Convert weak -> locked reference

[Michael Cuddy <mcuddy@...>]

My framework creates userdata-objects and gives them to Lua.  To make sure
that I don't give the same object to Lua twice, I track them with weak
references (something that lua_pushuserdata() USED to do in 4.0 -- I'm not
arguing with the new behavior, but it is different ;-).  

Sometimes, I need to make sure that the object is not collected.
To do this, I need to convert the reference that I'm holding for the object
into a locked reference.  Currently, I'm doing something like this:

    // convert object->ref from a weak reference to a locked
    // reference.
    old_ref = object->ref;
    if (lua_getref(L,old_ref)) { // error: object was collected already }
    object->ref = lua_ref(L,1);
    lua_unref(L,old_ref);

When I need to convert the locked reference back into a weak reference ...

    old_ref = object->ref;
    lua_getref(L,old_ref);
    object->ref = lua_ref(L,0);
    lua_unref(L,old_ref);

Is there a better way to do this?  Is this legal? (is it moral?)

I've looked at the code for lua_getref() in lapi.c, is it legal/moral
to just twiddle the registry/weak registry "by hand" to accomplish what
I need done?

It would be really cool if Lua had a 'USERHANDLE' type -- works like userdata
(i.e.: can have tag methods) but is NOT GC'ed (and thus no need to mark/sweep
them) the lifetime of the objects would be entirely handled by the host
framework...

--
Mike Cuddy (mcuddy@FensEnde.com, MC312), Programmer, Daddy, Human.
Fen's Ende Software, Redwood City, CA, USA, Earth, Sol System, Milky Way.

       Now I lay me down to sleep / CVS, I pray, my code to keep.  
       If disks crash before I wake: / format, newfs, cvs up, make.

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