What is the purpose of using a mutual exclusion mechanism (Mutex) in multithreaded programming?

The mutual exclusion mechanism (Mutex) in multithreaded programming is used to prevent multiple threads from accessing shared resources or critical sections of code simultaneously. This helps avoid race conditions, data corruption, and ensures the correct operation of the program.

In Go, this is often implemented using sync.Mutex:

var mu sync.Mutex
var counter int

func increment() {
    mu.Lock()           // acquire the mutex
    counter++           // critical section
    mu.Unlock()         // release the mutex
}

Thus, only one thread can execute the code between Lock and Unlock at a time.