The key point of the program order rule is: in a thread. Imagine this simple program (all variables initially 0): T1: x = 5; y = 6; T2: if (y == 6) System.out.println(x); From T1’s perspective, an execution must be consistent with y being assigned after x (program order). However from T2’s perspective this does … Read more
If you look at the underlying array reference you’ll see it’s marked as volatile. When a write operation occurs (such as in the above extract) this volatile reference is only updated in the final statement via setArray. Up until this point any read operations will return elements from the old copy of the array. The … Read more
Obviously the write to currentPos doesn’t happen-before the read of it, but I don’t see how that can be the issue. currentPos = new Point(currentPos.x+1, currentPos.y+1); does a few things, including writing default values to x and y (0) and then writing their initial values in the constructor. Since your object is not safely published … Read more