diff --git a/src/pre_generated-zmq.nobj.c b/src/pre_generated-zmq.nobj.c
index b78fc59..970605c 100644
--- a/src/pre_generated-zmq.nobj.c
+++ b/src/pre_generated-zmq.nobj.c
@@ -195,10 +195,10 @@ typedef struct obj_udata {
 } obj_udata;
 
 /* use static pointer as key to weak userdata table. */
-static char *obj_udata_weak_ref_key = "obj_udata_weak_ref_key";
+static char obj_udata_weak_ref_key[] = "obj_udata_weak_ref_key";
 
 /* use static pointer as key to module's private table. */
-static char *obj_udata_private_key = "obj_udata_private_key";
+static char obj_udata_private_key[] = "obj_udata_private_key";
 
 #if LUAJIT_FFI
 typedef struct ffi_export_symbol {
@@ -932,6 +932,7 @@ static const char zmq_ffi_lua_code[] = "local ffi=require\"ffi\"\n"
 "local tonumber = tonumber\n"
 "local tostring = tostring\n"
 "local rawset = rawset\n"
+"local setmetatable = setmetatable\n"
 "local p_config = package.config\n"
 "local p_cpath = package.cpath\n"
 "\n"
@@ -954,16 +955,7 @@ static const char zmq_ffi_lua_code[] = "local ffi=require\"ffi\"\n"
 "\n"
 "local _M, _priv, udata_new = ...\n"
 "\n"
-"local band = bit.band\n"
-"local d_getmetatable = debug.getmetatable\n"
-"local d_setmetatable = debug.setmetatable\n"
-"\n"
 "local OBJ_UDATA_FLAG_OWN		= 1\n"
-"local OBJ_UDATA_FLAG_LOOKUP	= 2\n"
-"local OBJ_UDATA_LAST_FLAG		= OBJ_UDATA_FLAG_LOOKUP\n"
-"\n"
-"local OBJ_TYPE_FLAG_WEAK_REF	= 1\n"
-"local OBJ_TYPE_SIMPLE					= 2\n"
 "\n"
 "local function ffi_safe_cdef(block_name, cdefs)\n"
 "	local fake_type = \"struct sentinel_\" .. block_name .. \"_ty\"\n"
@@ -1005,154 +997,6 @@ static const char zmq_ffi_lua_code[] = "local ffi=require\"ffi\"\n"
 "\n"
 "]])\n"
 "\n"
-"-- cache mapping of cdata to userdata\n"
-"local weak_objects = setmetatable({}, { __mode = \"v\" })\n"
-"\n"
-"local function obj_udata_luacheck_internal(obj, type_mt, not_delete)\n"
-"	local obj_mt = d_getmetatable(obj)\n"
-"	if obj_mt == type_mt then\n"
-"		-- convert userdata to cdata.\n"
-"		return ffi.cast(\"obj_udata *\", obj)\n"
-"	end\n"
-"	if not_delete then\n"
-"		error(\"(expected `\" .. type_mt['.name'] .. \"`, got \" .. type(obj) .. \")\", 3)\n"
-"	end\n"
-"end\n"
-"\n"
-"local function obj_udata_luacheck(obj, type_mt)\n"
-"	local ud = obj_udata_luacheck_internal(obj, type_mt, true)\n"
-"	return ud.obj\n"
-"end\n"
-"\n"
-"local function obj_udata_to_cdata(objects, ud_obj, c_type, ud_mt)\n"
-"	-- convert userdata to cdata.\n"
-"	local c_obj = ffi.cast(c_type, obj_udata_luacheck(ud_obj, ud_mt))\n"
-"	-- cache converted cdata\n"
-"	rawset(objects, ud_obj, c_obj)\n"
-"	return c_obj\n"
-"end\n"
-"\n"
-"local function obj_udata_luadelete(ud_obj, type_mt)\n"
-"	local ud = obj_udata_luacheck_internal(ud_obj, type_mt, false)\n"
-"	if not ud then return nil, 0 end\n"
-"	local obj, flags = ud.obj, ud.flags\n"
-"	-- null userdata.\n"
-"	ud.obj = nil\n"
-"	ud.flags = 0\n"
-"	-- invalid userdata, by setting the metatable to nil.\n"
-"	d_setmetatable(ud_obj, nil)\n"
-"	return obj, flags\n"
-"end\n"
-"\n"
-"local function obj_udata_luapush(obj, type_mt, obj_type, flags)\n"
-"	if obj == nil then return end\n"
-"\n"
-"	-- apply type's dynamic caster.\n"
-"	if obj_type.dcaster ~= nil then\n"
-"		local obj_ptr = ffi.new(\"void *[1]\", obj)\n"
-"		local type_ptr = ffi.new(\"obj_type *[1]\", obj_type)\n"
-"		obj_type.dcaster(obj_ptr, type_ptr)\n"
-"		obj = obj_ptr[1]\n"
-"		type = type_ptr[1]\n"
-"	end\n"
-"\n"
-"	-- create new userdata\n"
-"	local ud_obj = udata_new(ffi.sizeof\"obj_udata\", type_mt)\n"
-"	local ud = ffi.cast(\"obj_udata *\", ud_obj)\n"
-"	-- init. object\n"
-"	ud.obj = obj\n"
-"	ud.flags = flags\n"
-"\n"
-"	return ud_obj\n"
-"end\n"
-"\n"
-"local function obj_udata_luadelete_weak(ud_obj, type_mt)\n"
-"	local ud = obj_udata_luacheck_internal(ud_obj, type_mt, false)\n"
-"	if not ud then return nil, 0 end\n"
-"	local obj, flags = ud.obj, ud.flags\n"
-"	-- null userdata.\n"
-"	ud.obj = nil\n"
-"	ud.flags = 0\n"
-"	-- invalid userdata, by setting the metatable to nil.\n"
-"	d_setmetatable(ud_obj, nil)\n"
-"	-- remove object from weak ref. table.\n"
-"	local obj_key = tonumber(ffi.cast('uintptr_t', obj))\n"
-"	weak_objects[obj_key] = nil\n"
-"	return obj, flags\n"
-"end\n"
-"\n"
-"local function obj_udata_luapush_weak(obj, type_mt, obj_type, flags)\n"
-"	if obj == nil then return end\n"
-"\n"
-"	-- apply type's dynamic caster.\n"
-"	if obj_type.dcaster ~= nil then\n"
-"		local obj_ptr = ffi.new(\"void *[1]\", obj)\n"
-"		local type_ptr = ffi.new(\"obj_type *[1]\", obj_type)\n"
-"		obj_type.dcaster(obj_ptr, type_ptr)\n"
-"		obj = obj_ptr[1]\n"
-"		type = type_ptr[1]\n"
-"	end\n"
-"\n"
-"	-- lookup object in weak ref. table.\n"
-"	local obj_key = tonumber(ffi.cast('uintptr_t', obj))\n"
-"	local ud_obj = weak_objects[obj_key]\n"
-"	if ud_obj ~= nil then return ud_obj end\n"
-"\n"
-"	-- create new userdata\n"
-"	ud_obj = udata_new(ffi.sizeof\"obj_udata\", type_mt)\n"
-"	local ud = ffi.cast(\"obj_udata *\", ud_obj)\n"
-"	-- init. object\n"
-"	ud.obj = obj\n"
-"	ud.flags = flags\n"
-"\n"
-"	-- cache weak reference to object.\n"
-"	weak_objects[obj_key] = ud_obj\n"
-"\n"
-"	return ud_obj\n"
-"end\n"
-"\n"
-"local function obj_simple_udata_luacheck(ud_obj, type_mt)\n"
-"	local obj_mt = d_getmetatable(ud_obj)\n"
-"	if obj_mt == type_mt then\n"
-"		-- convert userdata to cdata.\n"
-"		return ffi.cast(\"void *\", ud_obj)\n"
-"	end\n"
-"	error(\"(expected `\" .. type_mt['.name'] .. \"`, got \" .. type(ud_obj) .. \")\", 3)\n"
-"end\n"
-"\n"
-"local function obj_simple_udata_to_cdata(objects, ud_obj, c_type, ud_mt)\n"
-"	-- convert userdata to cdata.\n"
-"	local c_obj = ffi.cast(c_type, obj_simple_udata_luacheck(ud_obj, ud_mt))[0]\n"
-"	-- cache converted cdata\n"
-"	rawset(objects, ud_obj, c_obj)\n"
-"	return c_obj\n"
-"end\n"
-"\n"
-"local function obj_embed_udata_to_cdata(objects, ud_obj, c_type, ud_mt)\n"
-"	-- convert userdata to cdata.\n"
-"	local c_obj = ffi.cast(c_type, obj_simple_udata_luacheck(ud_obj, ud_mt))\n"
-"	-- cache converted cdata\n"
-"	rawset(objects, ud_obj, c_obj)\n"
-"	return c_obj\n"
-"end\n"
-"\n"
-"local function obj_simple_udata_luadelete(ud_obj, type_mt)\n"
-"	-- invalid userdata, by setting the metatable to nil.\n"
-"	d_setmetatable(ud_obj, nil)\n"
-"end\n"
-"\n"
-"local function obj_simple_udata_luapush(c_obj, size, type_mt)\n"
-"	if c_obj == nil then return end\n"
-"\n"
-"	-- create new userdata\n"
-"	local ud_obj = udata_new(size, type_mt)\n"
-"	local cdata = ffi.cast(\"void *\", ud_obj)\n"
-"	-- init. object\n"
-"	ffi.copy(cdata, c_obj, size)\n"
-"\n"
-"	return ud_obj, cdata\n"
-"end\n"
-"\n"
 "local function obj_ptr_to_id(ptr)\n"
 "	return tonumber(ffi.cast('uintptr_t', ptr))\n"
 "end\n"
@@ -1164,7 +1008,7 @@ static const char zmq_ffi_lua_code[] = "local ffi=require\"ffi\"\n"
 "local function register_default_constructor(_pub, obj_name, constructor)\n"
 "	local pub_constructor = _pub[obj_name]\n"
 "	if type(pub_constructor) == 'table' then\n"
-"		d_setmetatable(pub_constructor, { __call = function(t,...)\n"
+"		setmetatable(pub_constructor, { __call = function(t,...)\n"
 "			return constructor(...)\n"
 "		end,\n"
 "		__metatable = false,\n"
@@ -1282,6 +1126,13 @@ static const char zmq_ffi_lua_code[] = "local ffi=require\"ffi\"\n"
 "end\n"
 "_pub.zmq = _M\n"
 "for obj_name,pub in pairs(_M) do\n"
+"	if type(pub) == 'table' then\n"
+"		local new_pub = {}\n"
+"		for k,v in pairs(pub) do\n"
+"			new_pub[k] = v\n"
+"		end\n"
+"		pub = new_pub\n"
+"	end\n"
 "	_pub[obj_name] = pub\n"
 "end\n"
 "\n"
@@ -1346,7 +1197,7 @@ static const char zmq_ffi_lua_code[] = "local ffi=require\"ffi\"\n"
 "	function obj_type_ZMQ_Socket_delete(ptr)\n"
 "		local id = obj_ptr_to_id(ptr)\n"
 "		local flags = obj_flags[id]\n"
-"		if not flags then return ptr, 0 end\n"
+"		if not flags then return nil, 0 end\n"
 "		ffi.gc(ptr, nil)\n"
 "		obj_flags[id] = nil\n"
 "		return ptr, flags\n"
@@ -1433,7 +1284,7 @@ static const char zmq_ffi_lua_code[] = "local ffi=require\"ffi\"\n"
 "	function obj_type_ZMQ_Ctx_delete(ptr)\n"
 "		local id = obj_ptr_to_id(ptr)\n"
 "		local flags = obj_flags[id]\n"
-"		if not flags then return ptr, 0 end\n"
+"		if not flags then return nil, 0 end\n"
 "		ffi.gc(ptr, nil)\n"
 "		obj_flags[id] = nil\n"
 "		return ptr, flags\n"
@@ -1482,7 +1333,7 @@ static const char zmq_ffi_lua_code[] = "local ffi=require\"ffi\"\n"
 "	function obj_type_ZMQ_StopWatch_delete(ptr)\n"
 "		local id = obj_ptr_to_id(ptr)\n"
 "		local flags = obj_flags[id]\n"
-"		if not flags then return ptr, 0 end\n"
+"		if not flags then return nil, 0 end\n"
 "		ffi.gc(ptr, nil)\n"
 "		obj_flags[id] = nil\n"
 "		return ptr, flags\n"
@@ -1694,8 +1545,8 @@ static const char zmq_ffi_lua_code[] = "local ffi=require\"ffi\"\n"
 "-- Start \"ZMQ_Socket\" FFI interface\n"
 "-- method: close\n"
 "function _meth.ZMQ_Socket.close(self)\n"
-"  local self,this_flags1 = obj_type_ZMQ_Socket_delete(self)\n"
-"  if(band(this_flags1,OBJ_UDATA_FLAG_OWN) == 0) then return end\n"
+"  local self, free,this_flags1=obj_type_ZMQ_Socket_delete(self)\n"
+"  if not self then return end\n"
 "  local rc_zmq_close1\n"
 "  rc_zmq_close1 = C.zmq_close(self)\n"
 "  -- check for error.\n"
@@ -2111,8 +1962,8 @@ static const char zmq_ffi_lua_code[] = "local ffi=require\"ffi\"\n"
 "-- Start \"ZMQ_Ctx\" FFI interface\n"
 "-- method: term\n"
 "function _meth.ZMQ_Ctx.term(self)\n"
-"  local self,this_flags1 = obj_type_ZMQ_Ctx_delete(self)\n"
-"  if(band(this_flags1,OBJ_UDATA_FLAG_OWN) == 0) then return end\n"
+"  local self, free,this_flags1=obj_type_ZMQ_Ctx_delete(self)\n"
+"  if not self then return end\n"
 "  local rc_zmq_term1\n"
 "  rc_zmq_term1 = C.zmq_term(self)\n"
 "  -- check for error.\n"
@@ -2160,8 +2011,8 @@ static const char zmq_ffi_lua_code[] = "local ffi=require\"ffi\"\n"
 "register_default_constructor(_pub,\"ZMQ_StopWatch\",_pub.ZMQ_StopWatch.start)\n"
 "-- method: stop\n"
 "function _meth.ZMQ_StopWatch.stop(self)\n"
-"  local self,this_flags1 = obj_type_ZMQ_StopWatch_delete(self)\n"
-"  if(band(this_flags1,OBJ_UDATA_FLAG_OWN) == 0) then return end\n"
+"  local self, free,this_flags1=obj_type_ZMQ_StopWatch_delete(self)\n"
+"  if not self then return end\n"
 "  local usecs1\n"
 "  usecs1 = C.zmq_stopwatch_stop(self)\n"
 "  usecs1 = tonumber(usecs1)\n"