golang的多线程固然好用，但是有时候需要对数据进行上锁，防止数据被其它线程更改。那么sync包下的Mutex非常好用。

Mutex是一个互斥锁。可以作为struct的一部分，这样这个struct就会防止被多线程更改数据。

来个例子：

package main

import (
	"fmt"
	"sync"
	"time"
)

type User struct {
	Name   string
	Locker *sync.Mutex
}

func (u *User) SetName(wati *sync.WaitGroup,name string) {
	defer func() {
		fmt.Println("Unlock set name:",name)
		u.Locker.Unlock()
		wati.Done()
	}()

	u.Locker.Lock()
	fmt.Println("Lock set name:",name)
	time.Sleep(1 * time.Second)
	u.Name = name
}

func (u *User) GetName(wati *sync.WaitGroup) {
	defer func() {
		fmt.Println("Unlock get name:",u.Name)
		u.Locker.Unlock()
		wati.Done()
	}()

	u.Locker.Lock()
	fmt.Println("Lock get name:",u.Name)
	time.Sleep(1 * time.Second)
}

func main() {
	user := User{}
	user.Locker = new(sync.Mutex)
	wait := &sync.WaitGroup{}
	names := []string{"a","b","c"}
	for _,name := range names {
		wait.Add(2)
		go user.SetName(wait,name)
		go user.GetName(wait)
	}

	wait.Wait()
}

Lock set name: a
Unlock set name: a
Lock get name: a
Unlock get name: a
Lock set name: b
Unlock set name: b
Lock get name: b
Unlock get name: b
Lock set name: c
Unlock set name: c
Lock get name: c
Unlock get name: c

文章来自：http://www.liguosong.com/2014/05/07/golang-sync-mutex/