require 'socket'

class SubKlass
	attr_reader :socket

	private

	def initialize(arrayparam = [], opts = {})
		socket, child = UNIXSocket.pair
		@pid = fork do
			STDIN.reopen(child)
			STDOUT.reopen(child)
			child.close
			socket.close
			arrayparam.unshift('/bin/cat')
			exec(*arrayparam, close_others: true)
		end

		child.close
		@socket = socket
	end
end

class Klass
	def method()
		# issues a write to @instance's socket
		@instance.socket.write('test')
		begin
			@instance.socket.read_nonblock(16)
		rescue
			retry
		end
	end

	def initialize(arrayparam: [])
		@instance = SubKlass.new(arrayparam, otherparam: :symbol)
	end
end

params = []
instance = Klass.new(arrayparam: params)
instance.method