module Concurrent::Synchronization::MriAttrVolatile

def self.included(base)
  base.extend(ClassMethods)
end

def full_memory_barrier
  # relying on undocumented behavior of CRuby, GVL acquire has lock which ensures visibility of ivars
  # https://github.com/ruby/ruby/blob/ruby_2_2/thread_pthread.c#L204-L211
end