His note on resource cleanup doesn't really make sense -- or, rather, it only makes sense if you're using python's solutions for it. What about something like,

His note on resource cleanup doesn't really make sense -- or, rather, it only makes sense if you're using python's solutions for it. What about something like, say, c++ where you have a smart pointer that keeps track of the number of references to it, to store your file pointer? Then when you pass that to your concurrent function, it won't get cleaned up, until that other thread finishes, then that reference to it will be lost and it'll clean itself up.