Actual gc collection of nil?

["Research" <research@...>]

Hi,
I frequently see casual mention that the gc will collect something 
"eventually" or "sometime later". Does this hold true when calling 
lua_setgcthreshold(L, 0) in Lua 5.0 as well? Or does the fact the threshold 
is zero indicate that the nil keys and values will be collected when the gc 
runs?

I know the gc will _run_ when lua_setgcthreshold is called with a threshold 
of zero, I just want to know if _all_ nil keys/values will actually be 
collected then, or whether it takes some time or number of 
lua_setgcthreshold calls before it actually collects them. E.g. does calling 
lua_setgcthreshold multiple times in a row do anything after the initial 
call.

Thanks,
Brett