Re: LuaJIT and keeping objects alive

[Roberto Ierusalimschy <roberto@...>]

> The context it came up in was a module providing a try/finally
> mechanism. I was guided by earlier discussion on this list, and
> especially the techniques used in:
> 
>     <http://coxpcall.luaforge.net>
>     <http://lua-users.org/wiki/FinalizedExceptions>
>     <http://lua-users.org/lists/lua-l/2008-02/msg00243.html>
> 
> For the usual cases---that is, successful completion of the protected
> block, and ALSO errors raised during the execution of the protected
> block---then my wrapper functions will explicitly take care of
> running all the finalizers that have been registered.
> 
> But you made the point in an earlier thread that if protected blocks
> were allowed to yield, their thread might eventually end up being gc'd
> instead of resuming. So you said a fully general exception-handling
> mechanism had to make use of the __gc mechanism.

I think my suggestion (which was actually from someone else) was for
resource cleanup, which is not the same as exception handling. But
I may be wrong (now and/or earlier ;)

Anyway, currently I do not think it is wise to assume that an object
will not be finalized if it not going to be used.

-- Roberto