Re: Lua 4.1 Alpha and Win32 Multithreading

[Roberto Ierusalimschy <roberto@...>]

> First, the Lua 4.1 LUA_USERSTATE #define to allow inclusion of state
> code into the lua_State structure in lstate.h was not sufficient to
> bring this online.  No code needs to be added to the lua_State.  The
> code to support "proper" multithreading (through this technique anyway)
> has to be in global_State.

I have implemented something along your suggestions using the current
macros. Instead of putting the "lock" stuff in global_State, I created
a new structure for them, and set LUA_USERSTATE to be a pointer to this
structure. When I create the state (with lua_open), I allocate this
structure:

  *(mystruct **)L = malloc(sizeof(mystruct));
  /* initialize mystruct ... */

When I create new stacks, I copy the pointer from the old
thread to the new one:

  NL = lua_newthread(L, 0);
  *(mystruct **)NL = *(mystruct **)L;

That way, all threads share the same structure (and we need no extra support
from Lua).

-- Roberto