Re: Hooking into garbage collection

[Philipp Janda <siffiejoe@...>]

Am 28.12.2013 03:41 schröbte Sean Conner:
> 	local mt =
> 	{
> 	  __gc = function(u)
> 	    call_magic_cleanup_stuff()
> 	    setmetatable({},getmetatable(u))
> 	  end
> 	}
>
> 	setmetatable({},mt)
>
> Doing this for Lua 5.1 is not quite as easy, as you need to use a userdata
> object (say, a pointer to int) instead of a Lua table, but the concept is
> the same.

Lua 5.1 had `newproxy` for that. E.g.:

    local sentinel = newproxy and newproxy( true )
                              or setmetatable( {}, { __gc = true } )
    getmetatable( sentinel ).__gc = function() writecache( c ) end

>    -spc

Philipp