Discussion on answer by HolyBlackCat: Ключевое слово volatile в C

Imported from a comment discussion on https://ru.stackoverflow.com/questions/1578082/%d0%9a%d0%bb%d1%8e%d1%87%d0%b5%d0%b2%d0%be%d0%b5-%d1%81%d0%bb%d0%be%d0%b2%d0%be-volatile-%d0%b2-c/1578088#1578088