Re: Co routine local data / best practices

[Jim Pryor <lists+lua@...>]

On Wed, Dec 02, 2009 at 05:16:33PM -0800, Chris Gagnon wrote:
>    Your very close I'm just going to go ahead and explain it in code because
>    the problem really is an implementation one.
> 
>    LuaManager::StartCoroutine(char * func)
>    {
>            lua_getfield(MainState, LUA_GLOBALSINDEX, "ThreadTable");
>            lua_State *thread = lua_newthread(MainState);
>            int refID = luaL_ref(MainState, -2);
>          
>            // start func on the new thread some setup removed for brevity
>            int iRet = lua_resume(m_pLuaState, n);
>            if (iRet == 0)
>            {
>                // clean up i have refID in this case all is good
>            }       
>            else if (iRet == LUA_YIELD)
>            {
>                    -> i have a refID what do i do with it?
>                    ->   Attempting to avoid creating a map because I feel
>    like I should be able to pack it with thread.
>            }
>            else
>            {
>                // error
>            }
>    }
> 
>    int SleepSystem::call_c_sleep_function(lua_State * L)
>    {
>            // save off L and an associated time
>            return lua_yield(L);
>    }
> 
>    int SleepSystem::process(...)
>    {
>            // realizes that L should be resumes since it's sleep time is up
>            int iRet = lua_resume(L);
>            if (iRet == 0)
>            {
>                // clean up i have refID in this case all is good
>            }       
>            else if (iRet == LUA_YIELD)
>            {
>                    -> i cannot clean up because i don't have refID to do
>    luaL_unref(...)
>            }
>            else
>            {
>                // error
>            }
>    }

Sorry, none of this was obscure to me...it's what you're thinking will
go on in _between_ these functions that is obscure. Pretend that there
are calls lua_AssociateValue and lua_GetAssociatedValue that pack
whatever values you want together with the thread. Using them, can you fill in the
gaps some more so that I can see you start two threads (lets say simple
Lua functions), and have them each suspend by calling
SleepSystem::whatever, and then be resumed at the appropriate time, then
they stop. Maybe that will help me make a more useful suggestion about
how to implement lua_AssociateValue etc.

-- 
Jim Pryor
profjim@jimpryor.net