Go language mutex lock

sync.Mutex  The mutex 
type Mutex struct {
    
    //  Contains hidden or non exported fields 
}

Mutex It's a mutex , Fields that can be created as other structures ; Zero is the unlocked state .Mutex Type of lock is thread independent , It can be locked and unlocked by different threads .

Lock

func (m *Mutex) Lock()

Lock The method locks m, If m Locked , Then block until m Unlock .

Unlock

func (m *Mutex) Unlock()

Unlock Method unlock m, If m Not locking will result in runtime errors . Locks have nothing to do with threads , It can be locked and unlocked by different threads .

Mutexes are mutually exclusive , Whoever grabs the lock will execute it .

scene :

var mutex sync.Mutex				// The mutex 
func printer(str string){
    
	mutex.Lock()				// Lock 
	defer mutex.Unlock()		// Unlock 
	for _,ch:=range str{
    
		fmt.Printf("%c",ch)
		time.Sleep(time.Millisecond*300)
	}
}
func user1(){
    
	printer("hello ")
}
func user2(){
    
	printer("world")
}
func main() {
    
	go user1()
	go user2()
	for  {
    
		;
	}
}

result ： Every time 3 Millisecond output 1 Characters , Output... In sequence hello world 10 Characters

Use steps :
1.​ var lock sync.Mutex // Declare a mutex
​ 2.lock.Lock() // Lock
​ 3.lock.Unlock() // Unlock

For more details, please refer to ：http://blog.newbmiao.com/2019/10/10/go_mutex_insight.html