static int
lread(lua_State *L) {
struct boxreader * box = lua_touserdata(L, 1);
luaL_checktype(L, 2, LUA_TFUNCTION);
struct stm_copy * copy = stm_copy(box->obj);
if (copy == box->lastcopy) {
// not update
stm_releasecopy(copy);
lua_pushboolean(L, 0);
return 1;
}
stm_releasecopy(box->lastcopy);
box->lastcopy = copy;
if (copy) {
lua_settop(L, 3);
lua_replace(L, 1);
lua_settop(L, 2);
lua_pushlightuserdata(L, copy->msg);
lua_pushinteger(L, copy->sz);
lua_pushvalue(L, 1);
lua_call(L, 3, LUA_MULTRET);
lua_pushboolean(L, 1);
lua_replace(L, 1);
return lua_gettop(L);
} else {
lua_pushboolean(L, 0);
return 1;
}
}
static void
stm_update(struct stm_object *obj, void *msg, int32_t sz) {
struct stm_copy *copy = stm_newcopy(msg, sz);
WLock l(obj->lock);
struct stm_copy *oldcopy = obj->copy;
obj->copy = copy;
stm_releasecopy(oldcopy);
}
static int
ldeletereader(lua_State *L) {
struct boxreader * box = lua_touserdata(L, 1);
stm_releasereader(box->obj);
box->obj = NULL;
stm_releasecopy(box->lastcopy);
box->lastcopy = NULL;
return 0;
}
static void
stm_release(struct stm_object *obj) {
assert(obj->copy);
WLock l(obj->lock);
// writer release the stm object, so release the last copy .
stm_releasecopy(obj->copy);
obj->copy = NULL;
if (--obj->reference > 0) {
// stm object grab by readers, reset the copy to NULL.
return;
}
// no one grab the stm object, no need to unlock wlock.
skynet_free(obj);
}
