There are times that you do not want any other child of the same process to change a file or even access it because you are changing its data and you do not want the other processes to read incomplete or inconsistent data. Although you will learn more about file locking and go routines in Chapter 9, Goroutines - Basic Features and Chapter 10, Goroutines - Advanced Features, this chapter will present a small Go example without a detailed explanation in order to give you an idea about how things work: you should wait until Chapter 9, Goroutines - Basic Features and Chapter 10, Goroutines - Advanced Features, to learn more.
The presented technique will use Mutex, which is a general synchronization mechanism. The Mutex lock will allow us to lock a file from within the same Go process. As a result, this technique has nothing to do with the use of the flock(2) system...
