Re: how to implement cleaning function ( atexit() like )

[Graham Wakefield <wakefield@...>]

Note that this doesn't work for Lua 5.1, because tables do not invoke __gc metamethods.

For Lua 5.1 a workaround is to use newproxy():
http://lua-users.org/wiki/HiddenFeatures

E.g.:

t = newproxy(true)
getmetatable(t).__gc = function() print("bye bye t") end
-- later:
t = nil
collectgarbage()
collectgarbage()

The same newproxy() method is available in LuaJIT, or you could use an ffi metatype instead.

On Apr 4, 2013, at 8:38 PM, Luiz Henrique de Figueiredo wrote:

>> 2/ how can I implement atexit like stuff in Lua ?
> 
> Set a gc metamethod for a table that is keep safely in a global variable.
> 
>> 3/ is this function called even when the daemon will receive a SIGQUIT
>> signal ?
> 
> The standard Lua interpreter does not handle SIGQUIT. You can either
> change it or use your own Lua host. You can also try to do signal
> handling using luaposix.
>