Function lua_sethook

extlibs/lua/src/ldebug.c:135–148

** This function can be called asynchronously (e.g. during a signal), ** under "reasonable" assumptions. ** Fields 'oldpc', 'basehookcount', and 'hookcount' (set by ** 'resethookcount') are for debug only, and it is no problem if they ** get arbitrary values (causes at most one wrong hook call). 'hookmask' ** is an atomic value. We assume that pointers are atomic too (e.g., gcc ** ensures that for

** always checked before being called (see 'luaD_hook').
*/
LUA_API void lua_sethook (lua_State *L, lua_Hook func, int mask, int count) {
  if (func == NULL || mask == 0) {  /* turn off hooks? */
    mask = 0;
    func = NULL;
  }
  if (isLua(L->ci))
    L->oldpc = L->ci->u.l.savedpc;
  L->hook = func;
  L->basehookcount = count;
  resethookcount(L);
  L->hookmask = cast_byte(mask);
  if (mask)
    settraps(L->ci);  /* to trace inside 'luaV_execute' */
}


LUA_API lua_Hook lua_gethook (lua_State *L) {