Re: rapid lifetime based collection of transient user data objects?

[Ross Bencina <rossb-lists@...>]

On 29/10/2011 6:03 PM, Joshua Jensen wrote:
> I can't recall if I ever did a standalone LuaRC 5.1, but the reference
> counting is definitely in the LuaPlus [1] source code. Look for
> LUA_REFCOUNT and copy the changes into your copy of Lua. It works in
> almost all instances, and it is very effective at keeping memory under
> control. I also like that it adds deterministic finalization to Lua.

Thanks for your fast reply Josh,

Is there a write-up somewhere of how the LuaPlus reference counting 
works? I'm wondering about things like: Does it replace the current Lua 
GC with reference counting for all objects? or can it be applied 
selectively to certain types? Does it perform cycle detection? How does 
it performe compared to the standard Lua GC?

One thing that would concern me about using eager reference counting for 
absolutely everything is that it could cause spikes in CPU usage when a 
large tree of objects becomes unreachable -- whereas with incremental GC 
the time taken by a GC cycle can be bounded. Perhaps there is a way of 
having incremental/bounded time resource deallocation with reference 
counting too.

Thanks

Ross.