Merge pull request #23152 from matthewd/actioncable-concurrent

Eliminate the EventMachine dependency

1 files changed, 16 insertions, 0 deletions

diff --git a/actioncable/lib/action_cable/subscription_adapter/redis.rb b/actioncable/lib/action_cable/subscription_adapter/redis.rb
index 3b86354621..a035e3988d 100644
--- a/actioncable/lib/action_cable/subscription_adapter/redis.rb
+++ b/actioncable/lib/action_cable/subscription_adapter/redis.rb
@@ -1,11 +1,18 @@
+require 'thread'
+
 gem 'em-hiredis', '~> 0.3.0'
 gem 'redis', '~> 3.0'
 require 'em-hiredis'
 require 'redis'
 
+EventMachine.epoll  if EventMachine.epoll?
+EventMachine.kqueue if EventMachine.kqueue?
+
 module ActionCable
   module SubscriptionAdapter
     class Redis < Base # :nodoc:
+      @@mutex = Mutex.new
+
       def broadcast(channel, payload)
         redis_connection_for_broadcasts.publish(channel, payload)
       end
@@ -27,6 +34,7 @@ module ActionCable
 
       private
         def redis_connection_for_subscriptions
+          ensure_reactor_running
           @redis_connection_for_subscriptions ||= EM::Hiredis.connect(@server.config.cable[:url]).tap do |redis|
             redis.on(:reconnect_failed) do
               @logger.info "[ActionCable] Redis reconnect failed."
@@ -37,6 +45,14 @@ module ActionCable
         def redis_connection_for_broadcasts
           @redis_connection_for_broadcasts ||= ::Redis.new(@server.config.cable)
         end
+
+        def ensure_reactor_running
+          return if EventMachine.reactor_running?
+          @@mutex.synchronize do
+            Thread.new { EventMachine.run } unless EventMachine.reactor_running?
+            Thread.pass until EventMachine.reactor_running?
+          end
+        end
     end
   end
 end