线程可见性问题：如果我只在一个cpu上运行多线程。如果exieted变量visibity问题？

as titled: thread visibility issue: if I run multithreads on one cpu only.if exieted variable visibity issue? I think the threads will share the cache and not have any visibility , any other opinion ? Thanks at advanced.as titled: thread visibility issue: if I run mu