module Concurrent::Synchronization

def self.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

def self.full_memory_barrier
  JRubyAttrVolatile.full_memory_barrier
end

def self.full_memory_barrier
  TruffleRuby.full_memory_barrier
end

def self.full_memory_barrier
end