[Date Prev][Date Next][Thread Prev][Thread Next]
- Subject: Re: retrieve top-level lua_State?
- From: Florian Weimer <fw@...>
- Date: Sun, 07 Jun 2009 00:27:09 +0200
* David Ludwig:
> The memory of a coroutine's lua_State can get garbage collected and
> freed automatically, whereas the top-level state's memory will not get
> freed unless specifically asked. This can be a problem if a
> coroutine's code calls a C function, which then records the pointer of
> the passed-in lua_State. If the coroutine ends and its state gets
> freed, the C-side code may end up crashing if it tries to use that
> lua_State. One fix to this is to use the top-level state.
It's usually recommended to update the stored Lua state pointer with
the current call's state prior to calling back into Lua.
I struggled with this problem, too, and it's shared by other language
interfaces (notably JNI). You can store the current Lua state in a
thread-local variable if you want to accept this operating system
> One portable way to deal with this is to store a pointer to the
> top-level state as a userdata in the global environment. It's not the
> fastest solution, however it may be fast enough depending on what
> you're writing.
Would it also be possible to allocate a dedicated Lua thread for this