gc.lua

local ffi = require("ffi")
local C = ffi.C


ffi.cdef([[
unsigned int
sleep(unsigned int seconds); ]])


local function foo(no)
	print("FOO:", no)
	C.sleep(1)
	print("FOO:", no)
end


local R_mt = {}
R_mt.__index = R_mt


local function R(no)
	local self = setmetatable({}, R_mt)
	
	self.__gc = ffi.new("int[1]")
	ffi.gc(self.__gc, function() foo(no) end)
	
	self.no = no
	return self
end


local function main()
	local r = R(3)
end


main()