Safe configuration access

Author: pitr-ch

lib/concurrent/configuration.rb

@@ -1,6 +1,7 @@
 require 'thread'
 require 'concurrent/delay'
 require 'concurrent/errors'
+require 'concurrent/atomic/atomic'
 require 'concurrent/executor/thread_pool_executor'
 require 'concurrent/executor/timer_set'
 require 'concurrent/utility/processor_count'
@@ -111,8 +112,12 @@ def new_operation_pool
   end
 
   # create the default configuration on load
-  @configuration = Configuration.new
-  singleton_class.send :attr_reader, :configuration
+  @configuration = Atomic.new Configuration.new
+
+  # @return [Configuration]
+  def self.configuration
+    @configuration.value
+  end
 
   # Perform gem-level configuration.
   #

spec/support/example_group_extensions.rb

@@ -24,7 +24,7 @@ def rbx?
 
     def reset_gem_configuration
       return if @do_not_reset
-      Concurrent.instance_variable_set(:@configuration, Concurrent::Configuration.new)
+      Concurrent.instance_variable_get(:@configuration).value = Concurrent::Configuration.new
     end
 
     def kill_rogue_threads(warning = true)