/bin/thin:19:in `<main>'




[pirj@tp pubsub]$ thin start
>> Using rack adapter
>> Thin web server (v1.4.1 codename Chromeo)
>> Maximum connections set to 1024
>> Listening on 0.0.0.0:3000, CTRL+C to stop
connected
/home/pirj/.rvm/gems/ruby-1.9.3-p0/gems/redis-3.0.1/lib/redis/connection/synchrony.rb:76:in `yield': can't yield from root fiber (FiberError)
	from /home/pirj/.rvm/gems/ruby-1.9.3-p0/gems/redis-3.0.1/lib/redis/connection/synchrony.rb:76:in `connect'
	from /home/pirj/.rvm/gems/ruby-1.9.3-p0/gems/redis-3.0.1/lib/redis/client.rb:257:in `establish_connection'
	from /home/pirj/.rvm/gems/ruby-1.9.3-p0/gems/redis-3.0.1/lib/redis/client.rb:63:in `connect'
	from /home/pirj/.rvm/gems/ruby-1.9.3-p0/gems/redis-3.0.1/lib/redis/client.rb:276:in `ensure_connected'
	from /home/pirj/.rvm/gems/ruby-1.9.3-p0/gems/redis-3.0.1/lib/redis/client.rb:167:in `block in process'
	from /home/pirj/.rvm/gems/ruby-1.9.3-p0/gems/redis-3.0.1/lib/redis/client.rb:242:in `logging'
	from /home/pirj/.rvm/gems/ruby-1.9.3-p0/gems/redis-3.0.1/lib/redis/client.rb:166:in `process'
	from /home/pirj/.rvm/gems/ruby-1.9.3-p0/gems/redis-3.0.1/lib/redis/client.rb:78:in `call'
	from /home/pirj/.rvm/gems/ruby-1.9.3-p0/gems/redis-3.0.1/lib/redis.rb:714:in `block in get'
	from /home/pirj/.rvm/gems/ruby-1.9.3-p0/gems/redis-3.0.1/lib/redis.rb:36:in `block in synchronize'
	from /home/pirj/.rvm/rubies/ruby-1.9.3-p0/lib/ruby/1.9.1/monitor.rb:211:in `mon_synchronize'
	from /home/pirj/.rvm/gems/ruby-1.9.3-p0/gems/redis-3.0.1/lib/redis.rb:36:in `synchronize'
	from /home/pirj/.rvm/gems/ruby-1.9.3-p0/gems/redis-3.0.1/lib/redis.rb:713:in `get'
	from /home/pirj/source/switchcoder/pubsub/app.rb:21:in `block (2 levels) in <class:App>'
	from /home/pirj/.rvm/gems/ruby-1.9.3-p0/gems/sinatra-1.3.2/lib/sinatra/base.rb:296:in `block in stream'
	from /home/pirj/.rvm/gems/ruby-1.9.3-p0/gems/sinatra-1.3.2/lib/sinatra/base.rb:264:in `call'
	from /home/pirj/.rvm/gems/ruby-1.9.3-p0/gems/sinatra-1.3.2/lib/sinatra/base.rb:264:in `block in each'
	from /home/pirj/.rvm/gems/ruby-1.9.3-p0/gems/eventmachine-1.0.0.beta.4/lib/eventmachine.rb:1012:in `call'
	from /home/pirj/.rvm/gems/ruby-1.9.3-p0/gems/eventmachine-1.0.0.beta.4/lib/eventmachine.rb:1012:in `block in spawn_threadpool'