Revert "Merge pull request #22977 from rails/revert-22934-master"

This reverts commit d0393fccffc118a5de37654aa222774b66123393, reversing
changes made to 3b7ccadfc1c8dfec61af898167e1300b17f5cf25.

5 files changed, 44 insertions, 21 deletions

diff --git a/actioncable/lib/action_cable/channel/periodic_timers.rb b/actioncable/lib/action_cable/channel/periodic_timers.rb
index 25fe8e5e54..7f0fb37afc 100644
--- a/actioncable/lib/action_cable/channel/periodic_timers.rb
+++ b/actioncable/lib/action_cable/channel/periodic_timers.rb
@@ -28,7 +28,7 @@ module ActionCable
         def start_periodic_timers
           self.class.periodic_timers.each do |callback, options|
             active_periodic_timers << EventMachine::PeriodicTimer.new(options[:every]) do
-              connection.worker_pool.async.run_periodic_timer(self, callback)
+              connection.worker_pool.async_run_periodic_timer(self, callback)
             end
           end
         end
diff --git a/actioncable/lib/action_cable/connection/base.rb b/actioncable/lib/action_cable/connection/base.rb
index 977856d656..a8cfdf90f3 100644
--- a/actioncable/lib/action_cable/connection/base.rb
+++ b/actioncable/lib/action_cable/connection/base.rb
@@ -103,7 +103,7 @@ module ActionCable
 
       # Invoke a method on the connection asynchronously through the pool of thread workers.
       def send_async(method, *arguments)
-        worker_pool.async.invoke(self, method, *arguments)
+        worker_pool.async_invoke(self, method, *arguments)
       end
 
       # Return a basic hash of statistics for the connection keyed with `identifier`, `started_at`, and `subscriptions`.
diff --git a/actioncable/lib/action_cable/process/logging.rb b/actioncable/lib/action_cable/process/logging.rb
index 72b1a080d1..dce637b3ca 100644
--- a/actioncable/lib/action_cable/process/logging.rb
+++ b/actioncable/lib/action_cable/process/logging.rb
@@ -1,10 +1,7 @@
 require 'action_cable/server'
 require 'eventmachine'
-require 'celluloid'
 
 EM.error_handler do |e|
   puts "Error raised inside the event loop: #{e.message}"
   puts e.backtrace.join("\n")
 end
-
-Celluloid.logger = ActionCable.server.logger
diff --git a/actioncable/lib/action_cable/server/base.rb b/actioncable/lib/action_cable/server/base.rb
index 740e4b301e..cfd0a65f0f 100644
--- a/actioncable/lib/action_cable/server/base.rb
+++ b/actioncable/lib/action_cable/server/base.rb
@@ -1,6 +1,3 @@
-# FIXME: Cargo culted fix from https://github.com/celluloid/celluloid-pool/issues/10
-require 'celluloid/current'
-
 require 'em-hiredis'
 
 module ActionCable
diff --git a/actioncable/lib/action_cable/server/worker.rb b/actioncable/lib/action_cable/server/worker.rb
index e063b2a2e1..3b6c6d44a1 100644
--- a/actioncable/lib/action_cable/server/worker.rb
+++ b/actioncable/lib/action_cable/server/worker.rb
@@ -1,39 +1,68 @@
-require 'celluloid'
 require 'active_support/callbacks'
+require 'active_support/core_ext/module/attribute_accessors_per_thread'
+require 'concurrent'
 
 module ActionCable
   module Server
     # Worker used by Server.send_async to do connection work in threads. Only for internal use.
     class Worker
       include ActiveSupport::Callbacks
-      include Celluloid
 
-      attr_reader :connection
+      thread_mattr_accessor :connection
       define_callbacks :work
       include ActiveRecordConnectionManagement
 
+      def initialize(max_size: 5)
+        @pool = Concurrent::ThreadPoolExecutor.new(
+          min_threads: 1,
+          max_threads: max_size,
+          max_queue: 0,
+        )
+      end
+
+      def async_invoke(receiver, method, *args)
+        @pool.post do
+          invoke(receiver, method, *args)
+        end
+      end
+
       def invoke(receiver, method, *args)
-        @connection = receiver
+        begin
+          self.connection = receiver
 
-        run_callbacks :work do
-          receiver.send method, *args
+          run_callbacks :work do
+            receiver.send method, *args
+          end
+        rescue Exception => e
+          logger.error "There was an exception - #{e.class}(#{e.message})"
+          logger.error e.backtrace.join("\n")
+
+          receiver.handle_exception if receiver.respond_to?(:handle_exception)
+        ensure
+          self.connection = nil
         end
-      rescue Exception => e
-        logger.error "There was an exception - #{e.class}(#{e.message})"
-        logger.error e.backtrace.join("\n")
+      end
 
-        receiver.handle_exception if receiver.respond_to?(:handle_exception)
+      def async_run_periodic_timer(channel, callback)
+        @pool.post do
+          run_periodic_timer(channel, callback)
+        end
       end
 
       def run_periodic_timer(channel, callback)
-        @connection = channel.connection
+        begin
+          self.connection = channel.connection
 
-        run_callbacks :work do
-          callback.respond_to?(:call) ? channel.instance_exec(&callback) : channel.send(callback)
+          run_callbacks :work do
+            callback.respond_to?(:call) ? channel.instance_exec(&callback) : channel.send(callback)
+          end
+        ensure
+          self.connection = nil
         end
       end
 
       private
+
         def logger
           ActionCable.server.logger
         end