How is mutual exclusion (Mutex) implemented in programming systems?

In Go, the sync.Mutex type from the standard library is used to implement mutual exclusion (Mutex). A mutex provides exclusive access to shared resources, preventing multiple goroutines from executing the critical section simultaneously.

Example usage:

import (
    "fmt"
    "sync"
)

func main() {
    var mu sync.Mutex
    counter := 0

    mu.Lock()           // Acquire the mutex
    counter++           // Critical section
    mu.Unlock()         // Release the mutex

    fmt.Println(counter)
}

The mutex blocks other goroutines from executing code that tries to lock it until it is unlocked. This prevents race conditions when accessing shared data.