Remove autoload usages

Author: pitr-ch

lib/concurrent/map.rb

@@ -1,23 +1,23 @@
 require 'thread'
 
 module Concurrent
-  autoload :JRubyMapBackend,           'concurrent/thread_safe/jruby_map_backend'
-  autoload :MriMapBackend,             'concurrent/thread_safe/mri_map_backend'
-  autoload :NonConcurrentMapBackend,   'concurrent/thread_safe/non_concurrent_map_backend'
-  autoload :AtomicReferenceMapBackend, 'concurrent/thread_safe/atomic_reference_map_backend'
-  autoload :SynchronizedMapBackend,    'concurrent/thread_safe/synchronized_map_backend'
-
   # @!visibility private
   module ThreadSafe
 
     # @!visibility private
     MapBackend = if defined?(RUBY_ENGINE)
                    case RUBY_ENGINE
-                   when 'jruby'; JRubyMapBackend
-                   when 'ruby';  MriMapBackend
-                   when 'rbx';   AtomicReferenceMapBackend
+                   when 'jruby'
+                     JRubyMapBackend
+                   when 'ruby'
+                     require 'concurrent/thread_safe/mri_map_backend'
+                     MriMapBackend
+                   when 'rbx'
+                     require 'concurrent/thread_safe/atomic_reference_map_backend'
+                     AtomicReferenceMapBackend
                    else
                      warn 'Concurrent::Map: unsupported Ruby engine, using a fully synchronized Concurrent::Map implementation' if $VERBOSE
+                     require 'concurrent/thread_safe/synchronized_map_backend'
                      SynchronizedMapBackend
                    end
                  else
@@ -31,7 +31,7 @@ module ThreadSafe
   # -- for instance, it does not necessarily retain ordering by insertion time as `Hash`
   # does. For most uses it should do fine though, and we recommend you consider
   # `Concurrent::Map` instead of `Concurrent::Hash` for your concurrency-safe hash needs.
-  # 
+  #
   # > require 'concurrent'
   # >
   # > map = Concurrent::Map.new

lib/concurrent/thread_safe.rb

@@ -1,9 +1,9 @@
 require 'concurrent/utility/engine'
 require 'concurrent/thread_safe/synchronized_delegator'
+require 'concurrent/map'
+require 'concurrent/thread_safe/util'
 
 module Concurrent
-  autoload :Map,  'concurrent/map'
-  autoload :Util, 'concurrent/thread_safe/util'
 
   # Various classes within allows for +nil+ values to be stored,
   # so a special +NULL+ token is required to indicate the "nil-ness".

lib/concurrent/thread_safe/mri_map_backend.rb

@@ -1,8 +1,10 @@
+require 'concurrent/thread_safe/non_concurrent_map_backend'
+
 module Concurrent
 
   # @!visibility private
   module ThreadSafe
-        
+
     # @!visibility private
     class MriMapBackend < NonConcurrentMapBackend
 

lib/concurrent/thread_safe/synchronized_map_backend.rb

@@ -1,3 +1,5 @@
+require 'concurrent/thread_safe/non_concurrent_map_backend'
+
 module Concurrent
 
   # @!visibility private

lib/concurrent/thread_safe/util.rb

@@ -9,14 +9,14 @@ module Util
       FIXNUM_BIT_SIZE = (0.size * 8) - 2
       MAX_INT         = (2 ** FIXNUM_BIT_SIZE) - 1
       CPU_COUNT       = 16 # is there a way to determine this?
-
-      autoload :Tuple,           'concurrent/tuple'
-      autoload :Adder,           'concurrent/thread_safe/util/adder'
-      autoload :CheapLockable,   'concurrent/thread_safe/util/cheap_lockable'
-      autoload :PowerOfTwoTuple, 'concurrent/thread_safe/util/power_of_two_tuple'
-      autoload :Volatile,        'concurrent/thread_safe/util/volatile'
-      autoload :Striped64,       'concurrent/thread_safe/util/striped64'
-      autoload :XorShiftRandom,  'concurrent/thread_safe/util/xor_shift_random'
     end
   end
 end
+
+require 'concurrent/tuple'
+require 'concurrent/thread_safe/util/volatile'
+require 'concurrent/thread_safe/util/striped64'
+require 'concurrent/thread_safe/util/adder'
+require 'concurrent/thread_safe/util/cheap_lockable'
+require 'concurrent/thread_safe/util/power_of_two_tuple'
+