Java volatile Keyword - YooYoungmo/AEP GitHub Wiki https://dzone.com/articles/java-volatile-keyword-0 https://medium.com/google-developer-experts/on-properly-using-volatile-and-synchronized-702fc05faac2#.jwlkllxdr http://www.cs.umd.edu/~pugh/java/memoryModel/DoubleCheckedLocking.html