Which Multithreading Solution?

[Drew Phil]

Hey there!

I'm trying to figure out which of D's many multithreading options 
to use for my application. I'm making a game that runs at 60 
frames per second that can also run user-made Lua scripts. I 
would like to have the Lua scripts run in a separate thread so 
they can't delay frames if there's a lot of work to do in a 
burst, but I also need it to be able to update and read from the 
thread where everything else is.

I don't think message passing is going to cut it because the Lua 
thread is going to need to be able to request to set a value in D 
on one line, and then request that value back on the next line, 
and that value needs to be updated at that point, not at the end. 
I've been marking things as __gshared to get them working, but I 
think that just makes a copy on all threads, which seems pretty 
excessive when mostly the Lua will just be reading values, and 
occasionally calling a function in D to change some values.

I think I should try to do some kind of lock thing, but I'm not 
really sure how that works. If someone could advise me on what 
tact I should take, that would be very helpful.

Thanks!