title: Reading from a field in multithreading
body: <p>As far as I understand any thread may create a <code>thread_local</code> cache of the variables one's going to read. Also, <code>volatile</code> field means any thread that reads the variable will get one's actual value and it doesn't depends on the value cached within the thread. So, should we declare a field as a volatile any time we're going to read one from some threads?</p>