Tolua memory leak?

[awheeler@...]

Hey folks,

I'm using the tolua alpha (?) with lua v4.x and seem to be running 
into a memory leak.  I've built a package for class Foo: a simple 
class that has two member-functions as well as a simple constructor 
and destructor.  I built a binary file that executes the following 
script:

oFoo = Foo:new()
oFoo:delete()

When the script finishes, the program exits - and the debugger 
reports a memory leak.

I've tracked the memory-leak down to a synchro issue with lua_close() 
and tolua's userdata garbage-collection tag-method.  Here is what 
seems to be going on:

1. lua_close() calls collect_userdata().  This function strips 
the "udt" list/table of all its userdata objects, and moves them to 
a "collected" hash-table.  The function then returns.

2. lua_close() then calls something like collectgcTM(), which 
iterates through the list of collected userdata objects and executes 
any gc tag-method for any object that has a gc tag-method.

3. an object pointing to the address of my now-deleted oFoo object 
has a gc tag-method, so its tag-method is executed.  Tolua has set 
the tag-method to something like instance_gc().

4. instance_gc() calls toluaI_undo_clone().  

5. toluaI_undo_clone() calls push_userdata() to push a pointer to the 
clone onto the Lua stack.  push_userdata() ultimately instantiates a 
new userdata object entry - and puts it on the udt list (!).

6. toluaI_undo_clone() ultimately returns, and collectgcTM() 
ultimately returns, too, while the userdata object remains on the udt 
list...

7. tolua_close() finally returns: but it never goes back and re-
cleans up the udt list.  Hence the userdata object created during the 
gc tag-method's call to push_userdata() never gets cleaned up.  

Is this a known problem?  Can anyone else verify the above sequence 
of events?  It seems that I could just call collect_userdata() right 
after collect_gcTM() and this would solve the problem: but it's, of 
course, a fairly nasty hack.  Otherwise I don't yet see a nice way to 
solve this problem.

Any thoughts?

Thanks for any help,

-andrew