Como "pausar/suspender" execução código C com corotina Lua

coroutine_lua.c

#include <stdio.h>
#include <string.h>
#include <lua.h>
#include <lauxlib.h>
#include <lualib.h>


double arg;

static int l_csleep_cont (lua_State *L) {
  printf("continuando!\n");
  lua_pushnumber(L, arg);
  return 1;
}

static int l_csleep (lua_State *L) {
  arg = luaL_checknumber(L, 1);
  return lua_yieldk(L, 0, 0, l_csleep_cont);
}

int main (void) {
  char *buff = "return csleep(10)";
  int status;
  lua_State *L = luaL_newstate();
  lua_State *thread;  
  luaL_openlibs(L);

  lua_pushcfunction(L, l_csleep);
  lua_setglobal(L, "csleep");

  thread = lua_newthread(L);
  status = luaL_loadbuffer(thread, buff, strlen(buff), "line") ||
           lua_resume(thread, NULL, 0);
  while (status == LUA_YIELD) {
      printf("cedeu a vez: ");
      printf("%s\n", lua_tostring(thread, -1));
      status = lua_resume(thread, thread, 0);
  }
  if (status == LUA_ERRRUN) {
    fprintf(stderr, "ERRO: %s\n", lua_tostring(thread, -1));
    lua_pop(L, 1);  /* pop error message from the stack */
    return 1;
  } else {
    const char *retval = lua_tostring(thread, -1);
    printf("Retorno: %s\n", retval);
  }
  lua_close(L);
  return 0;
}