expose Concurrent::Synchronization::Volatile module

Author: colinsurprenant

lib/concurrent/synchronization.rb

@@ -5,6 +5,7 @@
 require 'concurrent/synchronization/jruby_object'
 require 'concurrent/synchronization/rbx_object'
 require 'concurrent/synchronization/object'
+require 'concurrent/synchronization/volatile'
 
 require 'concurrent/synchronization/abstract_lockable_object'
 require 'concurrent/synchronization/mri_lockable_object'

lib/concurrent/synchronization/volatile.rb

@@ -0,0 +1,35 @@
+module Concurrent
+  module Synchronization
+
+    # Volatile adds the attr_volatile class method when included.
+    #
+    # @example
+    #   class Foo
+    #     include Concurrent::Synchronization::Volatile
+    #
+    #     attr_volatile :bar
+    #
+    #     def initialize
+    #       @volatile_bar = 1
+    #     end
+    #   end
+    #
+    #  foo = Foo.new
+    #  foo.bar
+    #  => 1
+    #  foo.bar = 2
+    #  => 2
+
+    Volatile = case
+    when Concurrent.on_cruby?
+      MriAttrVolatile
+    when Concurrent.on_jruby?
+      JRubyAttrVolatile
+    when Concurrent.on_rbx?
+      RbxAttrVolatile
+    else
+      warn 'Possibly unsupported Ruby implementation'
+      MriAttrVolatile
+    end
+  end
+end