I mentioned multithreaded programming a lot in the previous chapter, so it is not hard to guess where that path is taking me next. Multithreaded programming, or multithreading, is the art of running multiple parts of your program at the same time.

Multithreading is definitely not my first choice for improving existing code. It is hard to write multithreaded programs, and very simple to introduce problems that are then hard to find. Multithreaded programs are also very hard to debug.

To understand multithreading we should first know the processes and threads. In general terms, a process equates to a running program. A process encompasses application code, loaded in memory, and all the resources (memory, files, windows, and so on) used by the program.

A thread, on the other hand, represents a state of the program's execution. A thread is nothing more than the current state of the CPU registers, variables local to the thread (threadvar statement introduces...