Run a single eventmachine timer to send heartbeats

2 files changed, 12 insertions, 0 deletions

diff --git a/lib/action_cable/server/base.rb b/lib/action_cable/server/base.rb
index 43849928b9..9315a48f20 100644
--- a/lib/action_cable/server/base.rb
+++ b/lib/action_cable/server/base.rb
@@ -18,6 +18,7 @@ module ActionCable
 
       # Called by rack to setup the server.
       def call(env)
+        setup_heartbeat_timer
         config.connection_class.new(self, env).process
       end
 
diff --git a/lib/action_cable/server/connections.rb b/lib/action_cable/server/connections.rb
index 15d7c3c8c7..455ff1ab29 100644
--- a/lib/action_cable/server/connections.rb
+++ b/lib/action_cable/server/connections.rb
@@ -4,6 +4,8 @@ module ActionCable
     # you can't use this collection as an full list of all the connections established against your application. Use RemoteConnections for that.
     # As such, this is primarily for internal use.
     module Connections
+      BEAT_INTERVAL = 3
+
       def connections
         @connections ||= []
       end
@@ -16,6 +18,15 @@ module ActionCable
         connections.delete connection
       end
 
+      # Websocket connection implementations differ on when they'll mark a connection as stale. We basically never want a connection to go stale, as you
+      # then can't rely on being able to receive and send to it. So there's a 3 second heartbeat running on all connections. If the beat fails, we automatically
+      # disconnect.
+      def setup_heartbeat_timer
+        @heartbeat_timer ||= EventMachine.add_periodic_timer(BEAT_INTERVAL) do
+          EM.next_tick { connections.map &:beat }
+        end
+      end
+
       def open_connections_statistics
         connections.map(&:statistics)
       end