Handling out of order execution

Question

I recently stumbled upon this Wikipedia article. From my experience with multi-threading I am aware of the multitude of issues caused by the program being able to switch threads

Answer 1

The compiler and the cpu both implement algorithms which ensure that sequential semantics are preserved for a given execution stream. For them to not implement said algorithms qualifies as a bug. It is safe to assume that instruction reordering will not affect your program semantics.

As noted elsewhere, memory is the only place where non-sequential semantics may arise; synchronization to sequentialisms can be obtained there via various well-known mechanisms(at the assembly level, there are atomic memory access instructions; higher level functions such as mutexes, barriers, spinlocks, etc. are implemented with atomic assembly instructions).

In answer to your title: You don't handle OOO execution.