Re: Multithreaded Lua

[Nathaniel Lewis <linux.robotdude@...>]

So I understand (I'm fairly new to lua), when you yield a coroutine, it
will actually return from the lua_pcall inside C++?  Do I resume it from
C++ with lua_pcall again or is there a special resume command I missed
in the manual?
				Nathaniel

On Mon, 2010-07-19 at 17:21 -0400, Henk Boom wrote:
> On 19 July 2010 16:47, Nathaniel Lewis <linux.robotdude@gmail.com> wrote:
> >
> > I am currently writing a game engine for Linux that I intend to open
> > source.  I realize that I need some sort of script to go along with a map in
> > it to describe what will happen when.  I decided to turn to Lua as a script
> > because its syntax is simple and not too difficult to learn.  But I need the
> > interpreter to run as a separate thread than the main thread for reasons
> > like this:
> >
> > while encounter_Living("DemoEncounter") > 0 do
> >  -- Do something while the encounter is alive --
> > end
> > ui_Print("Encounter Killed");
> >
> > Currently all I have been able to do is have an update function called after
> > every frame is rendered but and waiting would cause the game to lock up.  Is
> > there any way to run the Lua interpreter as a separate thread from the main
> > thread for Windows and Unix?
> > Nathaniel Lewis
> 
> You probably want to wrap your update function in a coroutine.
> Something like this: (untested)
> 
> update = coroutine.wrap(function ()
>   while true do
>     while encounter_Living("DemoEncounter") > 0 do
>       -- Do something while the encounter is alive --
>       coroutine.yield() -- this temporarily returns from the function,
> resuming here when it's called again
>     end)
>     ui_Print("Encounter Killed");
>   end
> end)
> 
> Coroutines are a bit like threads, but instead of running in parallel
> to the rest of your program, they manually yield to it until they are
> resumed. For the details see
> 
> http://www.lua.org/manual/5.1/manual.html#2.11
> 
>     henk