Is mutex a thread synchronization tool?

Yes, mutex (mutual exclusion) is a synchronization tool for threads. In Go, it is represented by the sync.Mutex structure, which allows limiting concurrent access to shared resources, preventing race conditions. When one thread (goroutine) acquires the mutex, others attempting to acquire it are blocked until it is released.

Example of using mutex in Go:

var mu sync.Mutex
var counter int

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