Require only necessary concurrent-ruby classes.

Gemfile.lock

@@ -137,7 +137,7 @@ PATH
       activesupport (= 5.0.0.alpha)
       arel (= 7.0.0.alpha)
     activesupport (5.0.0.alpha)
-      concurrent-ruby (~> 1.0.0.pre3, < 2.0.0)
+      concurrent-ruby (~> 1.0.0.pre5, < 2.0.0)
       i18n (~> 0.7)
       json (~> 1.7, >= 1.7.7)
       method_source
@@ -201,7 +201,7 @@ GEM
       coffee-script-source
       execjs
     coffee-script-source (1.9.1.1)
-    concurrent-ruby (1.0.0.pre4)
+    concurrent-ruby (1.0.0.pre5)
     connection_pool (2.2.0)
     dalli (2.7.4)
     dante (0.2.0)

actionpack/test/controller/live_stream_test.rb

 require 'abstract_unit'
-require 'concurrent/atomics'
+require 'concurrent/atomic/count_down_latch'
 Thread.abort_on_exception = true
 
 module ActionController

actionpack/test/dispatch/live_response_test.rb

 require 'abstract_unit'
-require 'concurrent/atomics'
+require 'concurrent/atomic/count_down_latch'
 
 module ActionController
   module Live

actionview/lib/action_view/dependency_tracker.rb

-require 'concurrent'
+require 'concurrent/map'
 require 'action_view/path_set'
 
 module ActionView

actionview/lib/action_view/digestor.rb

-require 'concurrent'
+require 'concurrent/map'
 require 'action_view/dependency_tracker'
 require 'monitor'
 

actionview/lib/action_view/lookup_context.rb

-require 'concurrent'
+require 'concurrent/map'
 require 'active_support/core_ext/module/remove_method'
 require 'active_support/core_ext/module/attribute_accessors'
 require 'action_view/template/resolver'

actionview/lib/action_view/renderer/partial_renderer.rb

 require 'action_view/renderer/partial_renderer/collection_caching'
-require 'concurrent'
+require 'concurrent/map'
 
 module ActionView
   class PartialIteration

activejob/lib/active_job/async_job.rb

-require 'concurrent'
+require 'concurrent/map'
+require 'concurrent/scheduled_task'
+require 'concurrent/executor/thread_pool_executor'
+require 'concurrent/utility/processor_counter'
 
 module ActiveJob
   # == Active Job Async Job

activejob/test/adapters/async.rb

-require 'concurrent'
 require 'active_job/async_job'
 
 ActiveJob::Base.queue_adapter = :async

activemodel/lib/active_model/attribute_methods.rb

-require 'concurrent'
+require 'concurrent/map'
 require 'mutex_m'
 
 module ActiveModel

activerecord/lib/active_record/attribute_methods.rb

 require 'active_support/core_ext/enumerable'
 require 'active_support/core_ext/string/filters'
 require 'mutex_m'
-require 'concurrent'
+require 'concurrent/map'
 
 module ActiveRecord
   # = Active Record Attribute Methods

activerecord/lib/active_record/connection_adapters/abstract/connection_pool.rb

 require 'thread'
-require 'concurrent'
+require 'concurrent/map'
 require 'monitor'
 
 module ActiveRecord

activerecord/lib/active_record/type/type_map.rb

-require 'concurrent'
+require 'concurrent/map'
 
 module ActiveRecord
   module Type

activerecord/test/cases/base_test.rb

@@ -26,7 +26,7 @@
 require 'models/car'
 require 'models/bulb'
 require 'rexml/document'
-require 'concurrent/atomics'
+require 'concurrent/atomic/count_down_latch'
 
 class FirstAbstractClass < ActiveRecord::Base
   self.abstract_class = true

activerecord/test/cases/connection_pool_test.rb

 require "cases/helper"
-require 'concurrent/atomics'
+require 'concurrent/atomic/count_down_latch'
 
 module ActiveRecord
   module ConnectionAdapters

activesupport/activesupport.gemspec

@@ -24,6 +24,6 @@
   s.add_dependency 'json',       '~> 1.7', '>= 1.7.7'
   s.add_dependency 'tzinfo',     '~> 1.1'
   s.add_dependency 'minitest',   '~> 5.1'
-  s.add_dependency 'concurrent-ruby', '~> 1.0.0.pre3', '< 2.0.0'
+  s.add_dependency 'concurrent-ruby', '~> 1.0.0.pre5', '< 2.0.0'
   s.add_dependency 'method_source'
 end

activesupport/lib/active_support/concurrency/latch.rb

-require 'concurrent/atomics'
+require 'concurrent/atomic/count_down_latch'
 
 module ActiveSupport
   module Concurrency
@@ -8,7 +8,7 @@ def initialize(count = 1)
         ActiveSupport::Deprecation.warn("ActiveSupport::Concurrency::Latch is deprecated. Please use Concurrent::CountDownLatch instead.")
         super(count)
       end
-      
+
       alias_method :release, :count_down
 
       def await

activesupport/lib/active_support/dependencies.rb

 require 'set'
 require 'thread'
-require 'concurrent'
+require 'concurrent/map'
 require 'pathname'
 require 'active_support/core_ext/module/aliasing'
 require 'active_support/core_ext/module/attribute_accessors'

activesupport/lib/active_support/inflector/inflections.rb

-require 'concurrent'
+require 'concurrent/map'
 require 'active_support/core_ext/array/prepend_and_append'
 require 'active_support/i18n'
 

activesupport/lib/active_support/key_generator.rb

-require 'concurrent'
+require 'concurrent/map'
 require 'openssl'
 
 module ActiveSupport

activesupport/lib/active_support/notifications/fanout.rb

 require 'mutex_m'
-require 'concurrent'
+require 'concurrent/map'
 
 module ActiveSupport
   module Notifications

activesupport/lib/active_support/values/time_zone.rb

 require 'tzinfo'
-require 'concurrent'
+require 'concurrent/map'
 require 'active_support/core_ext/object/blank'
 require 'active_support/core_ext/object/try'
 

activesupport/test/share_lock_test.rb

 require 'abstract_unit'
-require 'concurrent/atomics'
+require 'concurrent/atomic/count_down_latch'
 require 'active_support/concurrency/share_lock'
 
 class ShareLockTest < ActiveSupport::TestCase