JezK
Edit File: volatile.rb
module ThreadSafe module Util module Volatile # Provides +volatile+ (in the JVM's sense) attribute accessors implemented # atop of the +AtomicReference+s. # # Usage: # class Foo # extend ThreadSafe::Util::Volatile # attr_volatile :foo, :bar # # def initialize(bar) # super() # must super() into parent initializers before using the volatile attribute accessors # self.bar = bar # end # # def hello # my_foo = foo # volatile read # self.foo = 1 # volatile write # cas_foo(1, 2) # => true | a strong CAS # end # end def attr_volatile(*attr_names) return if attr_names.empty? include(Module.new do atomic_ref_setup = attr_names.map {|attr_name| "@__#{attr_name} = ThreadSafe::Util::AtomicReference.new"} initialize_copy_setup = attr_names.zip(atomic_ref_setup).map do |attr_name, ref_setup| "#{ref_setup}(other.instance_variable_get(:@__#{attr_name}).get)" end class_eval <<-RUBY_EVAL, __FILE__, __LINE__ + 1 def initialize(*) super #{atomic_ref_setup.join('; ')} end def initialize_copy(other) super #{initialize_copy_setup.join('; ')} end RUBY_EVAL attr_names.each do |attr_name| class_eval <<-RUBY_EVAL, __FILE__, __LINE__ + 1 def #{attr_name} @__#{attr_name}.get end def #{attr_name}=(value) @__#{attr_name}.set(value) end def compare_and_set_#{attr_name}(old_value, new_value) @__#{attr_name}.compare_and_set(old_value, new_value) end RUBY_EVAL alias_method :"cas_#{attr_name}", :"compare_and_set_#{attr_name}" alias_method :"lazy_set_#{attr_name}", :"#{attr_name}=" end end) end end end end